MECHANISTIC INSIGHTS RELATED TO THE DESIGN AND CONSTRUCTION OF LITHIUM SINGLE ION CONDUCTORS By Gregory Spahlinger A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of Chemistry - Doctor of Philosophy 2014 ABSTRACT MECHANISTIC INSIGHTS RELATED TO THE DESIGN AND CONSTRUCTION OF LITHIUM SINGLE ION CONDUCTORS By Gregory Spahlinger Lithium single ion conductors are a class of electrolytes, typically designed for lithium ion batteries, with the potential to improve the performance of these batteries. The benefits of single ion conductors arise out of the fact that their immobile anions are not capable of concentrating near the anode of the battery, causing an increase in resistance as the battery is discharged. Unfortunately lithium single ion conductors suffer severe drawbacks in their conductivity which have been attributed to diverse causes. Because of the low success rate of single ion conductors in the literature and previous work in the Baker group, I have chosen to investigate mechanistic questions related to the design and construction of these materials, without engineering new materials. An attractive design strategy for the screening of immobile anion moieties for single ion conductors would be the use of the copper catalyzed alkyne azide (CUAAC) “click” reaction in order to efficiently introduce anions onto a support chemistry in a way that is efficient and tunable. A variable added by this strategy would be the presence of a 1,2,3-triazole moiety which is not commonly used in electrolyte chemistry. In order to assess the impact of the triazole on the conductivity of an electrolyte, a series of model compounds were synthesized containing a variable number of triazoles in an otherwise poly(ethylene glycol) like oligomer chain. The model compounds were subjected to differential scanning calorimetry, electrochemical impedance spectroscopy, and in one case single crystal X-ray diffraction, and solvent shells were modeled for lithium with and without triazoles using ab initio quantum chemistry calculations. It was concluded that the affinity to Li+ of the triazole and ether oxygen are similar, however the triazole has a substantial dipole which exerts some deleterious effects on the conductivity, leading to an increase in the activation energy for the process. These effects are balanced by an increase in the pre-exponential factor which leads to “compensation behavior” due to the dependence of that quantity on the dipole density in the material. The observed effect is one of a lower conductivity for the model compounds relative to poly(ethylene glycol)dimethyl ether 500 at room temperature, which converges to roughly the same conductivity around 80 °C. In synthetic studies, attempts were made to synthesize N-triflylpropanesultam (TPS) a five membered heterocycle whose nucleophilic ring opening would yield a desirable anion for use in single ion conductors. TPS proved to be significantly more difficult to open than expected, which prompted a computational study. In order to study the nucleofugality of polyatomic anionic leaving groups derived from oxygen and nitrogen, a contingent of 19 methylating agents consisting of amines or alcohols activated with carbonyl or sulfonyl substituents has been examined via ab initio calculations. Activation energies for alkylation of ammonia, and gas phase methyl cation affinitys were calculated. It was found that polyatomic anionic leaving groups derived from nitrogen will have higher activation energies for Menshutkin (SN2) alkylation even when they have similar methyl cation affinities. This inherent deficit in the nucleofugality of nitrogen derived leaving groups appears to be a result of the way bond cleavage is synchronized with bond formation to the incoming ammonia nucleophile. Additionally the second sulfonyl group present in a sulfonimide appears to be less effective at activating nitrogen due to a preference for tetrahedral geometries at nitrogen in the transition states of sulfonamide groups. Optimal delocalization of electron density is therefore frustrated due to the symmetry of the leaving group. Copyright by GREGORY SPAHLINGER 2014 iv To those who devote themselves to the pursuit and transmission of knowledge To those who have been my mentors and role models To science v ACKNOWLEDGMENTS My Ph.D. has been an epic journey and I’ve been fortunate to share it with many companions. I would like to recognize the support of my family, particularly Carol, Dave, Melissa, Diana, Bruce, Brenda, Nathan and my (too numerous to name individually) extended family, who have been there for me during some of the most difficult times in my life, and who have always supported me in my aspirations. Similarly I would like to acknowledge my friends and colleagues at MSU and otherwise. This includes Ned Jackson, and members of his group: Souful, Jason, Darya, Tayeb, Chao, Andrew, Fatmata, Mahlet, Jake, Gracie Lou and Misha who have been great friends and valued colleagues. I would also like to recognize Greg Baker, whose mentorship got me started in this program and some of his group: Zhe Jia, Gina, Salinda, Yu Ling, Olivia and Patty for largely the same reasons. Likewise I acknowledge my guidance committee Mitch Smith, Keith Promislow, Tom Hamann, and Xuefei Huang, for their role in my professional development. I acknowledge my friends from Ann Arbor: Marcus, Kim, Ted, Laura, Chuck and others for providing me an escape from East Lansing. I acknowledge Matt and the Lansing Pinball League for giving me someplace to evade calculations and think about a different kind of physics every couple of weeks, I acknowledge my friend Kristen for listening to my songs and cat stories, and my friend Xin for sharing an apartment with me for a couple years. I would also like to acknowledge the technical support staff who have helped me enable my research or directly contributed to this dissertation. This includes Richard Staples, who solved the crystal structures found in this work, Dan Holmes and Kermit Johnson who were both extremely helpful when NMR problems arose, Kathy Severin who helped me learn Labview, vi Paul Reed, who helped me troubleshoot calculations and gain access to the HPCC, Glenn Wesley who made my coin cell for electrochemical impedance spectroscopy, Scott Bankroff who constructed my mercury bubbler and cleaned my vacuum manifold, Bob Rasico who helped me troubleshoot the Baker glovebox, and Joni Tucker for jerry rigging my schedule this semester. Finally I would like to acknowledge the MSU college of Natural Science for conference and dissertation continuation fellowship funding, the MSU Chemistry IT department and Institute for Cyber Enabled Research (iCER) for access to computational resources, the MSU Center for Crystolographic Research for crystallographic services, The MSU center for Mass Spectrometry, for high resolution mass spectrometry analyses, and the MSU Chemistry Department for the 12 semesters of support I received as a teaching assistant. vii TABLE OF CONTENTS LIST OF TABLES ..................................................................................................................................... x LIST OF FIGURES ................................................................................................................................xvii LIST OF SCHEMES ...............................................................................................................................xxi KEY TO ABBREVIATIONS................................................................................................................ xxii 1 Chapter 1: Introduction ...................................................................................................................... 1 1.1 General Background .................................................................................................................. 1 1.2 Physical Models of Lithium Ion Transport in Liquid and Polymer Electrolytes ............... 3 1.3 Electrolyte Polarization in Lithium Ion Batteries ................................................................ 13 1.4 Design Strategies for the Improvement of Lithium Ion Electrolyte Performance ........... 14 1.5 Strategies of Single Ion Conductor Design from the Baker Research Group .................. 19 1.6 Problems with Single Ion Conductors Demonstrated in Experiment and Simulation .... 23 1.7 On the Construction of Lithium Single Ion Conductors and the Making of Lemonade . 26 2 Chapter 2: 1,2,3-Triazoles as Pseudo-Ether Moieties in Oligo (Ethylene Glycol) Based Lithium Ion Electrolytes .......................................................................................................................... 31 2.1 Introduction ............................................................................................................................... 31 2.2 Experimental ............................................................................................................................. 34 2.2.1 Computational methods ................................................................................................... 34 2.2.2 Electrochemical Impedance Spectroscopy.................................................................... 35 2.2.3 Single Crystal X-Ray Diffraction ................................................................................... 36 2.2.4 Synthesis of Model Compounds..................................................................................... 38 2.2.4.1 Materials and Instrumentation .................................................................................... 39 2.2.4.2 Synthesis of Tosylates 1 – 5........................................................................................ 39 2.2.4.3 Synthesis of Azides 6 – 8 ............................................................................................ 41 2.2.4.4 Synthesis of Alkynes 9 – 11........................................................................................ 43 2.2.4.5 Synthesis of Model Compounds 12 – 15127 .............................................................. 44 2.3 Results and Discussion ............................................................................................................ 47 2.3.1 Ab Initio Calculations ...................................................................................................... 47 2.3.2 Experimental Measurement of Conductivity and Thermal Behavior ........................ 52 2.3.3 The Explanation for and Significance of Compensation Behavior ........................... 60 2.4 Conclusions ............................................................................................................................... 67 3 Chapter 3: Nucleofugality in Nitrogen and Oxygen derived leaving groups ........................... 68 3.1 Introduction ............................................................................................................................... 68 3.2 Computational Methods .......................................................................................................... 71 3.3 Results and Discussion ............................................................................................................ 74 3.3.1 Energies Associated with Nucleofugality, and their Trends....................................... 74 3.3.2 On the Fitness of MCA to Describe Inherent Nucleofugality .................................... 83 3.4 Conclusion ................................................................................................................................. 94 viii 4 Chapter 4: Summary and Future Study ........................................................................................ 95 4.1 Summary.................................................................................................................................... 95 4.2 Future Directions for CUAAC Derived Lithium Single Ion Conductors ......................... 97 4.3 Future Directions for Studies of Nucleofugality in Activated Leaving Groups .............. 99 APPENDICES ........................................................................................................................................ 101 4.4 Appendix 1 – Additional Study of TPS............................................................................... 102 4.5 Appendix 2 – Spectal Data and Geometric Results from Computations ........................ 113 REFERENCES ....................................................................................................................................... 176 ix LIST OF TABLES Table 1 – Physical Data Pertaining to Thermal and Conductive Properties of Materials ............ 53 Table 2 – Crystal Data and Structure Refinement for 6EO2T ...................................................... 59 Table 3 – Calculated ΔES→TS values and Relevant Transition State Geometries ......................... 79 Table 4 – Methyl Cation Affinity in Experiment and Theory. All values are in kcal/mol. .......... 80 Table 5 – Transition State Pyramidalization in Sulfonamide Species at HF and MP2 geometries (all values are given in degrees).................................................................................................... 93 Table 6 – Crystal Data and Structure Refinement for TPS ......................................................... 108 Table 7 – Comparison Between the Crystal Geometry of TPS and Geometry at MP2(full)/631G(d) (Bond Lengths) ............................................................................................................... 110 Table 8 – Comparison Between the Crystal Geometry of TPS and Geometry at MP2(full)/631G(d) (Bond Angles) ................................................................................................................ 111 Table 9 - Glyme, Energy: -307.87678 ........................................................................................ 119 Table 10 - Glyme-(Li+), Complex Energy: -315.22669 ............................................................. 119 Table 11 - Glyme + DME, Energy: -462.40188 ......................................................................... 120 Table 12 - Glyme-(Li+)-DME, Energy: -469.796041 ................................................................ 121 Table 13 - Glyme + Glyme, Energy: -615.75824 ....................................................................... 122 Table 14 - Glyme-(Li+)-Glyme, Energy: -623.18874 ................................................................ 123 Table 15 - 4-Methoxymethyl-1,2,3-Triazole, Energy: -394.90167 ............................................ 124 Table 16 - 4-Methoxymethyl-1,2,3-Triazole-(Li+), ................................................................... 124 Table 17 - 4-MeOMe-1,2,3-Triazole + DME, Energy: -549.42683 ........................................... 125 x Table 18 - 4-MeOMe-1,2,3-Triazole-(Li+)-DME, ..................................................................... 126 Table 19 - 4-MeOMe-1,2,3-Triazole + Glyme, Energy: -702.78713 ......................................... 127 Table 20 - 4-MeOMe-1,2,3-Triazole-(Li+)-Glyme, ................................................................... 128 Table 21 - Water, Energy: -76.23099 ......................................................................................... 129 Table 22 - Water-Li, Energy: -83.56307 ................................................................................... 129 Table 23 - 1H-1,2,3-Triazole, Energy: -241.56224 .................................................................... 129 Table 24 - 1H-1,2,3-Triazole-(Li+), Energy: -248.91584 .......................................................... 129 Table 25 - 2H-1,2,3-Triazole, Energy: -241.57086 .................................................................... 130 Table 26 - 2H-1,2,3-Triazole-(Li+), Energy: -248.89669 .......................................................... 130 Table 27 – Pyrazole, Energy: -225.55411 .................................................................................. 130 Table 28 - Pyrazole-(Li+), Energy: -232.89344 ......................................................................... 131 Table 29 - Pyridizine, Energy: -263.52492 ................................................................................. 131 Table 30 - Pyridazine-(Li+), Energy: -270.88587 ...................................................................... 131 Table 31 - Pyrimidine, Energy: -263.55995 ............................................................................... 132 Table 32 - Pyrimidine-(Li+), Energy: -270.89194...................................................................... 132 Table 33 - 1-Methoxyethyl-1,2,3-Triazole, Energy: -434.13854 ............................................... 133 Table 34 - 1-Methoxyethyl-1,2,3-Triazole-(Li+), ...................................................................... 133 Table 35 - 4-Methoxymethyl-1,2,3-Triazole, Energy: -394.95807 ............................................ 134 Table 36 - 4-Methoxymethyl-1,2,3-Triazole-(Li+), ................................................................... 134 Table 37 - Methyl Mesylate, Cs, Energy: -758.53145 ................................................................ 135 xi Table 38 - Dimethylsulfate, C1, Energy: -833.56441 ................................................................. 136 Table 39 - Methyl Triflate, C1, Energy: -1055.61053................................................................. 136 Table 40 - Methylfluorosulfonate, C1, Energy: -818.40115 ....................................................... 137 Table 41 - Methyl TFSI (anti) C1, Energy: -1919.67259 ........................................................... 137 Table 42 - Methyl TFSI (gauche) C1, Energy: -1919.67076 ...................................................... 138 Table 43 - Methyl FSI, C1, Energy: -1445.25353 ....................................................................... 138 Table 44 - Methyl MSI (anti) C1, Energy: -1325.52993 ............................................................. 139 Table 45 - Methyl MSI (gauche) C1, Energy: -1325.52302 ....................................................... 140 Table 46 - Methyl MSA, C1, Energy: -738.64549 ...................................................................... 140 Table 47 - Methyl FSA, C1, Energy: -798.52240 ....................................................................... 141 Table 48 - MeiprFSA, C1, Energy: -916.03637 ......................................................................... 141 Table 49 - Methyl Acetate, Cs, Energy: -323.88097.................................................................. 142 Table 50 - Methyl Trifluoroacetate, Cs, Energy: -620.97437 ..................................................... 142 Table 51 - Methyl Cyanoformate, Cs, Energy: -376.72778 ........................................................ 143 Table 52 - Dimethylcarbonate, Cs, Energy: -398.92298 ............................................................. 143 Table 53 - Dimethylurethane, Cs, Energy: -379.04927............................................................... 144 Table 54 - Methyl Acetamide, Cs, Energy: -304.00329 ............................................................. 144 Table 55 - Methyl Trifluoroacetamide, Cs, Energy: -601.10242 ................................................ 145 Table 56 - Methylcyanoformamide, Cs, Energy: -356.85536 ..................................................... 145 Table 57 - Methyl Succinimide, Cs, Energy: -455.08510 ........................................................... 146 xii Table 58 - 1,3-Propanesultone, C1, Energy: -796.52517 ............................................................ 146 Table 59 - N-Triflylpropanesultam, C1, Energy: -1660.59152 ................................................... 147 Table 60 - Methyl Chloride, C3v, Energy: -555.66764 ............................................................... 147 Table 61 - Methyl Mesylate, C1, Energy: -758.58709 ................................................................ 148 Table 62 - Dimethylsulfate, C1, Energy: -833.61240 ................................................................. 148 Table 63 - Methyl Triflate, C1, Energy: -1055.65367................................................................. 149 Table 64 - Methylfluorosulfonate, C1, Energy: -818.44356 ....................................................... 149 Table 65 - Methyl TFSI (anti) C1, Energy: -1919.72254 ............................................................ 150 Table 66 - Methyl TFSI (gauche) C1, Energy: -1919.71949 ...................................................... 151 Table 67 - Methyl FSI, C1, Energy: -1445.30276 ....................................................................... 151 Table 68 - Methyl MSI (anti) C1, Energy: -1325.59716 ............................................................. 152 Table 69 - Methyl MSI (gauche) C1, Energy: -1325.59135 ....................................................... 153 Table 70 - Methyl MSA, C1, Energy: -738.74012 ...................................................................... 153 Table 71 - Methyl FSA, C1, Energy: -798.60455 ....................................................................... 154 Table 72 - MeiprFSA, C1, Energy: -916.11962 .......................................................................... 154 Table 73 - Methyl Acetate, C1, Energy: -323.95778 ................................................................. 155 Table 74 - Methyl Trifluoroacetate, C1, Energy: -621.03443 ..................................................... 155 Table 75 - Methyl Cyanoformate, Cs, Energy: -376.78433 ........................................................ 156 Table 76 - Dimethylcarbonate, C1, Energy: -398.99274 ............................................................ 156 Table 77 - Dimethylurethane, C1, Energy: -379.16693 .............................................................. 157 xiii Table 78 - Methyl Acetamide, C1, Energy: -304.12207 ............................................................. 157 Table 79 - Methyl Trifluoroacetamide, C1, Energy: -601.21078 ................................................ 158 Table 80 - Methylcyanoformamide, Cs, Energy: -356.96347 ..................................................... 158 Table 81 - Methyl Succinimide, C1, Energy: -455.18368........................................................... 159 Table 82 - 1,3-Propanesultone, C1, Energy: -796.58767 ............................................................ 159 Table 83 - N-Triflylpropanesultam, C1, Energy: -1660.66338 ................................................... 160 Table 84 - Methyl Chloride, C3v, Energy: -555.73069 ............................................................... 160 Table 85 - Methyl Mesylate, Cs, Energy: -702.21914 ................................................................ 161 Table 86 - Dimethylsulfate, C1, Energy: -777.24377 ................................................................. 161 Table 87 - Methyl Triflate, C1, Energy: -999.28488.................................................................. 162 Table 88 - Methylfluorosulfonate, C1, Energy: -762.07625 ....................................................... 162 Table 89 - Methyl TFSI (anti) C1, Energy: -1863.35495 ............................................................ 163 Table 90 - Methyl FSI, C1, Energy: -1388.93439 ....................................................................... 163 Table 91 - Methyl MSI (anti) C1, Energy: -1269.22819 ............................................................. 164 Table 92 - Methyl MSA, C1, Energy: -682.37105 ...................................................................... 164 Table 93 - Methyl FSA, C1, Energy: -742.23853 ....................................................................... 165 Table 94 - MeiprFSA, C1, Energy: -859.75289 .......................................................................... 165 Table 95 - Methyl Acetate, Cs, Energy: -267.59323................................................................... 166 Table 96 - Methyl Trifluoroacetate, Cs, Energy: -564.66942 .................................................... 166 Table 97 - Methyl Cyanoformate, Cs, Energy: -320.41939 ........................................................ 166 xiv Table 98 - Dimethylcarbonate, Cs, Energy: -342.62576 ............................................................. 167 Table 99 - Dimethylurethane, C1, Energy: -322.79444 .............................................................. 167 Table 100 - Methyl Acetamide, C1, Energy: -247.75036 ........................................................... 167 Table 101 - Methyl Trifluoroacetamide, Cs, Energy: -544.83515 .............................................. 168 Table 102 - Methylcyanoformamide, Cs, Energy: -300.58450 ................................................... 168 Table 103 - Methyl Succinimide, Cs, Energy: -398.81698 ......................................................... 168 Table 104 - Methyl Chloride, C3v, Energy: -499.36908 ............................................................. 169 Table 105 - Mesylate (-) C3v, Energy: -662.53310 ..................................................................... 170 Table 106 - Methylsulfate (-) Cs, Energy: -737.57487 ............................................................... 170 Table 107 - Triflate (-) C3v, Energy: -959.63081 ........................................................................ 170 Table 108 - Fluorosulfonate (-) C3v, Energy: -722.42035 .......................................................... 171 Table 109 - TFSI (anti)(-) C2, Energy: -1823.69893 .................................................................. 171 Table 110 - FSI (-)C2, Energy -1349.28297 ............................................................................... 171 Table 111 - MSI (anti)(-) C2, Energy: -1229.53832 ................................................................... 172 Table 112 - MSA (-) C1, Energy: -642.63252 ............................................................................ 172 Table 113 - FSA (-) C1, Energy: -702.52414 .............................................................................. 172 Table 114 - Isopropyl FSA (-) C1, -820.03729 ........................................................................... 173 Table 115 - Acetate (-) Cs, Energy: -227.85413 ......................................................................... 173 Table 116 - Trifluoroacetate (-) Cs, Energy: -524.96954............................................................ 173 Table 117 - Cyanoformate (-) C2v, Energy: -280.73023 ............................................................. 173 xv Table 118 - Methylcarbonate (-) Cs, Energy: -302.90805 .......................................................... 174 Table 119 - Methylurethane (-) Cs, Energy: -283.02333 ........................................................... 174 Table 120 - Acetamide (-) Cs, Energy: -207.96859 .................................................................... 174 Table 121 - Trifluoroacetamide (-) Cs, Energy: -505.08677 ...................................................... 174 Table 122 - Cyanoformamide (-) Cs, Energy: -260.84632 ......................................................... 175 Table 123 - Succinimide (-) C2v, Energy: -359.07164 ................................................................ 175 xvi LIST OF FIGURES Figure 1 - A Schematic of a lithium ion battery, featuring typical materials for the anode (graphite) and the cathode (LiCoO2). A likely choice of electrolyte would be ethylene carbonate and dimethyl carbonate 1:1.1 Figure 1 is reprinted with permission from Bruce, P.; Scrosati, B.; Tarascon, J. Angew. Chem. Int. Ed. 2008, 47, 2930 – 2946. Copywrite 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. .................................................................................................... 2 Figure 2 - Rouse theory describes a polymer chain as a series of balls connected by springs.A hypothetical Rouse chain contains NR segments of 1 bead and 1 spring; beads have a designation l which starts at 0 such that l = NR at the end of the chain. The end to end distance vector of the chain is R, and the mean square length of a segment is aR, such that a Gaussian distribution of segment lengths exist in the chain (length variability not represented above).22............................ 8 Figure 3 – Three mechanisms (M) and times (τ) are associated with lithium ion transport Rouse model adapted theory of Maitra and Heuer. Lithium diffusion parallel to a chain, chain relaxation, and chain to chain transfer.23 ...................................................................................... 10 Figure 4 – The Maitra and Hueur model as compared to experimental data. N denotes the number of rouse segments in the model, while D is the coefficient of diffusion. Experimental data comes from the work of Shi et al.42 DM is the coefficient of diffusion from the three mechanisms discussed above and Dc.m. arises from diffusion of the polymer chain with associated lithium ions. Figure 4 has been reprinted with permission from Maitra, A.; Hueur, A. Phys. Rev. Lett. 2007, 98, 227802. http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.98.227802 Copywrite 2007, American Physical Society. .............................................................................. 12 Figure 5 – Lithium ion transference, T+, is a figure of merit describing the relative mobility of the cation and anion. It is defined as the ratio of the initial current which passes through an electrolyte (which drops during discharge) and the current flowing once an equilibrium has been established.4, 132 ............................................................................................................................. 14 Figure 6 – Silicate functionalized fillers used in the nanocomposites of the Baker (top) and Archer groups (bottom two). 27,29,30............................................................................................... 16 Figure 7 – Monomers produced by Kerr et al. (left) produced a crosslinked single ion conducting solid in the presence of a platinum catalyst. Endo et al. produced monomers (right) which could produce the same effect when heated.32,33 .................................................................................... 17 xvii Figure 8 – Nanoparticle designed of Asfour (top), and the most conductive design of Zhao (middle) and an attempt to improve the interfacial properties of synthesized polyelectrolytes (bottom). Polyelectrolytes allow for higher ratios of lithium to oxygen, but have not improved conductive performance to date.4, 26.............................................................................................. 20 Figure 9 – Proposed fillers for nanocomposite conductors. Clickable Particle 9 can be used to access designs 10 and 23 among others. ....................................................................................... 23 Figure 10 – Tethering anions to a host material has a dramatic deleterious effect on the conductivity of single ion conductors.20 Image reprinted with permission from Borodin, O.; Smith, G. D.; Geiculescu, O.; Creager, S. E.; Hallac, B.; DesMarteau, D. J. Phys. Chem. B 2006, 110, 24266 – 24274. Copywrite 2006, American Chemical Society........................................... 24 Figure 11 – Ohno-like triple ions proposed as novel single ion conductors. ................................ 28 Figure 12 – Three attempts to synthesize triple ions. The last of these featured TPS, a previously unknown molecule whose reactivity was much less pronounced than expected, sparked interest in the nucleofugality of polyatomic anionic nitrogen nucleofuges. .............................................. 29 Figure 13 – As more solvent moieties are added to the lithium coordination sphere the average bond strength decreases, effecting both triazole and ether ligands. Triazoles can interact with the 2p orbitals of the lithium ion leading to net stabilization in the two and three coordinate complexes which are planar. Lithium becomes sp3 hybridized in the tetracoordinate complex, and this effect is seen to diminish. Simulations and experimental data have shown four and five membered complexes to be most common in polyether ion conductors.19 .................................. 49 Figure 14 – Gas phase lithium ion to ligand affinities in experiment and theory. Typical agreement between the experiments of Rodgers et al.51-54 and the MP2(full)/Aug-cc-pVTZ(LiC)//MP2(full)/cc-pVDZ(Li-C) calculations recommended by the same group for quantitatively accurate lithium ion affinities are shown in (a) .51 Calculations typically over estimate affinities relative to experiment but are usually within 10 kJ/mol, which is comparable to the uncertainty of the experiment. In (b) G3 methods were compared to the methods of Rodgers et al. due to unfavorable scaling of the latter to larger ligand systems.51 The computational expense of G3 is similar to that of the Rodgers method, with G3(MP2) being somewhat cheaper. G3(MP2) was found to be in better agreement with experiment due to being consistently lower in its energy estimates. ....................................................................................................................................... 50 xviii Figure 15 – Conductivity of oligomer salt complexes. In (a) model oligomer salt complexes were run at a concentration of 1 Li : 64 ligand atoms, where two of the triazole nitrogens were considered ligands (but not the pyrrole-like nitrogen) run with PEG 500 dimethyl ether controls. Model oligomers and the PEG control were run with LiTFSI, while a variable concentration standards curve was run with LiClO4. In (b) the same data shown without standards. ................ 54 Figure 16 – Descriptions of trends in the conductivity of oligomer salt complexes. In part (a) a strong correlation between conductivity at 30°C and the glass transition temperature is found within the model series. In part (b) a linear relation is shown between the pre-exponential factor and activation derived from Arrhenius plotting in PEG and the triazole containing model compounds. ................................................................................................................................... 55 Figure 17 – Single crystal X-ray diffraction of 6EO2T. In part (a) the Single Crystal XRD structure of 6EO2T is shown with thermal elipsoids set at 50% probability. Packing as viewed from the b axis of the 6EO2T crystal is shown in (b) and the c axis in (c). While a layered structure is evident in the crystal, pi-pi stacking interactions and hydrogen bonding appear to be absent. The angle shown in (c) reveals that triazole moieties align roughly along the dipole of the ring within the layers. ................................................................................................................... 57 Figure 18 – Computed Barrier Heights from the MP2/G3large level of theory. Thermal corrections for the ΔH values were computed at 298K. ............................................................... 78 Figure 19 – Barrier heights are very well predicted by methyl cation affinities within subsets derived from oxygen and nitrogen, but less so in the full set. Nitrogen leaving groups universally have higher barriers at a given value of MCA. ............................................................................. 83 Figure 20 – Correlations between ΔES→Ts, MCA and bond length. ΔES→Ts correlates very strongly to methyl leaving group bond length, as a percentage of its value in the parent methylating agent at its ground state (a) This is also true for the MCA (b) which shows that our simulated reactions obey the Hammond postulate........................................................................ 84 Figure 21 – Dependence of activation energy on theoretical method. At HF/6-31G(d) Methyl FSI and Methylfluorosulfonate have the same activation energy. When the wave function is correlated FSI is found to have a higher activation energy by several kcal/mol. Additional MP2 and CCSD(T) calculations at the MP2(full)/6-31G(d) geometry confirm this trend. Of the leaving groups calculated, only the sulfonimides show a higher activation energy at MP2(full)/6-31G(d) than HF/6-31G(d).......................................................................................................................... 85 xix Figure 22 – Nitrogen leaving groups exhibit more extensive C-X bond elongation in their transition states than do oxygen groups. This is very apparent when raw bond lengths are compared (a) But this trend holds up even when %C-X elongation is used to correct for the longer C-N bonds present in the parent alkylating agents (b). ..................................................... 86 Figure 23 – A correlation is evident between the transition state HOMO energy and the magnitude of ΔES→TS. ................................................................................................................... 88 Figure 24 – Natural charge on the leaving group atom correlates with ΔES→TS. ......................... 89 Figure 25 – The transition states of nitrogen leaving groups become progressively more bent as C-X bond gets longer. No such trend occurs in oxygen leaving groups....................................... 90 Figure 26 – Some origins in the gap between the nucleofugality of sulfonimide and sulfonate leaving groups can be linked to differences in the electronic structure. Imide spanning orbitals such as HOMO-5 in FSI ( Top Left) have better overlap in the planar HF/6-31G(d) geometry ( left) In the MP2(full)/6-31G(d) geometry (Right) HOMO-5 and HOMO-6 mix. Presumably these bonding interactions are opposed by n → σ* interactions localized to one sulfonyl group or the other. ............................................................................................................................................. 92 Figure 27 – The crystal structure of TPS. A view of a single molecule is shown in part a with thermal elipsoids shown at 50% probability. The packing along the b axis of the crystal is also shown (b). ................................................................................................................................... 109 Figure 28 – Homeodesmotic reactions used to calculate the strain energy of sulfonyl herterocycles. .............................................................................................................................. 112 Figure 29 - 6EO2T ...................................................................................................................... 114 Figure 30 - 8EO2T ...................................................................................................................... 115 Figure 31 - 6EO1T ...................................................................................................................... 116 Figure 32 - 8EO1T ...................................................................................................................... 117 Figure 33 - N-Triflylpropanesultam (TPS) ................................................................................. 118 xx LIST OF SCHEMES Scheme 1 – Model compounds with whole number triazole to ether oxygen ratios. Each has a name derived from the number of ether oxygens and triazoles in the compound, hence “8 ether oxygens, 2 triazoles” becomes “8EO2T”...................................................................................... 33 Scheme 2 – Synthesis of triazole containing poly(ethylene glycol) based model oligomers ..... 38 Scheme 3 – Relevant energies are derived from electronic structures calculated along the reaction coordinate of an SN2 reaction (A) The difference in energy between a methylating agent in its bound state, and the sum of the separated ions after heterolytic cleavage is defined as the methyl cation affinity (MCA) (B) ................................................................................................. 75 Scheme 4 – Alkylating agents and the names they are referred to by in this study.................... 77 Scheme 5 – Proposed materials and synthesis for the investigation of triazoles as an activating moiety in lithium single ion conductors........................................................................................ 98 Scheme 6 – Synthetic Route from 1,3 Propane sultone to TPS. ................................................. 103 xxi KEY TO ABBREVIATIONS CUAAC – Copper Catalyzed Alkyne Azide Reaction TPS- N-Triflylpropanesultam PEG- Poly(ethylene glycol) PEO – Poly(ethylene oxide) DBP – dynamic bond percolation model DDH – dynamically disordered hopping model VTF – Vogel Tamman Fulcher σ - conductivity V – volts or potential I – Current R – Resistance or the Gas constant (context dependant) G - Conductance S - Siemens Ω – Ohms μ – mobility or dipole moment (context dependent) q – charge D – coefficient of diffusion Λm – Molar conductivity F – Faraday’s constant T – Temperature z - charge count ν – stoichiometric coefficient Tg – Glass transition temperature xxii Tm – Melting transition temperature k or kB – Bolzmann’s constant σ0 – exponential prefactor for conductivity in Arrhenius or VTF formalisms Ea – activation energy P(t) – probability of an event as a function of time wi→j – Probability of a transition τren – Renewal time r - Displacement - mean squared displacement of a particle (triangular braces always denote an ensemble average) Ts – Shifted temperature TFSI – bis(trifluoromethanesulfonyl)imide MSD(t) – mean squared displacement of a particle as a function of time a(T) – temperature dependent shift factor NR – the number of Rouse segments (a bead connected to a spring) in a modeled chain l – numerical designation of a rouse segment aR – mean squared distance between rouse beads R – vector describing the shortest distance between the ends of a polymer chain ζR – Coefficient of friction M1 – mechanism 1 of Li+ diffusion (diffusion along polymer chains) M2 - mechanism 2 of Li+ diffusion (diffusion mediated by chain deformation) M3 – mechanism 3 of Li+ diffusion (diffusion by chain hopping) τ1, τ2, and τ3 – times associated with the above mechanisms (M1 through M3) R0 – initial value of R Re – equilibrium value of R xxiii DM – diffusion resulting from the three mechanisms detailed above Dc.m. – diffusion resulting from movement of a lithium resulting from center of mass displacement of the polymer chain T+ - Lithium ion transference number PEGDME – Poly(ethylene glycol) dimethyl ether APTES – 3-aminopropyltriethoxysilane 6EO2T – A model compound, “6 ether oxygens 2 triazoles” 8EO2T – “8 ether oxygens 2 triazoles” 8EO1T – “8 ether oxygens 1 triazole” 6EO1T – “6 ether oxygens 1 triazole” GAMESS – General Atomic and Molecular Electronic Structure System – a computational software package HF – Hartree Fock MP2 – Moller Plesset second order perturbation theory MP2(full) – MP2 calculation where perturbative correction is applied to all electrons including core electrons MP2(FC) – MP2 “frozen core” where only valence electrons receive perturbative correction. This is the default MP2 treatment, and FC need not be explicitly specified. CCSD – Coupled Cluster Singles and Doubles QCISD(T) – Quadratic Configuration Interaction Singles Doubles and non-iterative Triples CCSD(T) – Coupled Cluster Singles Doubles and non-iterative Triples B3LYP – “Becke 3 parameter Lee-Yang-Parr”, B3LYP is a hybrid functional and the most common functional used in density functional theory. G3 – Gaussian 3 theory G3(MP2) – Gaussian 3 with reduced Moller Plesset order cc-pVDZ or cc-pVTZ – common Dunning basis sets. DZ is double zeta TZ is triple zeta Aug-cc-pVNZ – Dunning basis set with added diffuse functions xxiv Aug-cc-pVNZ(Li-C) – Dunning basis set with core correlation functions on lithium 3-21G – a Pople minimal basis set 6-31G(d) – a common Pople basis set of double zeta quality. Contains a d function for polarization on first row atoms. ΔE – a change in energy ΔEass – association energy of a ligand to a metal Ecomplex – the energy of a complex Eligand – the energy of a ligand ELi – energy of a lithium atom or ion THF – tetrahydrofuran NMR – nuclear magnetic resonance spectroscopy IR – infrared spectroscopy Ts – Tosyl or p-toluenesulfonyl 4-MEOMET – 4-methoxymethyltriazole 1-MEOET – 1-methoxyethyltriazole Mn – number average molecular weight Å – angstrom TD – Disordering temperature εs – static dielectric constant Nd – dipole density D – Debye (chapter 2 only) I – Ionization energy (chapter 3 only) A – Electron affinity (chapter 3 only) μ – electronic chemical potential (chapter 3 only) η – chemical hardness (chapter 3 only) xxv ω – electrophilicity ΔEnucleofuge – an energy scale to describe the ease with which a nucleofuge departs HPCC – High Performance Computing Cluster MAD – Mean Average Deviation MCA – Methyl Cation Affinity ΔES→TS – the difference between separated species and transition states ΔE‡ - the difference between an association complex and a transition state %BE – percentage bond elongation MSI – (methylsulfonyl)imide FSI – (fluorosulfonyl)imide FSA – fluorosulfonamide MSA – methylsulfonamide MeiprFSA – methyl isopropyl fluorosulfonamide Ec – Crossing energy B – quantum mechanical resonance energy (chapter 3 only) HOMO – Highest Occupied Molecular Orbital LUMO – Lowest Unoccupied Molecular Orbital s – singlet d – doublet dd – doublet of doublets t – triplet q – quartet p – pentet m - multiplet xxvi 1 1.1 Chapter 1: Introduction General Background In the overall scheme of fuels and energy storage technology, batteries play an important and ever increasing role. With an increasing need for a sustainable, carbon-neutral energy economy, the need for safe, energy dense batteries capable of translating electrical energy into such technologies as light duty vehicles is also increasing.1 Lithium ion batteries are one of the most famous and promising technologies with the potential to fill this niche.2 The Lithium ion battery was first proposed in 1976 based on lithium intercalation into a TiS2 cathode.3 Energy storage in a lithium ion battery is facilitated by the difference in electron affinity between Li0, which is strongly electropositive, and an oxidizing transition metal center.4 During the discharge process of the battery, electrons flow from the anode (lithium metal or an intercalation compound such as lithium intercalated graphite) through an outside circuit, providing energy to a device, and finally to the cathode where they reduce the cathode material, which is usually a transition metal chalcogenide.1 The accompanying process within the cell consists of lithium atoms undergoing oxidation in the anode and traveling as Li+ through the electrolyte and into the cathode, where they intercalate to balance the reduction of the cathode material.1 1 Figure 1 - A Schematic of a lithium ion battery, featuring typical materials for the anode (graphite) and the cathode (LiCoO2). A likely choice of electrolyte would be ethylene carbonate and dimethyl carbonate 1:1.1 Figure 1 is reprinted with permission from Bruce, P.; Scrosati, B.; Tarascon, J. Angew. Chem. Int. Ed. 2008, 47, 2930 – 2946. Copywrite 2008 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim. The electrolyte of a lithium ion battery is a solvent capable of dissociating a lithium salt, and allowing the ions to migrate under an applied potential. Such solvents must be relatively polar, and relatively unreactive toward the anode and cathode.4,5 The most common choices of electrolytes are solutions of the lithium salts of strong acids such as LiSO3CF3 or LiClO4, in polar aprotic organic solvents such as propylene carbonate, dimethyl carbonate or tetrahydrofuran.4,6 The conductivities of optimized electrolytes of this class may be as high as 10-2 S/cm at room temperature.4,6 Most of the drawbacks of liquid electrolytes are straightforward consequences of the fact that they are organic liquids. Organic electrolytes are flammable, and may leak from a damaged battery casing.7 Lithium metal anodes may not be used with most liquid electrolytes, as they are 2 too reactive.4,7 Additionally, the application of an over potential during the charging process can cause dendrites of lithium metal to form which can lead to reduced capacity and failure of the battery.4,7 These drawbacks have led to the development of solid polymer electrolytes, particularly for applications in electric vehicles.7 Solid polymer electrolytes should, in theory, be capable of resolving many of the problems associated with liquid electrolytes, and these systems have been the focus of intensive study since Wright and Armand first reported the conductivity of salt complexes of polyethylene glycol in the late 1970s.5 Polyethylene glycol (PEG or PEO) is a linear polymer of the formula (CH2CH2O)n which is capable of acting as a solvent for alkali metal salts. Polyethylene glycol based electrolytes run into their own problems, however, due to ionic conductivities which are dramatically lower than those of liquid electrolytes; on the order of 10-5 S/cm or less. 1.2 Physical Models of Lithium Ion Transport in Liquid and Polymer Electrolytes The conductivity of a lithium electrolyte is the inverse of its resistance as given by Ohm’s law V=IR, such that conductivity (σ) can be understood as a measure of current (I) per unit potential (V).4,5 Conductivity is an intensive property of the system derived from the extensive property Conductance (G) through the relation σ=Gl/A, where A is the cross sectional area of a sample and l is the thickness.8 G is typically reported in Siemens (S) which are the inverse of Ohms (Ω) the SI unit for resistance. Conductivity is therefore typically given in S/cm. Physics and physical chemistry have well defined tools for understanding the conductivity of dilute aqueous solutions of ions, which have been understood for decades. If full dissociation and independent motion of ions are assumed, then conductivity can be related to the mobilities of the ions by the Kohl-Rausch summation: 3 𝜎 = ∑𝑖 𝜇𝑖 𝑛𝑖 𝑞𝑖 (eq. 1) where μ is the carrier mobility, n is the carrier concentration, and q is the charge of the carrier species in the electrolyte.4,5,9 Additionally, molar conductivity (Λm) can be related to the sum of the coefficients of diffusion (D) of ions in a solution by the Nernst-Einstein equation: 𝐹2 𝛬𝑚 = 𝑅𝑇 ∑𝑖 𝐷𝑖 𝑧𝑖2 𝜈𝑖 (eq. 2) Where F is Faraday’s constant, R is the gas constant; T is the temperature of the system, z is the charge of the ion and ν is the count of the ion in the chemical formula (e.g. the Cl(-) in ZnCl2 would have ν = 2, while Zn(2+) would have z = 2).5,8,9 Conceptually, these relationships still hold in liquid and solid polymeric lithium ion electrolytes, but they become less and less useful for describing the conductivity of a system, as lithium ion conductors tend to be more concentrated, non-aqueous, and have less than full dissociation.5,9,10 Polymer hosts for lithium electrolytes do exhibit local fluidity analogous to ionic solutions, provided they are amorphous rather than crystalline, and provided they are above their glass transition temperature (Tg).5 The importance of side chain flexibility can be understood by invoking the Vogel Tamman Fulcher (VTF) model of conductivity, a modified Arrhenius equation: −𝐵 𝜎𝑇 = 𝜎0 𝑒 𝑘(𝑇−𝑇0) (eq. 3) wherein temperature T is normalized by subtracting the equilibrium glass transition temperature T0 which is generally considered to be a value ‘close to’ but not equal to Tg.5 This rationalization 4 is made based on the fact that the polymer behaves as a frozen solid beneath its glass transition temperature, and thermal energy cannot enhance segmental motion below this point.5 Ratner, Nitzan and co-workers have attempted to derive a more satisfactory model, a Dynamic Bond Percolation theory (DBP) their model builds on static bond percolation: a microscopic theory of diffusion based on the probability of ionic movement in a disordered material whose local structure is stationary.5, 9, 11-15 Ratner et al. begin by defining a static bond percolation theory in a system of 1 spatial dimension, with an immobile lattice and spaces in the lattice which may or may not contain particles.11 There is said to be a “bond” between any two sites in the lattice with a traversable path between them, and the bond is “filled” if a particle is present in one of the sites and can traverse the path. The transport of ions can be described in this system by first defining P(t) the probability of a particle being at a given site i per unit time, t.11 A related quantity is defined which describes the probability of a particle traveling from site i to an adjacent site j : this is wi→j.11 From here diffusive behavior can be derived from a differential equation which relates the evolution of probability with time to a sum of probabilities across the full lattice: 𝑑𝑃 𝑑𝑡 (𝑡) = ∑𝑗≠𝑖{𝑃𝑗 (𝑡)𝑤𝑗→𝑖 − 𝑃𝑖 (𝑡)𝑤𝑖→𝑗 } (eq. 4) A variety of individual restrictions apply to the migration probabilities which are explained in detail in the paper. However we can generalize that in cases where sites i and j are unconnected, or a lattice element or particle prevents migration, w is set to zero.11 A similar, but more general model, known as the Dynamically Disordered Hopping (DDH) model was also derived in which some of the conditions for hopping are relaxed, the most notable of these being the condition that hopping only occur between a site and its nearest neighbor.12 5 The key feature of the DBP and DDH models, is that the lattice is not static, but rather bonds i→j may open and close via time dependent changes in the lattice configuration. Ratner et al. therefore define a renewal time τren after which the bonds in the lattice are randomly assigned to be open or closed.11 In their seminal paper on the model, Ratner et al. devised simulations of a one dimensional system and reported that for running times greater than τren diffusive behavior was observed. In a one dimensional system the coefficient of diffusion, D, is related to the ensemble average of the squared distance traveled by a particle, over the renewal time, such that D=/τren .11 After the initial formulation of the DBP and DDH models modifications and expansions were proposed in order to make the theories more applicable to real systems. This included developing a frequency dependent formalism, which is important because of the prevalence of electrochemical impedance spectroscopy, which utilizes an AC potential in the analysis of polymer electrolytes.12 Additionally, the idea of τren was further developed.13,15 Because dynamic movements in a polymer host are thermal in nature, it was proposed that τren is temperature dependant.13,15 A complementary approach to the theoretical methods of Ratner et al. for gaining mechanistic insight into diffusive phenomena in lithium electrolytes, is the use of molecular dynamics (MD) simulations. MD simulations have been used extensively in understanding the microscopic dynamic behaviors of polymers generally, and this work has been the topic of at least one review.16 In the field of polymer electrolytes, Grant Smith, Oleg Borodin, and coworkers have published a series of papers which bring significant new insight.17-21 The work of these authors was not the first attempt to apply molecular dynamics to the diffusive behavior of ions in a polymer matrix. They are notable, however, in their attention to detail in designing a 6 polarizable force field, capable of reproducing experimental diffusion measurements in models of lithium tetrafluoroborate (LiBF4) doped PEO.17,18 Further studies focused on lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) doped PEO.19-21 The PEO/LiTFSI system utilized PEO chains in the Rouse dynamic regime (which governs relatively short, unentangled polymers) with 54 repeating units (2380g/mol) at temperatures ranging from 333 K to 423 K and salt concentrations ranging from 39 – 7.5 ethylene oxide units per lithium ion.19 The results were shown to be in good agreement with experimental measures, both from diffusion NMR measurements, and structural characteristics.19 Lithium ions in the simulations were shown to have an average of 4.6 coordinating oxygens in their first solvent shell, which was in good agreement with the 4.9 oxygen average found using neutron diffraction.19 Additionally degree of dissociation was compared to inferred dissociation from Raman data, and found to be in good agreement; degree of dissociation ranged from 0.95 (95% free ions) to 0.77, and was negatively correlated with concentration.19 Molecular dynamics simulations give detailed information about the movement of particles in a system, so coefficients of diffusion can be calculated from the Einstein equation such that 𝐷 = lim 𝑡→∞ 〈𝑀𝑆𝐷(𝑡)〉 (eq. 5) 6𝑡 Where MSD(t) is the mean square displacement of a particle as a function of time.19 Smith and Borodin then determined temperature dependent coefficients for the polymer host by scaling the time domain obtained at 423K by a “temperature-dependent time-shift factor” such that D(T)=D(423K)/a(T).19 This was done because of the excessive simulation time demands involved in observing true diffusion at lower temperatures for a host polymer of this size.19 7 Once the simulations were shown to conform to experimental results, analyses of the transport of TFSI(-) and Li(+) were conducted based on the observed trajectories. In contrast to previous theory, two separate kinds of motion were found to contribute to the overall coefficient of diffusion for the lithium ion.19 The first motion was a chain to chain transfer, which the authors considered comparable to the “hops” described in dynamic bond percolation, while a second type of diffusive motion consisted of diffusion of the lithium along the polymer chain.19 Additionally it was found that lithium ions could be grouped by mobility; lithium ions which had undergone a chain to chain transfer event generally were more mobile than ions which had remained complexed with a single polymer chain, while ions in complex with two separate chains were the least mobile.19 A microscopic model of lithium ion transport was formulated using the two different transport processes observed and the Monte Carlo algorithm for simulating movement.19 This simplified simulation was able to reproduce results from the initial runs.19 Figure 2 - Rouse theory describes a polymer chain as a series of balls connected by springs.A hypothetical Rouse chain contains NR segments of 1 bead and 1 spring; beads have a designation l which starts at 0 such that l = NR at the end of the chain. The end to end distance vector of the chain is R, and the mean square length of a segment is aR, such that a Gaussian distribution of segment lengths exist in the chain (length variability not represented above).22 8 The model proposed by Borodin and Smith was an improvement on standard dynamic bond percolation, but it still did not explicitly incorporate any physical theories of polymer dynamics. In order to address this omission Maitra and Heuer revisited the simulations and proposed a microscopic theory of lithium transport using the formalisms of Rouse theory.22,23 Rouse theory is a model of polymer chain dynamics, in which molecular details of the chain are absent, and the chain is instead modeled as a series of beads connected by springs.22 Each bead and the spring connected to it make a Rouse segment, such that NR Rouse segments exist in the chain.22 When a polymer of know composition is modeled using this formalism, NR will generally be less than the number of monomer units in the chain, and as such, Rouse theory is not useful for describing movements at the level of conformational changes, and can only be applied in order to model large scale coiling behavior.22 At any point there will exist a vector R representing the distance from one end of the chain to another, and a mean square distance, aR, defines the length of a Rouse segment (see figure 2). The velocity (drl/dt) of each bead (designated l ) can then be written as a differential equation with a term for friction, ζR, and forces originating from the nearest neighbor beads being given by a term deriving from spring mechanics 3kbT/aR2, and the displacement vectors of the beads, such that the form of the equation is 𝜁R 𝑑𝒓𝑙 𝑑𝑡 = 3𝑘𝐵 𝑇 2 𝑎R (𝒓𝑙+1 − 𝒓𝑙 ) + 3𝑘𝐵 𝑇 2 𝑎R (𝒓𝑙−1 − 𝒓𝑙 ) (eq. 6) As such this is a description of velocity that derives from a restoring force that a bead feels when the displacements r-r between the bead and its neighbor differ from the equilibrium distance aR2.22 9 Figure 3 – Three mechanisms (M) and times (τ) are associated with lithium ion transport Rouse model adapted theory of Maitra and Heuer. Lithium diffusion parallel to a chain, chain relaxation, and chain to chain transfer.23 There will be one such equation for each segment in the model, and solving the set of equations leads to a set of eigenvalues known as the rouse modes, which describe the motions of the polymer chain. The lowest order mode designated mode 0 describes translational motion of the polymer, and as the mode number increases the motions described become increasingly more localized, such that most of the motion occurs in the lower order modes.22 Maitra et al. approached the problem by first defining three mechanisms for transport in polymer hosts. Mechanism 1 (M1) is defined as the motion of lithium ions along polymer chains, mechanism 2 (M2) is Rouse mediated diffusion, not including displacement of the lithium ion as a result of translational motion of the polymer, and M3 is transfer of a lithium ion from one chain to another (see figure 3).23 Each mechanism has an associated time τ1, τ2, and τ3 so lithium diffusion DLi can be written as a function DLi= Dc.m.+ DM(τ1, τ2, τ3) where Dc.m. is lithium ion transport mediated by diffusion of the ion in concert with the polymer chain such that the center of mass of the chain is displaced (i.e. movement arising from Rouse mode 0).23 The times τ1 and 10 τ3 are relatively straightforward to understand, but τ2 is related to a quantity τR which is the Rouse time or relaxation time of the polymer chain. This is the time associated with relaxation; the process where the initial end to end distance of the polymer, R0, approaches its equilibrium value Re. Rouse time τR is a property of a neat polymer medium, but the presence of complexing ions slows down relaxation, creating a need for a separate value τ2 to describe the equivalent time in a chain with an associated ion.23 The authors then derived approximate analytical expressions for the dependence of DM on the various times associated with each mechanism. The reader is referred to the paper for the full derivation, but it is necessary to clarify that the authors have used 1/τ12= 1/τ1 + 1/τ2 for convenience in the result. It was shown that the result depends on the relative magnitude of the times involved such that 𝑹2𝑒 𝐷𝑀 = 6𝜋 (𝜏 𝐷𝑀 = 1 3 𝜏12 𝑹2𝑒 18𝜏3 ) 1 2 when τ3 << τ12 (eq. 7) when τ3 >> τ12 (eq. 8) In order to make sense of this model and connect it to DBP theory, it should be noted that as the size of the polymer chains of increases (increasing NR) τ12 should increase.23 Furthermore the authors felt that τ3 should be proportional to the τren described in DBP, as they describe a similar process. It is therefore shown that in systems of large polymers DBP can systematically err due to the increasing contribution of diffusion along polymer chains and with the chains as they relax.23 Finally, the authors compared their model with data from simulations similar to those of Borodin et al. and experimental diffusion data from 7Li pulse gradient spin echo experiments, 11 and estimated the dependence of diffusivity on Rouse number NR, which for this study was defined as the number of monomer units. Results are shown in figure 4.23 Figure 4 – The Maitra and Hueur model as compared to experimental data. N denotes the number of rouse segments in the model, while D is the coefficient of diffusion. Experimental data comes from the work of Shi et al.42 DM is the coefficient of diffusion from the three mechanisms discussed above and Dc.m. arises from diffusion of the polymer chain with associated lithium ions. Figure 4 has been reprinted with permission from Maitra, A.; Hueur, A. Phys. Rev. Lett. 2007, 98, 227802. http://journals.aps.org/prl/abstract/10.1103/PhysRevLett.98.227802 Copywrite 2007, American Physical Society. Using this data we can come up with a few generalizations about the low conductivity of dry polymers. Most importantly Maitra et al. show that as NR increases DM stays relatively constant but Dc.m. approaches zero.23 This implies that most of the loss in conductivity between liquids and dry polymers is from Dc.m.. It follows that a liquid component is probably important for all or most electrolyte design. An important limitation to note about this model is that it does not take phenomena such as polymer crystallization or entanglement into account, which could additionally diminish both modes of conductivity, and cause departure from predicted behavior. 12 1.3 Electrolyte Polarization in Lithium Ion Batteries Aside from low conductivity, the next problematic behavior exhibited by polymer electrolytes is anion mediated polarization. As the cations percolate through the polymer matrix, the anions are also free to move, and migrate in the direction of the anode. This movement results in a high concentration of anions near the anode which experience a coulombic attraction to cations moving toward the cathode; hindering their mobility, and leading to a reduction of current density in the outside circuit. Anions are often 5 to 10 times more mobile than the lithium cations in common electrolyte materials.4 The figure of merit used to describe polarization in an electrolyte is the lithium transference number, T+, which is defined by two values of DC current.132 The initial value of DC current, I0, will be high, because it accounts for both anionic and cationic diffusion. The current drops as the electrolyte polarizes, until it reaches an equilibrium value Is, which is considered to be an approximate value of the portion of current due to cation diffusion. Lithium ion transference T+ is computed simply as T+ = Is/I0 and is interpreted to be related to the relative mobilities of the cation relative to the anion.132 When transference is measured experimentally though, these values are not measured directly, but rather calculated from DC conductivity values.132 The reader is referred to the work of Bruce et al. for the details of this experimental setup and calculation.132 Figure 5 illustrates the concept of polarization and its relationship to T+. Literature strategies for improving solid or solid like lithium ion electrolytes typically focus on one or both of these problems, with optimization of the overall carrier mobility being emphasized over selective lithium ion transference. Electrolytes that have value of T+ which approach unity are termed single ion conductors and resist polarization because the only mobile ions in the system are lithium ions, and therefore I0 = Is for these systems. 13 Figure 5 – Lithium ion transference, T+, is a figure of merit describing the relative mobility of the cation and anion. It is defined as the ratio of the initial current which passes through an electrolyte (which drops during discharge) and the current flowing once an equilibrium has been established.4, 132 1.4 Design Strategies for the Improvement of Lithium Ion Electrolyte Performance In attempts to make dry polymer electrolytes which are more conductive than high molecular weight PEG, many polymers have been synthesized and characterized for conductivity.7 These schemes included linear polymers aimed at preventing crystallization, and at improving segmental mobility, and “comb like” polymers with low molecular weight side chains. However dry systems have invariably shown suboptimal conductivity.4,7 Conductivity can be improved through the use of “gel” electrolytes, which are comprised of a porous solid polymer membrane which has been swelled by an organic solvent.7 Gel like systems can be as conductive as liquids, as the conductivity is mediated by the solvent, rather than the motion of the polymer chains. However they may lose of mechanical stability, as well as electrochemical stability, due to the reactivity of the solvent toward the anode.6,7 A third class of materials has been assembled in an attempt to improve the conductive properties of polymer electrolytes by blending them with inorganic filler materials. In the late 14 1990s Scrosati and coworkers reported a composite of PEG with TiO2 nanoparticles, which they showed to enhance the mechanical strength of the material, as well as the interfacial stability with a lithium electrode.26 These materials were later shown to have the effect of reducing crystallinity in the electrolyte, by providing so many nucleation centers for the formation of crystals that the formation of a lattice is actually impeded by the competing affects.1,4,7,26 A similar approach was employed by the Baker group during this time period. A low molecular weight PEG dimethyl ether, which is a highly conductive liquid, was used as a conductive media.27,28 Mechanical support was provided by a variety of surface functionalized fumed silica particles (fig.4), which could be dispersed in the PEG and cured using a UV crosslinking reaction. These electrolyte systems showed improved mechanical strength, and conductivities in the range of 10-4 – 10-3 S/cm.27,28 A more recent approach involves the direct functionalization of silica or zirconia nanoparticles with a conductive medium, of either PEG or ionic liquid derivation.8,29,30 PEG derivatives were bound directly to the nanoparticles, using either a covalent silicate linkage, or acid base chemistry between amine functionalized particles, and sulfonic acid functionalized PEG chains.24 PEG functionalized particles were doped with 1M lithium Bis(trifluoromethane)sulfonimide (TFSI), and showed molecular weight dependant conductivity, which was above 10-4 S/cm for some materials.24 Additionally, silicate functionalized particles with a corona of 400 molecular weight PEG (fig.4) were blended with poly(ethylene glycol) dimethyl ether 250 (PEGDME250) a short polyethylene glycol chain terminated with a methyl ether at each end. This improved the conductivity of the system over that of the solvent free particles.30 It was shown that the onset of solid like behavior occurs in the PEGDME at a composition of roughly 38% particles (v/v), at which point the system has a conductivity of 15 nearly 10-3 S/cm.30 While the ionic liquid functionalized particle is an intriguing idea, this system had lower performance at room temperature; on the order of 10-5 to 10-6 S/cm.29 Figure 6 – Silicate functionalized fillers used in the nanocomposites of the Baker (top) and Archer groups (bottom two). 27,29,30 The problem of lithium transference in polymer electrolytes has also been an area of prolific research, with many of the proposed schemes involving synthetic modifications of PEG derived macromolecules. Published polymeric single ion conductors chiefly employ one of two common strategies to suppress anion movement; Lewis acidic anion receptors can be installed in the polymer, to bind anions after the introduction of a lithium salt,31 or a polyelectrolyte can be synthesized, consisting of polymer bound anions with lithium counter ions.32,33 Mehta, Inoue and colleagues offer a representative example of the anion receptor approach.31 Their material is composed of a blend of PEG mono methyl ether and triethylene glycol which is condensed in the presence of boroxine, to yield a solid material composed of 16 branched PEG chains with Lewis acidic boroxine rings at the branch points. This material is compatible with a variety of common lithium salts, including LiTFSI, LiClO4 and lithium triflate. Transference numbers measured for lithium were in the range of 0.62-0.88 (where a value of unity indicates that all current is a result of lithium transport) which is a significant improvement over the typical values given for PEG of 0.15 – 0.45.31 Single ion conductive systems unfortunately are also subject to problems of low conductivity; values for this system were on the order of 10-5 – 10-7 S/cm.31 Figure 7 – Monomers produced by Kerr et al. (left) produced a crosslinked single ion conducting solid in the presence of a platinum catalyst. Endo et al. produced monomers (right) which could produce the same effect when heated.32,33 A common approach for the production of single ion conductors based on covalently bound anions is the synthesis of alkylated lithium salts, which can then be used to chemically crosslink the conductive material in situ.32,33 The groups of Kerr and Endo have described materials based on schemes such as these, relying on PEG derivatives and hydrosilation, or epoxide ring opening chemistry respectively for crosslinking (fig 5).32,33 17 Ionic liquids have likewise been considered as candidates for high transference electrolytes. Unlike most of the electrolytes previously discussed, ionic liquids are true liquids, but their resistance to flammability, inherent conductivity, and low vapor pressure make them good candidates for electrolyte materials.91 On the other hand, there is no obvious reason that a conventional binary ionic liquid would offer an advantage with respect to Lithium transference. Ohno and coworkers have made several attempts at designing selective lithium conductors based on ionic liquids.123-125 One such attempt involved the use of linked zwitterions blended with lithium TFSI.123 A set of zwitterions were synthesized, each of which contained a cation and anion linked by an alkyl spacer group.123 The cation and anion chemistries were varied in the study, and so was the length of the spacer group. While most of the zwitterions themselves had melting points over 100 °C, it was discovered that some of them could be blended with LiTFSI to make liquids. Unfortunately these liquids suffered from low conductivity and low transference.123 A similar class of materials engineered by this group was composed of triple ions containing two anions and one cation.124,125 The first of these was obtained by reacting imidazoles with two equivalents of 1,3-propanesultone under basic conditions, which led to the formation of imidazolium salts with twin sulfonate groups and an alkali metal counter ion.124 A second class of similar materials was later developed, containing one borate and one sulfonate group on an imidazolium scaffold.125 These classes of materials had lithium transference numbers as high as 0.76. However the general tendency of these materials was to have a high melting (Tm) and glass transition temperature (Tg).124,125 The materials with dual sulfonates were the worst in this regard; they melted above 200 °C and had glass transitions around room temperatures.124 The borate materials improved significantly; they were liquids with Tg as low as 18 -25 °C.125 The highest room temperature conductivity for any of these materials was below 10-7 S/cm, well below what would be useful in application.125 At least one novel approach has sought to avoid the limitations of dynamic percolation altogether. In noting that PEG forms helical structures when crystalline34 Bruce and co-workers authored several remarkable papers in which they sought to tune ionic mobility of lithium ions in crystalline PEG lithium salt complexes.35-37 By crystallizing PEG with several different anions including antimony hexafluoride or tetrafluoroborate it was possible to generate regular structures, in which lithium ions were mobile, and could percolate down the helical channels in the crystal structure of the polymer, with the counter ions trapped in the lattice. Successive attempts were made to raise the room temperature conductivity of this system, which started on the order of 10-7 to 10-8 S/cm, by using doping with different monovalent ions,35 doping with divalent Li2SiF6 in order to increase the number of mobile lithium ions in the channels,36 and using low molecular weight glymes as a host.37 Unfortunately, none of these strategies resulted in a conductivity above 10-5 S/cm at room temperature. 1.5 Strategies of Single Ion Conductor Design from the Baker Research Group Attempts to improve the lithium transference in polymer nanocomposites have been made in the Baker Group starting with the work of Fadi Asfour in the early 2000s.26 This scheme entailed grafting a single layer of trifluorosulfonamide terminated alkyl chains (Fig. 6) which would be deprotonated using butyl lithium to yield nanoparticle localized negative charges, which would then be combined with PEGDME 500 for analyses of conductivity. The particles tested by Fadi had low loadings of lithium, limited by the grafting density of the particles. The lithium to ether oxygen ratios tested were in the range of 1:250 to 1:710, depending on the 19 loading of nanoparticles, which increased to 40% w/w.26 Conductivities observed for this system were on the order of 10-6 S/cm at 30°C. Figure 8 – Nanoparticle designed of Asfour (top), and the most conductive design of Zhao (middle) and an attempt to improve the interfacial properties of synthesized polyelectrolytes (bottom). Polyelectrolytes allow for higher ratios of lithium to oxygen, but have not improved conductive performance to date.4, 26 This work was continued by Hui Zhao, who designed a variety of nanocomposites with many layers of ions, in an attempt to improve on earlier work by increasing the concentration of lithium ions in the electrolye.4 These polymers are comb-like polyelectrolytes based on hydrophobic alkyl chains constructed through radical polymerizations of functionalized styrenes and methacrylates (Fig. 6). Oxygen to Lithium ratio in these experiments was in the range of 1:250 to 1:30, with optimal loading typically occurring in the neighborhood of 1:60. The best system of Zhao’s devising has a measured room temperature conductivity of roughly 10-6 S/cm.4 This result was both surprising and disturbing, as he had increased the lithium ion concentration 20 of the system significantly relative to Asfour’s materials, but the performance he observed was no better. Several hypotheses were considered for why the higher lithium density polymers of Zhao have not outperformed the monolayer particles of Asfour. In considering equation 1, it can be reasoned that if carrier concentration has been increased, while new sets of carrier species have not been introduced by experimental design; a comparable ionic conductivity should therefore reflect an overall loss in the mobility of lithium. The most apparent potential problem of the polyelectrolyte particles that our lab has so far produced is related to solubility. The significantly lipophilic polymethacrylates and polystyrene backbones are being expected to interface with water soluble PEGDME 500. Zhao has attempted to improve the interfacial properties between the PEGDME500 and polyelectrolyte particles in the synthesis of a random copolymer of styrene sulfonate and PEG methacrylate monomers (fig.6). This approach did not significantly improve conductivity in composites.4 An additional consideration for the ionic mobility of a polyelectrolyte is the flexibility of the particle bound chains. While differential scanning calorimetry data have not been published on the polyelectrolyte particles to date, literature values put the Tg of 1 – 4 carbon n-alkyl polymethacrylates in the range of 20 to 100°C43 indicating that a high glass transition may be a problem for these materials. Finally, we considered a problem which might reasonably be described as “micropolarization”; in effect, when the concentration of charge carriers is increased in the composite the new charges are all bound to particles. The particles are then introduced into PEGDME 500 which has no charge carriers. As the lithium cations move under an applied 21 potential, the lithium cation becomes isolated in the PEGDME 500 and a coulombic attraction builds between the negative charge left on the particle and the cation in the PEGDME. Mobile cations must therefore pass from particle to particle, and the conductivity will be inversely proportional to the distance between particles. A suggested fix for this would be the use of an ionic liquid conductive media rather than PEGDME 500. Alternatively, at high concentrations of particles this should become a negligible problem. A solution I proposed for oral exam is shown below; it is composed of a silica nanoparticle functionalized with a brush of alkyne terminated PEG chains (fig. 7). The alkyne termination is intended to make use of the copper catalyzed alkyne azide cycloaddition (CUAAC) “click” reaction, which exhibits excellent yield and conversion, with easily removable side products.44 This allows rapid assembly of a nanoparticulate electrolyte system which was designed to be tunable in lithium content and interfacial properties by “clicking” with alkylated lithium salts of various derivations, chain lengths and lithium contents. Systems like this have been reported previously in the literature,40,41 but, to the best of my knowledge such a scheme has not been previously proposed for use as a lithium electrolyte material. 22 Figure 9 – Proposed fillers for nanocomposite conductors. Clickable Particle 9 can be used to access designs 10 and 23 among others. At the time of my oral however we were unaware of a helpful physical study into the nature of the underlying problems with single ion conductors. This study will be described in the next section. 1.6 Problems with Single Ion Conductors Demonstrated in Experiment and Simulation Problems with single ion conductors have attracted interest from others, and in 2006 a seminal paper was published exploring the fundamental problem with these materials. The paper was a collaboration between the theorists Borodin and Smith, and the research group of Darryl DesMarteau, an experienced fluorine chemist.20 In order to isolate the tethered anion as a variable, the experimentalists compared a system of methyl capped PEO with 12 repeating units (EO12/LiTFSI) with a synthetic analogue composed of a PEO system with a tethered bis(sulfonimide) group closely resembling the TFSI(-) moiety (figure 10) .20 23 Figure 10 – Tethering anions to a host material has a dramatic deleterious effect on the conductivity of single ion conductors.20 Image reprinted with permission from Borodin, O.; Smith, G. D.; Geiculescu, O.; Creager, S. E.; Hallac, B.; DesMarteau, D. J. Phys. Chem. B 2006, 110, 24266 – 24274. Copywrite 2006, American Chemical Society. Measurements done by the experimental part of the group provide a powerful demonstration of the problems inherent in polymer single ion conductors. The data shown in fig. 10 indicates that at 294 K (21 °C) conductivity drops from roughly 10-3 S/cm (binary) to roughly 10-6 S/cm (tethered) or three orders of magnitude.20 This data puts the work of Zhao and Asfour in a new light, as it demonstrates that the concerns about phase separation and Tg of particle 24 grafted polymers are probably not necessary to explain the low conductivity observed, because neither would have been a factor in the work of DesMarteu et al. Borodin et al. used this data as a benchmark for their MD simulations.20 The close agreement between the experimental and simulated results lends credibility to insights drawn from the simulated systems. The authors looked at mechanisms similar to those described in the Rouse based model of lithium ion transport detailed above. The authors mainly discussed conductivity resulting from diffusion of a lithium ion with an associated chain, and conductivity resulting from migration of a lithium between chains; to use the formalism developed later by Maitra et al., the first of these would be Dc.m..20,23 When considering the contribution of DM, Borodin et al. explicitly consider the effect of M3 (interchain transfer) and neglect M1, and M2.20,23 This is a defensible omission, as the contribution of these mechanisms should be negligible for systems composed of short chains which should be governed by the dependence described by equation 8.23 The most important difference between a tethered system and a binary system relates to the nature of Dc.m. in these systems.20,23 Classical conductivity described by the Nernst/Einstein equation (eq. 2) either assumes full dissociation (i. e. independent movement) of cations and anions in the system, or explicitly includes a term, α, to describe the ratio of ions which are diffusing independently of a counter ion.20 In a binary system this term is independent of Dc.m. as a lithium ion may diffuse with a chain whether or not an anion is also associated.20 When the anion is connected to the chain however, Dc.m. describes the diffusion of an associated ion pair by definition, and does not contribute to the conductivity of an electrolyte unless multiple cations are bound to the chain.20 This problem was evident in the α values reported for the two 25 electrolytes at 294 K, whereas the value in the binary electrolyte was 0.9, the tethered electrolyte had an α value of 0.5.20 This change causes the conductivity to be more dependant on the rate of interchain transfer events in the electrolyte with a tethered anion.20 Unfortunately, chain to chain transfer is also retarded by the presence of an anionic head group on the chain.20 The reported Li(+)-chain residence time ( analogous to the τ3 of Maitra et al.) was over twice as long for the tethered system as it was for the binary system (~40 ns to ~90 ns) at ~90 °C.20 1.7 On the Construction of Lithium Single Ion Conductors and the Making of Lemonade A critical reading of the literature on single ion conductors might seem like a hopeless litany of failure, but this is not necessarily the case. While there is unlikely to be an organically based lithium single ion conductor which is itself useful as an electrolyte, single ion conductors such as the ones produced by DesMarteau or Ohno might be a useful additive to binary electrolytes in order to reduce polarization without completely sacrificing conductivity. On the other hand, research strategies that require difficult synthesis of elaborate materials are probably a misguided way to approach the single ion conductor problem. Many papers in the materials literature describe complicated materials designed to be applicable, rather than simple materials designed to test a hypothesis. If no clear hypothesis is being tested, disappointing results equate to wasted time, as it becomes difficult to draw conclusions from the data. In this regard the work of DesMarteau and Borodin et al. is inspiring; regardless of whether the single ion conductor they report is useful for application, the results are clearly interpretable because of good study design, adequate controls, and the attention paid to rigorous mechanistic interpretation of the results. 26 This change in thinking is the main reason why the synthesis and characterization of the materials in figure 9 will not be reported in this work. Too many variables exist in such systems to be adequately controlled for, and the synthesis of particle 9 is a difficult six step process with two steps related to nanoparticle functionalization that are difficult to do reproducibly. Further, functionalized nanoparticles produced from orthosilicate materials such as 3aminopropyltriethoxysilane (APTES) and its derivatives are chemically ill-defined due to variables in functionalization density and oligomer formation. Finally, the work of DesMarteau and Borodin et al. make the success of ionomer grafted nanoparticle designs of the sort that we were considering seem unlikely. While work in the style of Zhao and Asfour has been abandoned, the use of the CUAAC reaction to construct lithium ion electrolytes is still an intriguing and untested idea. The CUAAC reaction accomplishes a coupling by forming a triazole from alkyne and azide precursors. However triazoles are not a common feature of lithium ion elecrolytes. Professor Baker was interested in potential effects of triazoles on conductivity as an unintended consequence of introducing them into the electrolytes, and encouraged Zhao to investigate this problem.126 Zhao synthesized a series of polymer containing triazoles with molecular weights of roughly 104 g/mol and showed that at 90 °C their salt composites had conductivity similar to that of PEG of a similar molecular weight.126 A study which controls for dispersity, and analyzes this finding can be found in chapter 2 of this document. A second focus was the pursuit of a single ion conductor material to improve the chain to chain transfer time of lithium ions. A class of triple ions similar to those of Ohno et al. was initially proposed for this, partially owing to the fact that we were not aware of their work, and did not expect the high Tm and Tg and low conductivity that they observed.124,125 27 Figure 11 – Ohno-like triple ions proposed as novel single ion conductors. Synthesis of the triple ions shown in figure 11 proved to be a significant challenge and several different routes were attempted in the process (figure 12). In one of the routes attempted, an analogue of 1,3-propanesultone which we called N-triflylpropanesultam (TPS) was used as a precursor to the triple ion. A synthesis of TPS was devised and successfully executed, but the difficulties of obtaining pure samples of triple ions, and the discovery of Ohno’s work led to the abandonment of the triple ion project. Instead attempts were made to map the reactivity of TPS and establish whether it could be a useful material for producing alkylated TFSI-like anions. Initial expectations were that TPS would be a highly reactive material given that it contained a nitrogen leaving group which had two sulfonyl groups and ring strain activating it. Preliminary exploration in the beginning of the triple ion project had suggested that alkylated TFSI materials were very powerful alkylating agents. Several experiments were done in which amines were quaternized with these materials in good yield with modest reaction times. However 28 TPS had to be boiled with an amine for days in order to react, and it often gave significant amounts of side products resulting from nucleophilic attack at sulfur. Figure 12 – Three attempts to synthesize triple ions. The last of these featured TPS, a previously unknown molecule whose reactivity was much less pronounced than expected, sparked interest in the nucleofugality of polyatomic anionic nitrogen nucleofuges. While the reactivity of TPS did not appear to be promising, the surprise of its relative inertness seemed worth investigating. Computational studies were initiated which analyzed Menshutkin reactions of polyatomic anionic leaving groups of nitrogen and oxygen in order to better understand why TPS had been less reactive than expected. While the proceedings of this study are probably of limited use to the materials chemistry community, there is ongoing 29 discussion in the physical chemistry literature about the precise nature of nucleofugalty (leaving group ability) which would benefit from this research. This research appears in its entirety in chapter 3 of this document. 30 2 2.1 Chapter 2: 1,2,3-Triazoles as Pseudo-Ether Moieties in Oligo (Ethylene Glycol) Based Lithium Ion Electrolytes Introduction As the average global temperature continues to rise, the importance of finding novel, clean strategies for generating and storing energy continues to be an imperative for scientists and engineers. Lithium ion batteries were first demonstrated in the 1976,42 and research into cathode, anode and electrolyte materials for lithium ion batteries continues to be avidly pursued today. Polymer electrolytes were developed contemporaneously with lithium battery technologies, however the conductivity of polymer electrolytes are often too low for use in lithium batteries. In the interest of raising the conductivity of dry polymer electrolytes, many different host polymers including polyethers, polysiloxanes, polyphosphazines, and architectures including comb polymers and nanoparticle composites have been tried.7 Additionally, physical studies have been performed and models proposed in order to rationalize lithium ion transport dynamics in a polymer host.5,9 Among these models, one of the most prominent is the dynamic bond percolation theory (DBP) of Ratner et al.11-15 DBP is formulated in terms of a renewal time τ in which one path between coordination sites has opened and closed to each lithium ion in a system. The conductivity of a system depends on the renewal time and therefore has been found to depend on polymer segmental dynamics generally and the glass transition temperature (Tg) specifically.15 Additional studies have utilized ab-initio calculations to show that glyme-derived complexes with divergent geometries have similar energies within the same coordination number, at coordination numbers of 4, 5 and 6 ether oxygens around lithium.43 A recently developing trend in polymer chemistry has been the application of click chemistry; a set of reliably working, high efficiency reactions originally promoted for rapid 31 construction of complexity in drug discovery,39 which have been adopted by materials chemists for such tasks as post synthetic modifications of polymers and surface functionalization of nanoparticles, and the construction of dentrimers.44,45 One of the most common of these socalled “click” reactions is the copper catalyzed alkyne azide cycloaddition reaction (CuAAC) or Huisgen reaction used to couple materials through the formation of a distinctive 1,2,3- triazole motif.39 The 1,2,3-triazole species has been used in the manipulation of ionic species previously in the design of anion receptors46 and occasionally proton conductors,47-49 however these heterocycles have been use in only one lithium conductor that we are aware of.50 The decision by the materials community to eschew the use of the CuAAC reaction in the development of lithium ion conductors may have its roots in concerns about the effect of the 1,2,3-triazole moiety formed in the reaction on the conductivity of the electrolyte. Deleterious effects of on conductivity might reasonably include a net stiffening of the polymer material and associated increase in the Tg,15 a decrease in lithium ion mobility due to a higher energy association between the lithium cation and the triazole ring, or a loss of solubility of lithium due to unfavorable association.43 Lithium ion affinities of various nitrogen heterocycles including 2H-1,2,3-triazole, 1-H-1,2,4-triazole and various other azoles and azines have been measured using collision induced dissociation mass spectrometry, and calculated at various levels of theory, by Rodgers and co-workers.51-54 These affinities typically exceed those measured and calculated for dimethyl ether using the same methods (Fig. 14), making loss of solubility of lithium salts seem unrealistic, but strong complex formation with lithium potentially problematic.43 32 Scheme 1 – Model compounds with whole number triazole to ether oxygen ratios. Each has a name derived from the number of ether oxygens and triazoles in the compound, hence “8 ether oxygens, 2 triazoles” becomes “8EO2T”. In order to investigate the effect of 1,2,3-triazole moieties on the conductivity of lithium ion transporting polymers, we report a study on a series of monodisperse oligomer model compounds (Scheme 1) with increasing 1,2,3-triazole to ether oxygen ratios. In order to build on the work of Rodgers et al. we model hypothetical solvation shells for lithium ions using high level ab initio calculations. Additionally we have synthesized the model compounds and measured the conductivity of oligomer salt complexes using AC impedance spectroscopy. 33 Calculations and empirical modeling of the conductivity enable us to pinpoint dynamic effects brought on by introduction of the stiff triazole moieties into the chain as the chief reason for depressed conductivity in the model compounds. 2.2 Experimental 2.2.1 Computational methods All calculations were initiated on the Cambridge Software Chem3D interface for General Atomic and Molecular Electronic Structure System55 (GAMESS) in order to find coordinates for the model compounds. Our main calculation for smaller models was the MP2(full)/Aug-ccpVTZ(Li-C)//MP2(full)/cc-pVDZ(Li-C) composite method previously reported by Rodgers et al.51 This calculation was one of the best performers in a study conducted by these authors which included high quality methods such as coupled cluster methods, complete basis set extrapolation, and the Gaussian theory methods of Pople et al.51 Our models were typically run at the HF/3-21G level of theory prior to the application of higher levels of theory, and in the case of 2, 3 and 4 coordinate models the complexes were manipulated manually in the Chem3D interface to get the highest number of ligations possible and minimized using the MM2 force field prior to minimization at HF/3-21G. Pre-optimization calculations were run on a laptop. Starting points from HF/3-21G, were then optimized using three composite methods: MP2(full)/Aug-cc-pVTZ(Li-C)//MP2(full)/cc-pVDZ(Li-C),51 Gaussian 3 (G3),56 or G3(MP2)57 using the Gaussian 03 computational package.58 The Aug-ccpVTZ(Li-C) and cc-pVDZ(Li-C) basis sets reported by Rodgers et al. were generated by obtaining cc-pCVDZ and Aug-cc-pCVTZ basis sets59 for lithium from EMSL Basis Set 34 Exchange,60, 61 and applying them to the Li ion, while the other atoms received the parent ccpVDZ or Aug-cc-pVTZ basis set. This allocation was accomplished in Gaussian 03 through use of the Gen keyword. Association energies (ΔEass) were calculated by comparison of the minimized ligand to the complex and lithium ion such that ΔEass = Ecomplex - Eligand -ELi (eq. 9) Zero point energy corrections were applied from the MP2(full)/cc-pVDZ(Li-C) level of theory and scaled by a factor of 0.9646.51 The reader is referred to the original paper for additional details on the MP2(full)/Aug-cc-pVTZ(Li-C)//MP2(full)/cc-pVDZ(Li-C) calculation.51 G3 and G3(MP2) were used as implemented in Gaussian 03. All Gaussian 03 calculations were run on the MSU Chemistry Department hydra cluster. 2.2.2 Electrochemical Impedance Spectroscopy All impedance spectroscopy was done on an HP4192A LF impedance analyzer setup which has been fed into a Vacuum Atmospheres Dri-Train M040-1 model glove box with a nitrogen atmosphere. Model compounds were rigorously dried in preparation for conductivity measurements by stirring on a mass equivalent of 4 Å molecular sieves in dry ethyl ether or dichloromethane. Following this the compounds were filtered and solvent was removed on a standard rotovap connected to a vacuum aspirator. Finally, model compounds were placed on a Schlenk line and heated to 70°C. The line was allowed to equilibrate to a pressure of < 100mTorr which was sustained for at least 24 hours. Inhibitors were removed from PEG500 DME prior to drying, by elution through a flash column with a dry ethyl ether mobile phase. All samples were then inserted and stored in the glove box. Samples were prepared by addition of LiTFSI or LiClO4 to the electrolyte media, followed by stirring until the salt composite became 35 homogenous. The amount of salt added was normalized to the number of ligand atoms in the PEG 500 DME or model compound, such that a triazole was considered to have two ligand atoms, and PEG 500 DME was considered to contain 12 ligand atoms on average. Samples were loaded into a homemade coin cell with stainless steel blocking electrodes, and clamped together with leads from the impedance analyzer in a homemade temperature controlled bell jar. Measurements were taken from 30°C - 85°C, using a virtual instrument code written for Labview 5. Temperature control was adjusted manually, and is estimated to have a precision of +/- 1°C. 2.2.3 Single Crystal X-Ray Diffraction Single crystals of 6EO2T (C9H16N3O3) were crystallized from toluene. A suitable crystal was selected and mounted on a nylon loop using Paratone Oil. The crystal was kept at 173.01 K during data collection. Data were collected using a Bruker APEX-II CCD (charge coupled device) based diffractometer equipped with an Oxford Cryostream low-temperature apparatus operating at 173 K. Data were measured using omega and phi scans of 0.5°per frame for 30 s. The total number of images was based on results from the program COSMO,74 where redundancy was expected to be 4.0 and completeness to 0.83 Å to 100%. Cell parameters were retrieved using APEX II software75 and refined using SAINT on all observed reflections. Data reduction was performed using the SAINT software76 which corrects for Lp. Scaling and absorption corrections were applied using SADABS77 multi-scan technique, supplied by George Sheldrick. Using Olex2,77 the structure was solved with the XS 78 structure solution program using Direct Methods and refined with the XL 79 refinement package using Least Squares minimisation. 36 The structure was solved in the space group C2/c (no. 15). All non-hydrogen atoms are refined anisotropically. Hydrogens were calculated by geometrical methods and refined as a riding model. 37 2.2.4 Synthesis of Model Compounds Scheme 2 - Synthesis of triazole containing poly(ethylene glycol) based model oligomers 38 2.2.4.1 Materials and Instrumentation Starting materials were procured and used as obtained from commercial suppliers including Sigma-Aldrich, Alfa Aesir and Jade Scientific. NMR spectra were obtained using Varian 500 MHz and 300 MHz instruments in the MSU NMR facility, all NMR specra were run in CDCl3. IR Spectra were obtained using a Mattson Galaxy FTIR spectrometer. High resolution mass spectrometry was performed by the MSU Mass Spectrometry Core using a Micromass QTOF Ultima instrument. Phase and glass transitions of the model compounds were measured using the TA Q2000 Differential Scanning Calorimeter in the Composite Materials and Structures Center at MSU College of Engineering. 2.2.4.2 Synthesis of Tosylates 1 – 5. Method 162 Methoxy oligo(ethylene glycol) precursors and p-toluenesulfonylchloride (1.02 equiv. per hydroxyl) were added to flask equipped with a mechanical stirring apparatus, and charged with CH2Cl2 on ice, such that the concentration of the oligo(ethylene glycol) species was approximately 0.95 M. Potassium hydroxide was then measured (4 equiv. per hydroxyl) and added without crushing in portions over a one hour period. After the addition of the potassium hydroxide pellets was complete, the ice bath was allowed to melt and warm to room temperature. Stirring was allowed to continue for 24 hours. Reaction was quenched by the slow addition of water until water soluble salts were dissolved. The layers were then separated, and the aqueous layer extracted with two additional portions of CH2Cl2. The combined organic layer was dried over sodium sulfate and solvent was removed on a Rotovap, followed by a hard vacuum. The products were used without further purification. 39 Method 263 A tetrahydrofuran solution of the methoxy oligo(ethylene glycol) solution of roughly 0.75 M concentration was prepared in a round bottom flask with magnetic stirring. To this solution 1.5 equiv. of p-toluenesulfonyl chloride were added, and the flask was chilled on ice. To the cooled flask a 16 M solution of potassium hydroxide (6.5 equiv. per hydroxyl group) in water were added in parts over roughly 1 hour. Following addition of the potassium hydroxide, the ice bath was removed. The reaction was then allowed to stir roughly 12 hours at room temperature. The reaction was subsequently quenched by addition of the reaction mixture to 5 mL ice per mL of the mixture and extracted with 3 portions of CH2Cl2. Drying and solvent removal proceeded as in method 1. Product was used without further purification. This method was used for compound 4 only and was discontinued due to poor yield. 2-methoxyethyl 4-methylbenzenesulfonate (1) 92% 1H NMR (500 MHz) (CDCl3) δ: 2.42 (s, 3H, CH3O) 3.28 (s, 3H, Tosyl-CH3) 3.55 (dd, 2H, CH3OCH2, J= 5 Hz, J= 5 Hz) 4.13 (dd, 2H, TsOCH2, J= 5 Hz, J= 5 Hz) 7.31 (d, 2H, CH3CCHCHCSO3, J = 8 Hz) 7.77 (d, 2H, CH3CCHCHCSO3, J = 8 Hz) 13C NMR (500 MHz) (CDCl3) δ: 21.82, 59.17, 69.25, 70.13, 128.16, 129.99, 133.25, 144.96 2-(2-methoxyethoxy)ethyl 4-methylbenzenesulfonate (2) 93% 1H NMR (500 MHz) (CDCl3) δ: 2.41 (s, 3H, CH3O) 3.31 (s, 3H, Tosyl-CH3) 3.45 (m, 2H, CH3OCH2) 3.53 (m, 2H, CH3OCH2CH2) 3.65 (m, 2H, TsOCH2CH2) 4.13 (m, 2H, TsOCH2) 7.30 (d, 2H, CH3CCHCHCSO3, J = 8 Hz) 7.76 (d, 2H, CH3CCHCHCSO3, J = 8 Hz) 13C NMR (600 MHz) (CDCl3) δ: 21.79, 59.20, 68.88, 69.40, 70.85, 71.99, 128.16, 129.98, 133.19, 144.97 40 2-(2-(2-methoxyethoxy)ethoxy)ethyl 4-methylbenzenesulfonate (3) 91% 1H NMR (500 MHz) (CDCl3) δ: 2.41 (s, 3H, CH3O) 3.31 (s, 3H, Tosyl-CH3) 3.49 (m, 2H, CH3OCH2) 3.57 (m, 6H, OCH2CH2O) 3.64 (t, 2H, TsOCH2CH2, J= 5 Hz ) 4.12 (t, 2H, TsOCH2, J= 5 Hz ) 7.30 (d, 2H, CH3CCHCHCSO3, J = 8 Hz) 7.75 (d, 2H, CH3CCHCHCSO3, J = 8 Hz) 13C NMR (500 MHz) (CDCl3) δ: 21.76, 59.15, 68.82, 69.39, 70.69, 70.71, 70.89, 72.06, 128.11, 129.96, 133.23, 144.92 2,5,8,11-tetraoxatridecan-13-yl 4-methylbenzenesulfonate (4) 66% 1H NMR (500 MHz) (CDCl3) δ: 2.41, (s, 3H, CH3O) 3.33 (m, 3H, Tosyl-CH3) 3.50 (m, 2H, CH3OCH2) 3.54 (m, 4H, OCH2CH2O) 3.60 (m, 6H, OCH2CH2O) 3.65 (m, 2H, TsOCH2CH2) 4.13 (m, 2H, TsOCH2) 7.30 (d, 2H, CH3CCHCHCSO3) 7.75 (m, 2H, CH3CCHCHCSO3) 13C NMR (500 MHz) (CDCl3) δ: 21.79, 59.17, 68.81, 69.40, 70.67, 70.73, 70.74, 70.88, 72.07, 128.12, 129.97, 133.14, 144.95 (ethane-1,2-diylbis(oxy))bis(ethane-2,1-diyl) bis(4-methylbenzenesulfonate) (5) 81% 1H NMR (500 MHz) (CDCl3) δ: 2.43 (s, 6H, Tosyl-CH3) 3.50 (s, 4H, OCH2CH2O) 3.63 (dd, 4H, TsOCH2CH2O, J = 5 Hz J = 5 Hz ) 4.12 (dd, 4H, TsOCH2CH2O, J= 5 Hz J=5 Hz ) 7.33 (d, 4H, CH3CCHCHCSO3, J = 8 Hz) 7.77 (d, 4H, CH3CCHCHCSO3, J = 8 Hz) 13C NMR (500Hz) (CDCl3) δ: 21.27, 68.79, 69.37, 70.73, 128.026, 129.97, 132.97, 145.01 2.2.4.3 Synthesis of Azides 6 – 8 A flask was set up with a condenser magnetic stir bar, and charged with DMF, and a tosylate precursor (3 – 5). Two equiv. sodium azide were then added such that 0.44 mol of sodium azide were added per liter of DMF (note: sodium azide did not fully dissolve, and some amount of precipitate persisted throughout reaction, intensifying as TsONa is produced). DMF solution was heated to 70°C and allowed to react overnight or roughly 12 hours. DMF was 41 removed directly by distillation under reduced pressure. Concentrated reaction mixture and solids were dissolved into 1 portion water and 1 portion diethyl ether. The layers were separated and the water was washed with two additional portions of diethyl ether. The ether layer was combined and dried over sodium sulfate and concentrated on a rotovap and a vacuum line. Azides (especially 8) may be volatile enough that extended use of a vacuum pump will reduce yield considerably. Residual DMF was removed by flash chromatography on a silica mobile phase with diethyl ether eluent, followed by reconcentration. WARNING: The synthesis and concentration of organic azides is an especially hazardous procedure. Concentrated azides may detonate in contact with heat, reactive chemical species or mechanical stimulation. Sodium azide can react to form extremely unstable compounds if exposed to chlorinated solvents (including but not limited to dichloromethane and chloroform) or transition metals. None of the azides described in this paper have caused the authors problems, but scaling these procedures should not be done by anyone not experienced in the synthesis of azides or related compounds. The authors, furthermore, make no representation that synthesis on the scale done by the authors is safe for other chemists to attempt. Azides must be diluted in solvent before catalyst is introduced in the CuAAC reaction, or potentially fatal explosions can result. Azides were stored under nitrogen gas, and protected from light in a -20°C freezer. Special caution should be used in the making and handling of compound 8. 1-azido-2-(2-(2-methoxyethoxy)ethoxy)ethane (6) 65% 1H NMR (500 MHz) (CDCl3) δ: 3.34 (m, 5H) 3.51 (m, 2H, CH3OCH2) 3.63 (m, 8H) 13C NMR (500Hz) (CDCl3) δ: 50.85, 59.15, 70.17, 70.76, 70.82, 70.86, 72.09 42 13-azido-2,5,8,11-tetraoxatridecane (7) 93% (500 MHz) (CDCl3) δ: 3.33 (m, 5H) 3.50 (m, 2H, CH3OCH2) 3.63 (m, 12H) 13C NMR (500Hz) (CDCl3) δ: 50.79, 59.15, 70.14, 70.63, 70.73, 70.75, 70.77, 70.80, 72.05 1,2-bis(2-azidoethoxy)ethane (8) 91% 1H NMR (500 MHz) (CDCl3) δ: 3.36 (t, 4H, N3CH2, J = 5 Hz) 3.65 (m, 8H) 13C NMR (500Hz) (CDCl3) δ: 50.87, 70.31, 70.9 2.2.4.4 Synthesis of Alkynes 9 – 11 Tosylate precursor (1 – 3) was diluted in THF to a concentration of 0.5 M and chilled on ice in a flask with magnetic stirring. In a separate flask a 1.2 M solution of propargyl alcohol (5 equiv. per tosyl ester) was made in THF and chilled on an ice bath. NaH (60% dispersion in mineral oil, 2 equiv. per tosyl ester) was measured, and washed twice with hexane in order to remove the mineral oil. After two washes, the NaH hexane slurry was added to the propargyl alcohol, and the deprotonation was monitored visually by the release of hydrogen. NaH was added at a slow enough rate that the bubbling was steady but not overly rapid. Bubbling was allowed to subside completely, and solution was observed to clear. The partially deprotonated propargyl alcohol solution was then carefully but rapidly poured into the tosylate solution, which was kept on ice until the addition was complete. The reaction flask was allowed to stir on ice roughly 20 min longer, after which time the ice was removed and the flask was stirred for 16 – 24 hours longer. All portions of this reaction were carried out under nitrogen. Reaction was quenched by addition of water until all solids are dissolved, followed by rotary evaporation to remove most of the THF. The resulting aqueous layer was extracted three times with dichloromethane. The combined organic layer was then dried over sodium sulfate and evaporated. Alkyne products were purified by distillation under reduced pressure. (Note: this reaction should not be run more concentrated than specified – concentration has been optimized against eliminative biproducts) 43 3-(2-methoxyethoxy)prop-1-yne (9) 45% 1H NMR (500 MHz) (CDCl3) δ: 2.40 (t, 1H, CH2CCH, J = 2.4 Hz) 3.35 (s, 3H) 3.54 (m, 2H, CH2OCH3) 3.65 (m, 2H, CH2OCH2CC) 4.17 (d, 4.17, J = 2.4 Hz) 13C NMR (500Hz) (CDCl3) δ: 58.58, 59.20, 69.09, 71.83, 74.76, 79.70 3-(2-(2-methoxyethoxy)ethoxy)prop-1-yne (10) 71% 1H NMR (500 MHz) (CDCl3) δ: 2.39 (t, 1H, CH2CCH, J = 2.5 Hz) 3.33 (s, 3H, OCH3) 3.51 (m, 2H) 3.61 (m, 2H) 3.65 (m, 4H, OCH2CH2O) 4.16 (d, 2H, CH2CCH, J = 2.4 Hz) 13C NMR (500Hz) (CDCl3) δ: 58.55, 59.19, 69.25, 70.58, 70.70, 72.06, 74.67, 79.79 2,5,8,11-tetraoxatetradec-13-yne (11) 80% 1H NMR (500 MHz) (CDCl3) δ: 2.38 (t, 1H, CH2CCH, J = 2.4 Hz) 3.32 (s, 3H, OCH3) 3.49 (m, 2H, CH2OCH3) 3.61 (m, 10H, OCH2CH2O) 4.14 (d, 2H, CH2CCH, J = 2.5 Hz) 13C NMR (500Hz) (CDCl3) δ: 58.50, 59.14, 69.20, 70.52, 70.63, 70.71, 72.04, 74.64, 79.77 2.2.4.5 Synthesis of Model Compounds 12 – 15127 A magnetic stirrer, Azide (6 – 8) and chloroform (such that the concentration of alkyne+azide in chloroform = 0.6M) were added to a Schlenk flask followed by the alkyne (9 – 11, 2.1 equiv. for azide 8, 1.2 equiv. otherwise). IMPORTANT: this order must be used; under NO CIRCUMSTANCES should catalyst be added to neat precursor materials. Catalytic Tris(triphenylphosphine)copper(I)bromide was then added at a rate of 2% mol relative to the molar amount of the azide. Three freeze-pump-thaw cycles were carried out in order to de-gas the reaction (synthesis of Tris(triphenylphosphine)copper(I)bromide is described elsewhere). Following this the reaction was placed on an oil bath and heated to 60°C for 24h with stirring. Nitrogen was not reintroduced into the reaction after the last freeze-pump-thaw, so the atmosphere in the reaction should be mostly chloroform. Some refluxing off the side was 44 observed. Following the reaction, the chloroform was extracted with three washes of 0.1 disodium EDTA pH 8. In all cases the final EDTA wash was colorless. Aqueous layer was back extracted once with CH2Cl2; the combined organic layer was then dried over sodium sulfate and concentrated using a rotovap. Material was purified using silica gel chromatography with CH2Cl2 eluent containing 8 – 10% methanol v/v%. Materials were pale yellow to colorless oils. 6EO2T was observed to crystalize spontaneously below room temperature. 12 6EO1T 3.9g, 70% HR-ESI-MS Calculated C15H30N3O6 (M+H)+: 348.2135, Observed: 348.2138 1H NMR (500MHz) (CDCl3) δ: 3.32 (s, 6H, OCH3) 3.50 (m, 4H, CH2OCH3) 3.57 (m, 12H, OCH2) 3.81 (t, 2H, N-CH2CH2O, J = ) 4.48 (t, 2H, N-CH2CH2-O, J=) 4.63 (s, 2H, OCH2-triazole) 7.70 (s, 1H, triazole H) 13 C NMR (500 MHz) (CDCl3) δ: 50.33, 59.15, 64.73, 69.59, 69.74, 70.61, 70.64, 70.66, 72.03, 123.93, 145.06 IR (neat): 3569 (water), 3136, 2873, 1956, 1641, 1547, 1460, 1353, 1247, 1199, 1102, 932, 850, 776 13 8EO1T 74% HR-ESI-MS Calculated C19H38N3O8 (M+H)+: 436.2659, Observed: 436.2670 1H NMR (500MHz) (CDCl3) δ: 3.32 (s, 6H, OCH3) 3.50 (m, 4H, CH2OCH3) 3.59 (m, 20H, OCH2) 3.82 (t, 2H, N-CH2CH2O, J = 5 Hz) 4.48 (t, 2H, N-CH2CH2-O, J = 5Hz ) 4.63 (s, 2H, OCH2-triazole) 7.69 (s, 1H, triazole H) 13C NMR (500 MHz) (CDCl3) δ: 50.35, 59.15, 64.74, 69.61, 69.76, 70.62, 70.65, 70.70, 70.73, 72.06, 123.92, 145.07 IR(neat): 3566 (water), 3137, 2873, 1957, 1645, 1545, 1457, 1351, 1297, 1247, 1199, 1105, 1048, 984, 850, 776 45 14 6EO2T 71% HR-ESI-MS Calculated C18H33N6O6 (M+H)+: 429.2462, Observed: 429.2457 1H NMR (500 MHz) (CDCl3) δ = 3.31 (s, 6H, OCH3) 3.51 (m, 8H, OCH2) 3.64 (m, 4H, OCH2CH2OCH2triazole) 3.78 (t, 4H, N-CH2CH2O, J = 5Hz ) 4.47 (t, 4H, N-CH2CH2-O J= 5 Hz) 4.64 (s, 4H, OCH2-triazole) 7.66 (s, 2H, triazole H) 13C NMR (500 MHz) (CDCl3) δ = 50.33, 59.13, 64.86, 69.60, 69.79, 70.56, 71.97, 76.97, 77.23, 77.48, 123.83, 145.12 IR(neat): 3537 (water), 3137, 2875, 1944, 1652, 1549, 1459, 1361, 1292, 1223, 1198, 1094, 1049, 982, 924, 892, 848, 776 15 8EO2T 77% HR-ESI-MS Calculated C22H41N6O8 (M+H)+: 517.2986, Observed: 517.2992 1H NMR (500 MHz) (CDCl3) δ: 3.33 (s, 6H, OCH3) 3.51 (m, 8H, OCH2) 3.59 (m, 4H) 3.62 (m, 4H) 3.79 (t, 4H, N-CH2CH2O, J=5 Hz) 4.47 (t, 4H, N-CH2CH2-O, J=5 Hz ) 4.64 (s, 4H, OCH2-triazole) 7.67 (s, 2H, triazole H) 13C NMR (600 MHz) (CDCl3) δ = 50.30, 59.10, 64.77, 69.56, 69.85, 70.52, 70.58, 70.62, 72.01, 123.86, 145.07 IR (neat): 3557 (water), 3137, 2892, 1955, 1646, 1549, 1459, 1354, 1294, 1245, 1223, 1199, 1100, 982, 928, 892, 848 46 2.3 Results and Discussion 2.3.1 Ab Initio Calculations Lithium ion affinities with various nitrogen heterocycles are calculated using the MP2(full)/Aug-cc-pVTZ(Li-C)//MP2(full)/cc-pVDZ(Li-C) calculation recommended for this kind of estimate by Rodgers et al. which we show to be in good agreement with the G3 and G3(MP2) calculations of Pople and co-workers. G3(MP2) was found to be the most amenable to larger species, so we use this level of theory to model a hypothetical solvation shell for the lithium ion with and without triazole participation. The absolute ligand – lithium association energies of heterocyclic and other ligands have been extensively studied by Rodgers and co-workers, but computational estimates accompanying the measurements have been carried out using calculations with varying levels of sophistication.52-54 Additionally, Rodgers et al. have benchmarked the MP2(full)/Aug-ccpVTZ//MP2(full)/cc-pVDZ calculation against a test set which included few nitrogen heterocycles.51 In order to test the applicability of this calculation to nitrogen heterocycles we have extended these calculations to azines and azoles, and found similar agreement to experiment as the initial test set (fig. 14). Additionally we have two bidentate lithium complexes at this level of theory on models designed to resemble complexation geometries expected in the model compounds. As the number of dative bonds between lithium and its coordination sphere increases, the strength of each additional dative bond has been seen to decrease in previous studies.43 It is notable however that while 1-H-1,2,3-triazole shows an association energy 51.5 kJ/mol greater than dimethyl ether, the difference between the binding energy of stronger of the two bidentate complexes and glyme is only 15.1 kJ/mol. This result is attributable to the geometries of the two complexes; the 1-H-1,2,3-triazole minimum is a scalene triangular 47 complex, which features bonds from the two adjacent aprotic nitrogen atoms to the lithium ion, whereas the minimum observed in the 4-methoxymethyl-1H-1,2,3-triazole (4MeOMeT) complex features only one lithium nitrogen bond. Attempts to calculate the energies of larger complexes became impractical due to the prohibitive expense of the MP2(full)/Aug-cc-pVTZ(Li-C) single point calculation on complexes featuring coordination numbers of three and four. A small comparison of G3 and G3(MP2) energies to experiment and theory for only the most relevant glyme and triazole species was conducted to evaluate the appropriateness of these methods (fig. 14). The agreement of G3 theory with mass spectrometry experiments was tested for lithium association calculations, and found to have a mean average deviation of 8.6 kJ/mol compared to 8.1 kJ/mol for MP2(full)/Aug-cc-pVTZ(Li-C)//MP2(full)/cc-pVDZ(Li-C) in the test set of Rodgers et al.51 Additionally both G3 and G3(MP2) are extensively benchmarked for general thermochemical accuracy in a variety of applications.56,57 Larger coordination spheres were modeled using two distinct “chains” up to a coordination sphere of four. Justification for this treatment can be found in molecular dynamics simulations which show that lithium cations complexed between two chains are the most important for lithium ion transport, and that the average occupancy of the first coordination shell around lithium contains four.19 oxygens, meaning that four and five coordinate complexes should be most important in transport behavior, with lithium rarely containing less than four ligands.19 48 G3(MP2) Energies of Reconstructed Solvent Shells for Li+ Using Glyme Based Ligands Glyme solvent shells without triazoles Glyme solvent shells with 1 triazole 430 380 kJ/mol 330 280 230 0 1 2 3 4 5 Coordination number Figure 13 – As more solvent moieties are added to the lithium coordination sphere the average bond strength decreases, effecting both triazole and ether ligands. Triazoles can interact with the 2p orbitals of the lithium ion leading to net stabilization in the two and three coordinate complexes which are planar. Lithium becomes sp3 hybridized in the tetracoordinate complex, and this effect is seen to diminish. Simulations and experimental data have shown four and five membered complexes to be most common in polyether ion conductors.19 49 a) Lithium Association Energies in Theory and Experiment Present work Experiment Rodgers et al. 300 250 Lithium 200 Association Energy 150 (kJ/mol) 100 50 Figure 14 – Gas phase lithium ion to ligand affinities in experiment and theory. Typical agreement between the experiments of Rodgers et al.51-54 and the MP2(full)/Aug-cc-pVTZ(LiC)//MP2(full)/cc-pVDZ(Li-C) calculations recommended by the same group for quantitatively accurate lithium ion affinities are shown in (a) .51 Calculations typically over estimate affinities relative to experiment but are usually within 10 kJ/mol, which is comparable to the uncertainty of the experiment. In (b) G3 methods were compared to the methods of Rodgers et al. due to unfavorable scaling of the latter to larger ligand systems.51 The computational expense of G3 is similar to that of the Rodgers method, with G3(MP2) being somewhat cheaper. G3(MP2) was found to be in better agreement with experiment due to being consistently lower in its energy estimates. 50 Figure 14 (cont’d) b) Calculated and Measured Li+ Energies with G3 Methods MP2(full) composite) G3 G3(MP2) Experiments 280 260 240 220 kJ/mol 200 180 160 140 120 100 1H-1,2,3-triazole glyme 2H-1,2,3-triazole 4-MEOMET c) The behavior seen in our three and four coordinate complexes (fig. 13) shows that as the coordination number increases, the lithium triazole bond becomes roughly indistinguishable from a lithium ether bond on the basis of energy. The difference in energies between the four coordinate complex with and without a triazole is approximately 3 kJ/mol. 51 2.3.2 Experimental Measurement of Conductivity and Thermal Behavior Model compounds 8EO1T, 6EO1T, 8EO2T, and 6EO2T were first synthesized using the methodologies described by scheme 2. Model compounds were designed such that their molecular weights cluster around 500 g/mol so that they can be fairly compared to poly (ethylene glycol) dimethyl ether Mn=500 ( henceforth PEGDME 500), and such that each model gives a whole number ratio of ether oxygen atoms and triazole rings; 8:1, 6:1, 4:1, and 3:1 respectively. The model compound 6EO2T was also devised intentionally to make five and six coordinate complexes containing only ether oxygens uncommon, so that triazole containing complexes resembling the one shown in fig. 13 would be relevant to the transport behavior. Synthesized materials were purified and dried as described in the experimental section. Dry materials were then analyzed by differential scanning calorimetry without additives, and by AC impedance spectroscopy as neat materials with dissolved LiTFSI. The thermal behavior of PEGDME500 was not characterized, because our equipment cannot access temperatures less than -80°C. 6EO1T was found to lack thermal behavior in the available temperature window, and was therefore not used in conductivity measurements; the observed lack of thermal behavior was probably due to the fact that 6EO1T has the lowest molecular weight of the model compounds. 52 Table 1 – Physical Data Pertaining to Thermal and Conductive Properties of Materials Compound Melting Glass Temperature, Transition Tm (°C) Temperature, Tg (°C) Activation Energy, Ea (kJ/mol) Pre-exponential factor, σ0 (S/cm) Arrhenius fit R2 8EO1T, 13 - -74.9 29.7 1.19∙103 0.9707 6EO1T, 12 - - n/a n/a n/a 8EO2T, 15 - -59.6 40.4 3.13∙105 0.9872 6EO2T, 14 22.6 -59.1 41.8 5.21∙105 0.9807 PEG 500 DME - - 17.5 17.8 0.9583 It was found that the model compounds 6EO2T, 8EO2T, and 8EO1T all had measurable glass transition temperatures (Tg) and that the measured glass transition was weakly dependent on the ether oxygen to triazole ratio, and more strongly dependent on the number of ether oxygens in the chain (Table 1.). 6EO2T and 8EO2T had Tg that were almost identical, and 8EO1T had a Tg roughly 6 degrees lower. 6EO2T was shown to have a melting temperature near room temperature. Crystallization behavior was noticeable in 6EO2T at reduced temperatures (including low temperature storage), however room temperature crystallization of samples was only observed in one occasion, whereas the material usually maintained fluidity at room temperature. Because of this and the fact that the lowest conductivity measurements taken occurred at 30°C, crystallization behavior was not observed to affect the conductivity of the material directly. 53 a) Conductivtity of Oligomer Complexes 1.00E+00 Conductivity S/cm 2.7 2.9 3.1 3.3 PEG500 1:128 PEG 500 1:64 1.00E-01 PEG500 1:32 8EO2T 1:64 LiTFSI 1.00E-02 PEG 500 1:64 LiTFSI 6EO2T 1:64 LiTFSI 8EO1T 1:64 LiTFSI 1.00E-03 1000/K b) Conductivity of Oligomer Complexes 1:64 LiTFSI Conductivity (S/cm) 1.00E+00 2.7 2.8 2.9 3 3.1 1.00E-01 3.2 3.3 3.4 PEG 500 8EO2T 6EO2T 1.00E-02 8EO1T 1.00E-03 1000/K Figure 15 – Conductivity of oligomer salt complexes. In (a) model oligomer salt complexes were run at a concentration of 1 Li : 64 ligand atoms, where two of the triazole nitrogens were considered ligands (but not the pyrrole-like nitrogen) run with PEG 500 dimethyl ether controls. Model oligomers and the PEG control were run with LiTFSI, while a variable concentration standards curve was run with LiClO4. In (b) the same data shown without standards. 54 a) 303K conductivity vs GlassTransition Temperature y = -0.0004x + 0.087 R² = 0.9999 0.01 0.009 0.008 0.007 0.006 σ (S/cm) 0.005 0.004 0.003 0.002 0.001 0 195.0 200.0 205.0 210.0 215.0 220.0 T (K) b) Entropy - Enthalpy Compensation Behavior in Model In PEG Based Materials with Increasing In-Chain Triazole Content 14 y = 41.646x - 5.0191 12 R² = 0.9901 10 ln(σ0) 8 6 4 2 0 0.100 0.200 0.300 0.400 0.500 Ea (eV) Figure 16 – Descriptions of trends in the conductivity of oligomer salt complexes. In part (a) a strong correlation between conductivity at 30°C and the glass transition temperature is found within the model series. In part (b) a linear relation is shown between the pre-exponential factor and activation derived from Arrhenius plotting in PEG and the triazole containing model compounds. 55 A crystal of 6EO2T was obtained for single crystal X-ray diffraction analysis by slow evaporation of a toluene solution in a -20°C freezer. While cases of triazole C-H to heteroatom hydrogen bonding have been reported in the literature,46 hydrogen bonding was not present in the crystal structure as the closest intermolecular N-H distance was 2.75Å and the shortest O-H distance was 2.79Å. Triazoles were not observed to pi stack in the crystal. While compound was observed to crystalize in layers (fig 17b) the faces of the triazole rings seem to avoid one another (fig 17c). The triazole ring does carry a dipole along which the rings in the model compound seem to align (fig 17d). We conclude that the most important factors that lead to ordering and crystallization in the most triazole rich model are loss of conformational freedom and dipole dipole interactions. The 30°C conductivity of 6EO2T and 8EO2T salt composites was nearly identical, with 8EO1T being half an order of magnitude and PEGDME 500 being a full order of magnitude higher (Fig 1.). Room temperature conductivity was shown to correlate nearly perfectly with the Tg of the material. It was observed that as the temperature was increased, the conductivity of the materials approached convergence at a single value. This behavior is known as compensation law, or Meyer-Neldel behavior (Fig 2.).66-68 Meyer-Neldel or entropy-enthaply compensation behavior is a behavior of a set of processes or reactions that occur in families of materials with similar compositions which are well described by the Arrhenius equation −Ea σ(T) = σ0 e RT (eq. 10) where σ(T) is temperature dependent conductivity, Ea is the activation energy of the process, σ0 is an empirical exponential prefactor, and R is the gas constant.66-68 56 a) b) Figure 17 – Single crystal X-ray diffraction of 6EO2T. In part (a) the Single Crystal XRD structure of 6EO2T is shown with thermal elipsoids set at 50% probability. Packing as viewed from the b axis of the 6EO2T crystal is shown in (b) and the c axis in (c). While a layered structure is evident in the crystal, pi-pi stacking interactions and hydrogen bonding appear to be absent. The angle shown in (c) reveals that triazole moieties align roughly along the dipole of the ring within the layers. 57 Figure 17 (cont’d) c) d) 58 Table 2 – Crystal Data and Structure Refinement for 6EO2T Identification code 6EO2T Empirical formula C9H16N3O3 Formula weight 214.25 Temperature/K 173.01 Crystal system monoclinic Space group C2/c a/Å 47.5520(19) b/Å 5.5312(2) c/Å 8.1912(3) α/° 90.00 β/° 97.576(3) γ/° 90.00 3 Volume/Å 2135.64(14) Z 8 3 ρcalcmg/mm 1.333 -1 m/mm 0.843 F(000) 920.0 3 Crystal size/mm 0.189 × 0.066 × 0.059 2Θ range for data collection 3.74 to 140.76° Index ranges -57 ≤ h ≤ 57, -6 ≤ k ≤ 6, -9 ≤ l ≤ 9 Reflections collected 14377 exptl absorpt T max, min 0.7533, 0.6448 Independent reflections 1987[R(int) = 0.2141] Data/restraints/parameters 1987/0/138 2Θ 70.38 fraction collected 0.979 Goodness-of-fit on F2 1.007 Final R indexes [I>=2σ (I)] R1 = 0.0620, wR2 = 0.1222 Final R indexes [all data] R1 = 0.1497, wR2 = 0.1585 -3 Largest diff. peak/hole / e Å 0.28/-0.26 Compensation behavior is an apparently exponential dependence observed between the pre-exponential term and the activation energy appear exponential related such that Ea = α + β ln(σ0 ) (Eq. 11) 59 where α and β are arbitrary constants, σ0 is the pre-exponential term, and Ea is the activation energy.67,68 Controversy exists over what gives rise to this sort of behavior and what (if anything) it signifies.68 This behavior is rarely discussed in the context of polymer electrolytes, however one example of compensation behavior was identified by Wieczorek in an investigation of a series of polymer composite materials.67 These materials included various polyethylene glycols (PEG) and blends of PEG with poly methylmethacrylate (PMMA), which were paired with NaI or LiClO4 carriers and a variety of inorganic nanoparticle fillers.67 Wieczorek cited earlier work from studies of diffusion in metals in which activation energy was related to the entropy of migration (ΔSm) by a characteristic temperature (TD or disordering temperature) such that Ea/TD = ΔSm .66,67 In earlier study TD was considered to be the melting point of the class of alloys showing compensation behavior.66,67 Wieczorek calculated TD for his materials (1 distinct TD for each set of materials showing compensation behavior) and found that it was close to the Tm of the crystalline PEG domains in his materials.67 Reference to the effects of inorganic fillers was used to explain the discrepancy.67 While the work of Wieczorek is an interesting precedent, it does not provide an explanation for why the compensation behavior is present in these materials. Furthermore, references to a TD in our materials could not be related to melting, as only one of our materials shows a Tm. In order to explain and interpret our results we will look to physical theories of polymer dynamics, as well as Arrhenius based models. 2.3.3 The Explanation for and Significance of Compensation Behavior It is generally understood that segmental dynamics of polymer electrolytes are dependent on the mobility of the individual segments of the polymer chain.5,9,14,15 The connection is 60 conveniently rationalized using the dynamic bond percolation theory (DBP) of Ratner and coworkers.11-15 A bond in the sense of DBP, is a pathway between a void in the polymer host occupied by an ion, and an unoccupied void. When one bond has opened and closed for each ionic species in the system it can be said that one renewal time has occurred. Diffusion of an ionic species can then be written as14 D= 〈r2 〉 (eq. 12) 2d𝜏R Where τR is the renewal time 〈r2〉 is the mean square displacement of a randomly diffusing ion in the system, and d is the spatial dimensionality of the system.11 The connection between the Tg and τR is somewhat foggy. A general definition of the glass transition temperature can be found in Anslyn and Doughrty’s Modern Physical Organic Chemistry; “[a] transit from an essentially rigid glass to a more flexible rubbery material”.131 Based on this definition it would be intuitive to assume that renewal time becomes essentially infinite at the glass transition temperature, and would therefore be inversely proportional to T-Tg as the temperature of a material rises above its Tg. This logic also underlies the VTF equation (eq. 3) which makes temperature dependent conductivity σ(T) inversely proportional to T-T0, where T0 is a fitting parameter related to Tg by a constant (usually less than 45°C).15 However as the replacement of Tg with T0 suggests there is some amount of ambiguity in this idea.15 The ambiguity is generally related to the fact that Tg is an empirical kinetic quantity related to molecular motion in a bulk system, and that different types of motion are exhibited by polymers.15 Thus different experimental techniques may find different values of Tg.15 Further complexity is introduced by the fact that the addition of a salt to a polymer system increases it’s 61 Tg by introducing dative bonds between and within chains.15 These problems mean that a formal functional relationship between τR and Tg has not been established. This complexity makes interpreting the correlation we found between room temperature conductivity and Tg somewhat difficult. While we cannot use DBP quantitatively to explain this result, the conceptual connection between Tg and molecular motion is still the best way to understand it. Materials with a higher Tg are behaving as though they are at a lower temperature than those with a low Tg because molecular motion (and hence renewal behavior) doesn’t vary strongly with temperature below the Tg (and in fact stops for all intents and purposes). A physical theory of cation transport based on the Rouse model was derived by Maitra et al.23 This model breaks transport down into a component mediated by diffusion of the ion with a chain (Dc.m.) and three types of independent diffusion (DM) with three independent time scales (τ1, τ2, τ3).23 These consist of diffusion along a chain (τ1) relaxation mediated diffusion (τ2) and interchain hopping (τ3) which can be considered analogous to the τR of Ratner et al.23 It was shown that for short chains such as those in our study that an approximate functional form can be written for DM(τ1, τ2, τ3) such that DM = 𝑹2𝑒 (eq. 13) 18𝜏3 Where Re is the equilibrium end to end distance of the polymer.23 Because parameters of chain flexibility mostly effect τ2, we can reason that the stiffening effect of introducing triazoles into a chain are only going to be felt if they effect the diffusion behavior of the polymer for some reason, or the diffusion of lithium ions between chains. 62 Additionally we considered possible effects of the differing number of Rouse segments (NR) which would affect the available Rouse modes; a set of modes that describe polymer motion. We might expect that decreasing NR would lead to less thermal energy being lost to coiling movements which might lead to an increase in Dc.m.. This trend is in fact shown by Maitra et al for polymers ranging from NR= 1 to ~400 where Dc.m. goes to zero.23 The authors used PEG models and defined a rouse segment to be one monomer. We estimated NR in our models by using the number of EO monomers and considering a triazole and the ether oxygen after it to be one segment. Using this system we found NR=11 for PEGDME 500, 8 for 8EO2T and 8EO1T, and 6 for 6EO2T. Based on the relatively small differences, and the fact that NR doesn’t appear to track with differences in the conductivity, we are disinclined to pursue this line of reasoning further. The differences in exponential prefactor observed in the model compounds is difficult to explain, however recent work by Frech et al has focused on understanding the origins of the exponential prefactor in the conductivity of organic liquids, and using this insight to improve the Arrhenius formalism.69-72 Citing deficiencies in both phenomenological approaches (such as Arrhenius, and Vogel Tamman Fulcher or VTF) which tend to yield little physical insight into a system, but fit data well, and hydrodynamic theory (Nernst-Einstein, DBP) which are theoretically rigorous, but often fail to adequately describe experimental results, Frech et al. have developed the compensated Arrhenius formalism (CAF).69-72 The compensated Arrhenius Formalism starts with the insight that the exponential prefactor in the Arrhenius equation is actually a function of the static dielectric constant of the material, which is itself a temperature dependent quantity. The Arrhenius equation that results from this insight can be written −Ea σ(𝜀𝑠 , T) = σ0 (𝜀𝑠 (𝑇))e RT (eq. 14) 63 where εs is the static dielectric constant of the material. The authors then devised a fitting method whereby the pre-exponential factor could be cancelled, and calculated separately from the activation energy.69-72 They accomplished by normalizing to a conductivity measurement at a reference temperature (Tr) and fitting the data using the compensated Arrhenius equation, which they give as. 𝜎(𝑇,𝜀𝑠 ) 𝑙𝑛 (𝜎 𝐸 𝐸 ) = − 𝑅𝑇𝑎 + 𝑅𝑇𝑎 𝑟 (𝑇𝑟 ,𝜀𝑠 ) (eq. 15) 𝑟 The activation energy (Ea) can then be obtained as a slope or intercept of the fit.69 The preexponential factor is calculated separately, and must be obtained from a set of related materials that vary regularly by dielectric constant.69 The pre-exponential factor is given by transforming the conductivity data so that 𝜎0 = 𝜎 (eq. 16) ̅𝑎 −𝐸 𝑒 𝑅𝑇 Where 𝐸̅𝑎 is the average activation energy for the entire set of materials analyzed. While this procedure would be impractical for our own data, due to the need for the materials analyzed to be sets that vary by a single parameter (e.g. primary alcohols of varying chain length from ethanol to octanol) the insights gained from the development of this formalism are quite useful.69-72 When this method was used to analyze the ionic conductivity of various ions in families of polar organic liquids conductivity of each liquid in a class (i.e. 1-alcohols or methyl ketones of varying chain length) varied roughly linearly by temperature dependent dielectric constant ε(T) and gave rise to separate curves when plotted. On the other hand, the pre-exponential factors of each class of liquids overlapped in a single curve when plotted against 64 ε(T). This is a good indication that their assumptions about the dependence of pre-exponential factor on dielectric constant are likely justified. Dielectric constant isn’t a useful metric for thinking about molecular details, and structure activity relationships, as it is a macroscopic property of a system.71 In order to make their model more useful the authors used Onsager’s model to relate dielectric constant to permanent dipole, and dipole density of sets of thiols, methyl ketones, nitriles and acetates of various chain lengths.71 They used a version of the CAF adapted to diffusion, and showed that the pre-exponential factor D0 varied by Nd/T (where Nd is the dipole density of the material) and that it varied by solvent class.71 The dipole density used in this study was a number density, which was easily obtained because the authors used liquids with only one polar functional group per molecule.71 Thus the were able to calculate the quantity from the molar volume.71 This was true because very strong correlations were present between ε(T) and Nd(T).71 Finally, it was shown that alcohols had higher activation energies than the polar aprotic liquids studied.69,70 This was attributed to the hydrogen bonding capabilities of alcohols, which required additional energy to dissociate relative to polar aprotics.72 The molecules used in the present study are more complicated than those examined by Frech et al. in that they are large and contain many polar groups per molecule. One comparison that is easy to make however is the strength of the permanent dipole moment in a 1,2,3- triazole ring, relative to that of dimethyl ether, the basic dipole creating moiety in a chain of polyethylene glycol. The dipole moment of dimethyl ether has been experimentally measured to be 1.310 D, additionally, ethyl methyl ether has a dipole moment of 1.174 D.73 The dipole for 1,3-dimethyl1,2,3-Triazole has not been measured experimentally, however we have calculated the dipole at the MP2(full)/6-31G(d) level of theory and found a value of 1.4 D for dimethyl ether, and a 65 value of 4.7 D for the triazole. Additionally and in contrast to standard PEG chains, the triazole is known to be a hydrogen bond donor with roughly the same affinity for an acceptor as pyrrole.44 Based on the factors considered up to this point an explanation for the observed compensation behavior can be proposed. It seems likely that the introduction of the triazole moiety into the PEG chain provides a ligand for the lithium ion similar to that of an ether oxygen. However the triazole differs significantly in the magnitude of its dipole which produces effects that both enhance and impede conductivity. Triazoles stiffen the chains and (probably more importantly) enhance chain to chain dipole-dipole interactions, which lead to an increase in Tg and lead to crystallization in the extreme case of 6EO2T. The greater attraction between chains leads to a higher activation energy for transport as triazoles become a greater fraction of the ligands in the material. However, conductivity can also be enhanced by the presence of triazoles. This occurs because the greater polarity of the triazole moiety enhances the Arrhenius pre-exponential factor which enhances the global conductivity of the material at all temperatures. A mechanism proposed by Frech et al. for the enhancement of the pre-exponential factor cites transition state theory of transport processes and ties the polarity of the environment to the ΔG‡ of a moving particle.72 This proposal was favored in part because the authors have observed similar dependencies on the pre-exponential for self-diffusion of polar liquids.70,72 A similar effect on self-diffusion of our systems would be unexpected based on the observed thermal behavior, however the polarity likely is affecting the environments of the mobile ions. We propose that the presence of strong dipoles is stabilizing to individual ions in the system, and helps them overcome coulombic correlation to their counter ion. This leads to a higher effective concentration of ions mediating transport. 66 2.4 Conclusions As a potential architectural feature of lithium ion elecrolytes, triazoles have some degree of potential. Triazoles do have a negative effect on conductivity of polymer salt composites, but it is relatively modest, and the concentrations of triazoles studied were quite high; exceeding most plausible concentrations of the moieties one would expect to find in functional materials. Triazoles seem to exert most of their effects on conductivity through their dipole moment which is significantly stronger than that of dimethyl ether or polyethylene glycol. This has the effect of attracting the chains together, inducing crystallization and increasing the glass transition of the material. The stiffness of the triazole may also contribute to these effects. The deleterious effects of the triazole moiety on conductivity manifest themselves in the increase in activation energy observed for conductivity seen in the Arrhenius model of the process. However increases in dipole density have also been shown to enhance the preexponential factor of these processes, which leads to compensation behavior. Frech et al. who first observed effects of this kind proposed that increasing the dipole density of conductive materials might be a novel way to increase conductivity in polymer electrolytes. While it has been shown in this work that triazoles have undesirable effects that counter the pre-exponential boost in the particular systems studied, it is possible to envision strategic uses of such moieties in electrolyte design, such as placing strong dipoles (triazoles or otherwise) near stationary anions found in single ion conductors in order to activate charge separation. Strategies such as this warrant future study and may be the subject of future work. 67 3 3.1 Chapter 3: Nucleofugality in Nitrogen and Oxygen derived leaving groups* Introduction Nucleofugality, or leaving group ability, is a fundamental concept of organic chemistry, and plays a key role in a broad array of chemical reactions. Despite its centrality to reactions such as E1, E2, SN1 and SN2, that feature a leaving group (nucleofuge) departure in the rate limiting step, nucleofugality was sparsely studied until fairly recently.80 The last decade, however, has seen several attempts to develop an absolute scale of nucleofugality.81-84 These began with the work of Ayers et al. who attempted to use a truncated Taylor series to model the electronic energy of a leaving group as a function of increasing charge. In that expression the first order term is μ, the electronic chemical potential (which can be expressed as -[I+A]/2) and the second order term is η, or chemical hardness (expressed as [I-A]).81 Using this construction they argued that electrophilicity ω, could be defined as μ2 (𝐼+𝐴)2 ω = 2η = 8(𝐼−𝐴) (eq. 17) Where I is the ionization potential and A is electron affinity; thus this formulation approximates continuous derivatives of energy with respect to charge based on quantities that represent a change in energy with the gain or loss of a full electron.82 Electrophilicity in this sense is described as “the energy [of] stabilization resulting from the presence of a perfect electron donor”.81 In an attempt to correct for partial charge already present in a leaving group prior to leaving, they derived a related quantity ΔEnucleofuge which is defined such that * This chapter is an adapted republication of Spahlinger, G.; Jackson J. E. Phys. Chem. Chem. Phys. 2014, 16, 24559 – 24569. It has been republished with permission from the PCCP Owner Societies. The original article may be found online at the following link: http://pubs.rsc.org/en/content/articlelanding/2014/cp/c4cp03741c#!divAbstract 68 ∆𝐸nucleofuge = (μ+η)2 2η = (𝐼−3𝐴)2 (eq. 18) 8(𝐼−𝐴) Because ΔEnucleofuge is derived solely from the ionization potential and electron affinity, this quantity is relatively easy to calculate, and several groups have followed up by conducting DFT studies wherein attempts were made to apply or refine this scale.82,83 Most notably, Geerlings et al. modified the theory to include solvent effects, and applied the resulting formalism to an extended set of leaving groups.82 Mayr et al., have taken a different approach, utilizing an empirical scale parameterized with rate constants for the solvolysis of benzhydryl derivatives.84 The benzhydryl group has the advantage of being tunable via addition of electron donating and withdrawing groups on the aryl rings, such that leaving groups whose solvolysis rate constant is too fast or slow for study on one scaffold can be measured on another.84 The group focused on sulfonate, carboxylate and halide leaving groups in this analysis, and claims to have found a scale that is useful for rates spanning 12 orders of magnitude.84 A noticeable omission from the recent literature on nucleofugality is the amine-derived anionic leaving group.81-84 While sulfonates and carboxylic acid esters are relatively common, amides, sulfonamides, imides and sulfonimides have to the best of our knowledge been absent from any study of nucleofugality to date. Attempts to activate amines for substitution and elimination do exist in the literature however, and date back to the 1960s. Based on its low pKa of 1.6,85 initial work explored derivatives of saccharine.86 Unfortunately these were found to undergo preferential attack at the carbonyl carbon; however, the authors discovered that bis(sulfonyl)imides (e.g. ditosylamines) could undergo substitution and elimination.86 The most common activation in this vein appears 69 to be through the addition of dual triflyl groups to form bis(trifluoromethanesulfonyl)imide derivatives.87-89 This strategy for activation is becoming more common in part because the bis(trifluoromethanesulfonyl)imide (TFSI) anion is an attractive component in certain types of ionic liquids.90 Metal salts and ionic liquids derived from TFSI have attracted a great deal of attention from scientists researching transport materials for lithium ion batteries. TFSI is generally considered to be a poorly associating ion; it is also thought to plasticize polymeric lithium ion conductors, leading to a lower glass transition temperature in the polymer, and hence better conductivity than other anions of similar lithium ion affinities.90,91 Despite this trend, the activation of nitrogen as a nucleofuge remains a rare strategy. While various researchers have pointed out the viability of alkyl TFSI derivatives for the synthesis of ionic liquids,88,89 TFSI containing liquids are more commonly accessed by the general synthetic method used for ionic liquids:92 an onium halide salt is first formed by reaction of an alkyl halide with an amine; it is then subjected to ion exchange metathesis by treatment with silver TFSI.92 We elected to study the nucleofugality of polyatomic anionic oxygen and nitrogen derived leaving groups by modeling the Menshukin reaction, in which ammonia displaces a leaving group by an SN2 mechanism. The SN2 reaction is itself much better studied than nucleofugality as a general concept; theoretical studies exist for both ionic and Menshutkin-type SN2 reactions, including solvent effects,93,94 SN2 reactions at neutral nitrogen,95,96 comparisons of front side vs. back side SN2,97,98 studies employing valence bond methods,99 analyses of SN2 based on Marcus theory,100 and analyses of the influences of periodicity on the anionic SN2 reaction.118,119 Additionally, the formation of quaternary amine mesylates via the Menshutkin reaction has been modeled using DFT methods.101 Although we are unaware of any recent 70 reviews of theoretical work on the SN2 reaction, a contribution from Laerdahl and Uggerud provides a good perspective on the state of the field as of twelve years ago, including discussion on experimental mechanistic work, and reaction dynamics.102 Surprisingly there seem to be no studies that systematically analyze and compare the reactivities of nitrogen and oxygen derived polyatomic anionic leaving groups as a class. Reservations have previously been expressed about using SN2 reactions as a probe of nucleofugality.80 In particular Stirling argues in his 1978 account that SN2 and E2 reactions are tainted by the involvement of a nucleophile or base in the rate limiting step of the reaction.80 While it is true that the nucleophile is an integral part of an SN2 reaction, the present work controls for this issue by using the same nucleophile throughout the study. Moreover, studies of bimolecular reactions are necessary to understand the role of nucleofugality in mechanisms that feature electronic reorganization concurrent with leaving group departure. 3.2 Computational Methods All calculations were performed using GAMESS versions 12 R3 (2009) and 1 R1 (2012).55 Calculations were run on a personal laptop, the MSU chemistry department hydra cluster, or the MSU High Performance Computing Cluster (HPCC) depending on the demands of the job. Activation energies were calculated by finding minima for Van der Waals complexes of ammonia and each respective alkylating agent shown in scheme 1, then by locating transition states for the SN2 reaction. ΔEǂ was considered to be the difference in these two energies. ΔEcomplex is the difference in energy between the Van der Waals complex and the sum of ammonia and the alkylating agent being studied. Van der Waals complexes and transition state 71 structures were first located at the HF/3-21G level of theory, and in cases where the conformational space allowed multiple minima or transition state structures, the lowest energy of these were selected. Additional geometric optimizations were run at HF/6-31G(d), and MP2(full)/6-31G(d). In all cases vibrational analyses were run at HF/6-31G(d) on the HF/631G(d) geometries in order to confirm that minima and transition states had zero and one imaginary vibrations respectively. All calculations were initially run with C1 symmetry. After optimization, structures were found which converged to C1, Cs, C2, C2v and C3v symmetries. Structures which appeared to converge out of C1 symmetry were rerun at MP2(full)/6-31G(d) using the new point group. Coordinates for stationary points and their corresponding Abelian point groups are listed for all structures in the supporting information. In order to get relatively accurate energies economically, we have chosen to simplify the G3(MP2) method of Pople et al.57 The G3(MP2, CCSD(T)), or G3(MP2, CCSD) as it is also known, is the variant of G3(MP2) implemented in GAMESS.103 The difference between the two is that QCISD(T) calculations are not available in GAMESS, and therefore have been replaced by CCSD(T) calculations as shown in equation 3. E0[G3(MP2, CCSD(T))] = E[CCSD(T)/6-31G(d)//MP2(full)/6-31G(d)] + E[MP2(FC)/G3large//MP2(full)/6-31G(d)] – E[MP2(FC)/6-31G(d)//MP2(full)/6-31G(d)] + ZPE + HLC (eq. 19) Where HLC is a higher level correction and ZPE is the zero point energy at the HF/6-31G(d) level of theory scaled by an empirical factor of 0.8929.57 ,103 We have modified this method by omitting the CCSD(T)/6-31G(d) calculation and the higher level correction. For brevity we will refer to this as an “MP2/G3large” calculation, however it is defined below in equation 4. 72 E0[MP2/G3large] = E[MP2(FC)/G3large//MP2(full)/6-31G(d)] + ZPE (eq. 20) The quantities described as “ΔE” in this paper are ΔE0[MP2/G3large] energies unless otherwise indicated. ΔHǂ was also calculated for all activation energies by applying thermal corrections from the HF/6-31G(d) vibrational analyses which were calculated at 298K. MP2/G3large calculations of activation showed good agreement with the G3(MP2, CCSD(T)) in sulfonates (Supporting information). A second set of calculations at the CCSD(T)/6-31+G(2d,p)//MP2(full)/6-31G(d) level suggested that MP2/G3large might systematically overestimate barriers, however this level of theory not a feasible basis for the study at large. MP2/G3large calculations had mean average deviations (MAD) from experimental methyl cation affinity data similar to G3 and W1 calculations performed by Zipse et al. (Table 2).104 It is often considered important to include diffuse functions in quantum chemical descriptions of ions, and structures with partial bonding. This concern has been studied in the case of SN2 reactions with ionic nucleophiles.105 Boyd et al. found that SN2 transition states had different geometries when calculations were done with and without diffuse functions, but that the differences in energy between these geometries were negligible in single point calculations including diffuse functions.105 Taken together these data lead us to conclude that the MP2/G3large calculation is adequate for our analysis in this paper. All graphical representations of wavefunctions or geometries shown in this paper were generated using MacMolplot V 7.4.3.106 73 3.3 Results and Discussion 3.3.1 Energies Associated with Nucleofugality, and their Trends Gas phase activation energies (ΔEǂ and ΔHǂ298K) have been calculated at the MP2/G3large level of theory for all alkylating agents found in Scheme 3. These energies are defined in Scheme 2. The alkylating agents studied consisted of 20 methylating agents, including a contingent of sulfonamides, sulfonimides, sulfonates, carboxylate esters, carboxamides, and one carboximide. Additionally, two of the alkylating agents studied were five membered rings which would be opened by the attack of nitrogen, these were 1,3-propanesultone, and N-triflyl-1,3-propanesultam (TPS). Methyl Chloride was run as a convenient reference point with a single atom leaving group. The results of these calculations are displayed in order of ΔEǂ magnitude in figure 18. It was found that most methylating agents had comparable ΔEcomplex energies, which were on the order of 4 – 6 kcal/mol. Carboxamides proved to be an outlier, as they contained a hydrogen bond from the ammonia lone pair to the amide proton, instead of an ammonia proton to oxygen bond. However, the ΔEcomplex should not be relevant to analyses of nucleofugality, and therefore was subtracted out of the activation energy, so that the “activation energy” presented, ΔES→TS, represents the energy difference between the separated species and the transition state of interest. Geometrical parameters of interest from the transition states were tabulated, and can be found in table 3. 74 A) B) Scheme 3 – Relevant energies are derived from electronic structures calculated along the reaction coordinate of an SN2 reaction (A) The difference in energy between a methylating agent in its bound state, and the sum of the separated ions after heterolytic cleavage is defined as the methyl cation affinity (MCA) (B) Methyl cation affinity is defined as the sum of the energies of a leaving group anion and a methyl cation, less the energy of the parent methylating agent (scheme 3).104 Methyl cation affinities appear in table 4, along with a set of experimental and calculated values which appear in the work of Zipse et al. for comparison.104 75 Because the energy of a methyl cation is invariant between methylating species, the methyl cation affinity should depend straightforwardly on the energy of the leaving group anion relative to its methylated counterpart. Methyl cation affinity should therefore give the contribution to ΔHrxn arising directly from anion stability, where methylating agents with lower methyl cation affinities arise from more stable anions. This quantity should also give a trend analogous to ΔEnucleofuge, of Ayers et al. as it shows the change in energy resulting from the leaving event, and can be thought of as the activation energy for the corresponding gas phase SN1 reaction. The ΔES→TS for nitrogen and oxygen derived leaving groups follow an intuitive pattern. Sulfonates have the lowest average ΔES→TS (25.8 kcal/mol), followed by sulfonimides (30.3 kcal/mol) followed by esters (38.7 kcal/mol), followed by sulfonamides (50.3 kcal/mol) followed by amides (58.4 kcal/mol). Nothing in this series challenges conventional thinking, but a few interesting observations can be made. The first of these is simply that while excellent leaving groups can be obtained by adding sulfonyl groups to alcohols, those obtained from the less electronegative amines are significantly and uniformly less reactive, even though a second sulfonyl group may be added to the amine. On average the difference in ΔEǂ between a sulfonate and its sulfonimide analogue (for instance methyl mesylate and methyl MSI) was 4.5 kcal/mol. 76 Scheme 4 – Alkylating agents and the names they are referred to by in this study. 77 Computed Energies of Activation for Menshutkin Alkylation of Ammonia 80 ΔEǂ ΔHǂ ΔE(S→TS) 70 60 50 Energy (kcal/mol) 40 30 20 10 0 Figure 18 – Computed Barrier Heights from the MP2/G3large level of theory. Thermal corrections for the ΔH values were computed at 298K. 78 Table 3 – Calculated ΔES→TS values and Relevant Transition State Geometries rTS(N-C) Å rTS(C-X) Å r0(C-X) Å ΔES→TS kcal/mol % C-X elongation R= CH3 R= OCH3 R= CF3 R= F 1.907 1.926 1.962 1.951 2.000 1.963 1.940 1.944 1.451 1.454 1.459 1.457 31.9 25.7 22.0 23.4 38 35 33 33 R= CH3 R= CF3 R=OCH3 R=CN 1.798 1.858 1.836 1.873 2.088 2.028 2.040 2.016 1.439 1.446 1.440 1.448 45.3 35.5 40.1 33.8 45 40 42 39 1.960 1.899 1.964 1.805 1.840 1.818 2.004 2.050 1.995 2.178 2.121 2.135 1.484 1.475 1.480 1.459 1.467 1.471 26.7 36.8 27.3 53.5 47.8 49.6 35 39 35 49 45 45 R=CH3 R=CF3 R=OCH3 R=CN 1.771 1.809 1.771 1.816 2.199 2.154 2.185 2.146 1.448 1.475 1.448 1.453 65.1 57.2 64.5 55.5 52 46 51 48 Methylsuccinimide 1.779 2.158 1.449 57.0 49 R'= CF3 R'= CH3 R'= F R'= CH3 R'= F R'= F R= SO2CF3 R=SO2CH3 R=SO2F R= H R= H R= CH(CH3)2 79 Table 4 – Methyl Cation Affinity in Experiment and Theory. All values are in kcal/mol. Methyl Cation affinity (Kcal/mol) Cl (-) Br (-) CH3SO3(-) CH3OSO3(-) FSO3(-) CF3SO3(-) CH3CO2(-) CF3CO2(-) CH3OCO2(-) NCCO2(-) CH3C(O)NH(-) CF3C(O)NH(-) CH3OC(O)NH(-) NCC(O)NH(-) (CH3SO2)2N(-) (CF3SO2)2N(-) (FSO2)2N(-) CH3SO2NH(-) FSO2NH(-) CH3SO2NCH(CH3)2(-) MP2/G3large Experiment104 G3104 W1104 225.3 218.0 209.1 201.2 193.2 190.5 238.2 215.8 227.7 210.1 262.4 234.8 258.5 238.1 218.2 192.8 191.6 240.3 227.0 230.6 243.7 228 226.6 227.0 F(-) OH (-) SH (-) PH2 (-) NH3 H2O Mean Absolute Deviation 258.1 276.0 246.3 268.6 104.6 65.4 1.13 258.1 277 246.9 266.7 105 66.7 258.0 276.9 246.6 268.0 104.8 66.0 0.66 258.8 276.8 247.8 269.5 105.4 66.5 0.89 80 It is well known that alkylating agents can be activated by factors such as ring strain and inductive effects, and our series was designed to assess these effects on the barrier height to alkylation. The most familiar activated sulfonates are activated with fluorine, and this is for good reason; the replacement of a methyl group with a trifluoromethyl lowers the barrier by 10. kcal/mol between methyl mesylate and methyl triflate, and 10. kcal/mol between methyl MSI and methyl TFSI. Perhaps the most interesting illustration of the activating power of fluorine is seen in the amides, where trifluoroacetamide has a barrier 7.9 kcal/mol lower than acetamide, while succinimide with an extra carboxyl group is a roughly equivalent 8.1 kcal/mol lower. Halogens are often considered to be π electron donating, however the differences we find on barrier height between a fluorine and a trifluormethane group are modest. Oxygen can also act as an electron withdrawing group by way of the inductive effect so it is unsurprising that we find the barrier for dimethylsulfate 5.9 kcal/mol lower than the barrier for methyl mesylate. The effect of ring strain on alkylation is more difficult to assess in our series, as changing the substitution from methyl to primary alkyl is known to increase the barrier to alkylation for SN2 reactions. It has been recently proposed that this effect is due to weakening of the electrostatic interactions between the alkyl chain and the incoming nucleophile, although steric repulsion remains a popular explanation among organic chemists.107 Calculations done at the B3LYP/631G(d) level of theory estimate the ring strain in 1,3-propanesultone to be 10. kcal/mol, and 9.0 kcal/mol in TPS (see supporting information for more details). While these species are not used for further analysis, we can conclude that the activation of a 5 membered ring for sulfonates and sulfonimides is not enough to counteract the transition from methyl to primary alkyl. Conformations in the Sulfonates are degenerate with regard to an S-C bond rotation, however N-S bond rotations of sulfonimides are capable of producing anti, gauche and syn 81 rotamers with bond rotation. Methyl TFSI and Methyl MSI were found to have minima in the anti and gauche geometries, and transition states were found corresponding to these minima. Methyl FSI did not appear to have a gauche minima, but instead converged toward an eclipsed relationship between the two fluorine substituents this geometry was discarded, and only the anti geometry was used for FSI in this study. Gauche MSI, and TFSI were found to have ΔEǂ values very close in energy to their corresponding anti geometries, but the anti-conformers (lowest minima) were found to lie ~2 kcal/mol and ~6 kcal/mol lower in energy in TFSI and MSI respectively. In order to assess the degree to which the Hammond postulate is obeyed by these Menshutkin reactions we have taken an approach similar to that used by Schlegel et al. for ionic SN2.108-110 These authors defined a % bond elongation (%BE) formula for a similar analysis of the geometries of SN2 transition states.110 We use this formula in our analysis as it is given in equation 21. %BE =100[ rTS(C-X)-r0(C-X)]/r0(C-X) (eq. 21) Where %BE is percent bond elongation, rTS(C-X) is the transition state C-X bond length, and r0(C-X) is the C-X bond length in the isolated species. We found the correlation between %BE of the transition state and the methyl cation affinity to be strong (R2=0.9646, fig. 3B). Schlegel et al. reported that barriers correlate strongly with transition state geometry in the ionic SN2 reaction with simple leaving groups derived from a variety of elements including H, N, C and O.108,109 The dependence of ΔES→TS on %BE in our own work is even stronger than the correlation with methyl cation affinity (R2=0.9813, fig. 3A). 82 With respect to these dependencies, the full set of nitrogen and oxygen derived leaving groups behave as a single set. 3.3.2 On the Fitness of MCA to Describe Inherent Nucleofugality Perhaps the most unexpected and important finding presented here is the quantitatively different relationship between the ΔES→TS and methyl cation affinity between oxygen and nitrogen derived leaving groups. As shown in figure 19, These quantities are strongly correlated within each class of leaving group, but they resolve into distinct groups; with two lines appearing when these energies share the same plot. This discrepancy suggests that there are differences in ΔES→TS that derive solely from the electronic structure of the transition states, which are not captured simply by the differences in energy between methyl bonded and ionized leaving groups. In order to better understand this, analysis was extended to the transition state geometry. Dependance of Barrier Height [ΔE(S→TS)] on Methyl Cation Affinity 80 70 y = 0.5659x - 81.04 R² = 0.9733 60 N Leaving Groups 50 40 ΔE(S→Ts) (kcal/mol) O Leaving Groups 30 y = 0.4953x - 72.172 R² = 0.9743 20 10 0 180 200 220 240 260 280 Methyl Cation Affinity (kcal/mol) Figure 19 – Barrier heights are very well predicted by methyl cation affinities within subsets derived from oxygen and nitrogen, but less so in the full set. Nitrogen leaving groups universally have higher barriers at a given value of MCA. 83 a) Transition State %C-X Elongation vs ΔE(S→TS) ΔE(S→Ts) (kcal/mol) 70 60 50 40 30 20 10 0 y = 2.226x - 51.809 R² = 0.9829 30 35 40 45 50 55 %C-X Bond Elongation b) Transition State %C-X Bond Elongation vs MCA 270 250 230 MCA (kcal/mol) 210 190 y = 3.5619x + 72.261 R² = 0.9659 170 150 30 35 40 45 50 55 %C-X Bond Elongation Figure 20 – Correlations between ΔES→Ts, MCA and bond length. ΔES→Ts correlates very strongly to methyl leaving group bond length, as a percentage of its value in the parent methylating agent at its ground state (a) This is also true for the MCA (b) which shows that our simulated reactions obey the Hammond postulate. 84 While MCA and ΔES→TS both correlate well with %BE (fig. 20), in the transition states of nitrogen derived leaving groups the elongation of the C-X bond is more pronounced relative to shortening of the nascent C-N bond than it was in the oxygen derived leaving groups (fig. 22). This effect is especially noticeable when the bond lengths are compared directly (fig. 22A) but, it remains significant even when the C-N and C-O bonds are normalized via %BE to the lengths of those found in their parent electrophiles (fig. 22B). In nitrogen derived leaving groups the dissociation process of the SN2 is ahead of the displacement process, relative to oxygen. ΔΔEǂ Between Sulfonates and Sulfonimides is Dependant on Correlation 34 32 30 ΔEǂ 28 (kcal/mol) Methylfluorosulfonate 26 MethylFSI 24 22 20 Figure 21 – Dependence of activation energy on theoretical method. At HF/6-31G(d) Methyl FSI and Methylfluorosulfonate have the same activation energy. When the wave function is correlated FSI is found to have a higher activation energy by several kcal/mol. Additional MP2 and CCSD(T) calculations at the MP2(full)/6-31G(d) geometry confirm this trend. Of the leaving groups calculated, only the sulfonimides show a higher activation energy at MP2(full)/6-31G(d) than HF/6-31G(d). 85 a) C-X Bonds in Transition States are Longer When X=N 2.25 2.2 2.15 C-X Bond 2.1 length 2.05 (Å) 2 1.95 1.9 y = -1.002x + 3.9634 R² = 0.9732 Oxygen LG Nitrogen LG y = -0.8834x + 3.671 R² = 0.9805 1.7 1.8 1.9 2 C-N Bond length (Å) b) Transition State % C-X Bond Elongation is More Pronounced When X=N 55 %C-X Bond Elongation Oxygen LG y = -85.575x + 202.45 R² = 0.9745 50 45 Nitrogen LG 40 y = -73.119x + 176.3 R² = 0.988 35 30 1.75 1.8 1.85 1.9 1.95 2 C-N Bond length (Å) Figure 22 – Nitrogen leaving groups exhibit more extensive C-X bond elongation in their transition states than do oxygen groups. This is very apparent when raw bond lengths are compared (a) But this trend holds up even when %C-X elongation is used to correct for the longer C-N bonds present in the parent alkylating agents (b). According to the principle of nonperfect synchronization proposed by Bernasconi, a reaction containing two or more fundamental processes will have a higher inherent barrier if 86 these processes are poorly synchronized than if they are concurrent.111,112 This clearly describes the difference between the transition states of nitrogen and oxygen leaving groups seen in this work; however, why this difference would lead to systematically higher ΔES→TS is difficult to understand. A strong correlation was not observed between the ΔES→TS and the order of either of the partial bonds found at the transition state. A classic case of nonperfect synchronization cited by Bernasconi is the late development of resonance stabilization in the deprotonation of carbon acids.111 An analogy could be drawn between that and the stabilization of the charge on the leaving group. However, we found no indication that the charge is distributed significantly differently between the transition states and the corresponding anions of our methylating agents. A reasonably strong correlation does exist between the natural charge on the leaving group atom at the transition state, and the ΔES→Ts (supporting information). The effect of the nonperfect synchronization in the nitrogen cases could be explained based on this fact, as the nitrogen groups tended to have stronger charges which were more localized on the nitrogen atom. It seems likely that the gap in barriers is explained generally by the fact that the C-N bond had to move further, ionizing almost completely, with less involvement of the nucleophile. Distortions from linearity were observed in the transition states of the nitrogen derived groups which could be explained by this notion. Whereas oxygen derived groups were nearly linear, nitrogen derived groups exhibited N-C-X angles which ranged down to ~173° and correlated moderately well with %BE (supporting information). Additionally, carboxamides and imides formed hydrogen bonds between the carbonyl oxygen and the in-plane hydrogen of the departing methyl fragment. These hydrogen bonds, which appeared to oppose the forward path of the reaction, were not observed in the transition states of esters. 87 Transition State HOMO Energy vs ΔE(S→TS) -0.25 -0.3 EHOMO (h) 10 20 30 40 50 60 70 -0.35 -0.4 -0.45 y = 0.0033x - 0.5203 R² = 0.9263 -0.5 ΔE(S→TS) (kcal/mol) Transition State HOMO Energy vs ΔE(S→TS) -0.25 -0.3 EHOMO (h) -0.35 10 30 50 y = 0.0033x - 0.5115 R² = 0.8939 70 Oxygen Leaving Groups -0.4 -0.45 -0.5 Nitrogen Leaving Groups y = 0.004x - 0.5612 R² = 0.985 ΔE(S→Ts) (kcal/mol) Linear (Nitrogen Leaving Groups) Linear (Oxygen Leaving Groups) Figure 23 – A correlation is evident between the transition state HOMO energy and the magnitude of ΔES→TS. 88 Natural Charge on Leaving Group Atom vs ΔE(S→TS) 0 0 10 20 30 40 50 60 70 -0.5 -1 y = -0.0121x - 0.3365 R² = 0.9051 -1.5 ΔE(S→Ts) (kcal/mol) Natural Charge on Leaving Group Atom vs ΔE(S→TS) 0 0 -0.5 20 40 60 80 y = -0.0126x - 0.302 R² = 0.875 N LG O LG Linear (N LG) -1 -1.5 y = -0.012x - 0.3511 R² = 0.9251 Linear (O LG) ΔE(S→TS) (kcal/mol) Figure 24 – Natural charge on the leaving group atom correlates with ΔES→TS. Additional support for rationalizing these results can be found in the work of Shaik et al. who have developed models for understanding kinetic barriers using concepts from valence bond (VB) theory.113,114 The central theme of their work is the view of a transition state as an avoided crossing between the ground states and high energy vertically excited states.113 Ionic character may play a role in one or both of these representations.113 A correlation diagram can be constructed including the reactant and product complexes in which lines are drawn from the high energy VB states to the product ground states (and vice versa) and the center point is defined as the crossing.113 The activation energy can then be given as ΔE‡= ΔEc-B where ΔEc is the energy 89 at the crossing, and B is “quantum mechanical resonance energy” which results from mixing between different valence bond representations of the transition state.113,114 Factors influencing B were studied for SN2 transition states including H3(-) and CH5(-) and in both cases it was found that B was at its highest (i.e. lowest activation energy) when the angle corresponding to the reaction coordinate was 180°, and decreased with as the angle became more accute.114 Additionally B decreases when the bond lengths of the forming and breaking bond increase.114 Both effects were attributed to a destabilizing increase in the amount of ionic character present in the transition state.114 These findings seem consistent with our own observations, and might imply a causal relationship between the relatively loose and bent transition states of nitrogen centered nucleofuges, and their higher barriers. %BE vs. N-C-X Angle at the Transition State of Menshutkin Reactions 181.00 y = 0.0204x + 178.36 Oxygen LG 180.00 R² = 0.1044 179.00 178.00 N-C-X angle 177.00 (degrees) 176.00 175.00 174.00 173.00 172.00 Nitrogen LG y = -0.3441x + 191.64 R² = 0.8229 25 35 45 55 65 % C-X Bond Elongation Figure 25 – The transition states of nitrogen leaving groups become progressively more bent as C-X bond gets longer. No such trend occurs in oxygen leaving groups. A separate phenomenon is evident in the difference between sulfonates and sulfonimides. Two of the three sulfonimides (methyl TFSI and methyl FSI) had comparable 90 barriers to their sulfonate analogues at the HF/6-31G(d) level of theory; the ΔEǂ values of methylfluorosulfonate and methylFSI differed by only 0.03 kcal/mol. When the geometries are reoptimized using MP2(full)/6-31G(d) we find that the difference has expanded to 4.3 kcal/mol. In order to exclude the possibility of an artifact in the MP2 calculation, the barriers to alkylation in methylfluorosulfonate and methylFSI were calculated using two coupled cluster calculations,115-117 CCSD(T)/6-31G(d) and CCSD(T)/6-31+G(2d,p) at the MP2(full)/6-31G(d) geometry. These calculations affirm the difference, with the CCSD(T)/6-31+G(2d,p) showing a ΔΔEǂ of 5.1 kcal/mol, whereas the ΔΔEǂ for the MP2/G3large (the single point calculation without vibrational correction) was 5.4 kcal/mol. (fig. 21) We also note that while differences are present in the methyl cation affinities of sulfonates and sulfonimides, they are not systematic. The change in activation energy in sulfonimides that we observe occurs concurrently with a geometric perturbation. The nitrogen atoms of sulfonimide groups are nearly planar at HF/631G(d), whereas they become mildly pyramidal at MP2(full)/6-31G(d). A similar, but more dramatic effect is noticeable in sulfonamides, where FSA and MSA are basically tetrahedral at MP2(full)/6-31G(d), and MSA is significantly pyramidal at HF/6-31G(d) (see table 5). When an isopropyl group is introduced onto the sulfonamide in the case of MeiprFSA, the pyramidalization effect is somewhat retarded, but not as much as in the case of Methyl FSI with two sulfonyl groups. 91 HF/6-31G(d) MP2(full)/6-31G(d) E= - 0.530 h E= - 0.525 h HOMO-5 E= - 0.530 h E= - 0.527 h HOMO-6 Figure 26 – Some origins in the gap between the nucleofugality of sulfonimide and sulfonate leaving groups can be linked to differences in the electronic structure. Imide spanning orbitals such as HOMO-5 in FSI ( Top Left) have better overlap in the planar HF/6-31G(d) geometry ( left) In the MP2(full)/6-31G(d) geometry (Right) HOMO-5 and HOMO-6 mix. Presumably these bonding interactions are opposed by n → σ* interactions localized to one sulfonyl group or the other. The above observations suggest that orbital interaction between the nitrogen atom and the two sulfonyl groups are preventing a pyramidalization analogous to that which occurs when only one is present. Sulfonyl groups have been well studied, and it is commonly been concluded that hyperconjugative nN→σ* interactions with the S-O bond, delocalize electrons in the sulfonyl group.118,119 Additionally, it has been shown that sulfamidates, which have a negatively charged sulfonamide bound to a nitrogen cation, have sulfonyl oxygens that form significantly stronger 92 hydrogen bonds than do sulfonamides, or even the usually more basic sulfones and sulfoxides.120 This suggests an explanation for the drive to pyramidalization as sulfonamide derived species ionize: a pyramidal geometry at nitrogen facilitates better overlap in the n→σ* conjugation, but when two sulfonyl groups are present, ideal interaction with each is not possible. While the size of the sulfonimide wave functions and the relative ambiguity of their frontier orbitals make a full accounting of this phenomenon difficult, a convincing example of this is illustrated in figure 23, in the HOMO-5 and HOMO-6 energy levels of the FSI transition state. In the HF/6-31G(d) structure, HOMO-5 contains a bonding orbital that spans the length of the imide moiety, whereas at MP2(full)/6-31G(d), mixing occurs between HOMO-5 and HOMO-6, destabilizing both orbitals. Table 5 – Transition State Pyramidalization in Sulfonamide Species at HF and MP2 geometries (all values are given in degrees). HF/6-31G(d) MP2(full)/6-31G(d) Dihedral (S-N-R-C) Dihedral (S-N-R-C) Angle(S-N-R) Methyl FSI 178.86 161.00 121.39 Methyl FSA 174.97 126.36 109.31 Methyl MSI 178.83 169.65 121.89 Methyl MSA 132.05 121.27 107.27 Meipr FSA 177.83 134.43 119.9 A literature precedent does exist for the dependence of intrinsic the barrier of SN2 reactions on the leaving group atom. Hoz et al. used G2 derived calculations to study symmetrical anionic SN2 reactions and concluded that the intrinsic barrier changes between groups of the periodic table, and stays relatively constant within them, up until the border 93 between metals and non-metals.121 Nitrogen and oxygen had intrinsic barriers of 29.3 and 19.5 kcal/mol respectively, whereas the halogens clustered near 10 kcal/mol.121 This inherent difference was then shown to extend to similar SN2 displacements occurring at nitrogen.122 In this work we have shown that these findings generalize beyond symmetric, charged variants of the SN2, and rationalize them within the context of our systems of interest. 3.4 Conclusion The ΔES→TS of nitrogen and oxygen derived leaving groups in the Menshutkin reaction correlate well with the thermodynamic stability of the ions, as determined by MCA, differences exist between the two classes. These differences are rooted in the synchronization of the events inherent in the SN2 process, as well as geometric limitations on the efficiency of activating groups on nitrogen. This finding is relevant to recent work on indices of nucleofugality, because it shows that complicating factors may exist which are relevant to the dissociation of a nucleofuge, but are not directly related to the stability of the fully dissociated group. 94 4 4.1 Chapter 4: Summary and Future Study Summary In summary, two significant findings have come from my research and have been described in this work. The first concerns the effect of triazoles on the conductivity of lithium ion electrolytes. Model compounds were synthesized which contained increasing numbers of triazoles per ether oxygen. It was found that increasing the number of triazoles in the material increased the glass transition temperature, which was inversely proportional to room temperature conductivity. Increasing the proportion of triazoles also lead to crystallization behavior which enable us to obtain a single crystal X-ray structure of one of our model compounds, 6EO2T. Ab initio calculations showed that tetra coordinate solvent shells containing a triazole have roughly the same energy as those which do not contain triazoles, which led implies another explanation for the effect of triazoles on conductivity. A second effect triazoles were observed to have on temperature dependant conductivity was the induction of compensation behavior, whereby the Arrhenius pre-exponential factor has an approximately exponential dependence on the activation energy. We rationalize our data by invoking the polarity of the traizole which has been shown in other studies to affect the Arrhenius pre-exponential factor of transport processes in polar liquids. Additionally, our crystal structure showed dipole-dipole interactions between triazole moieties which shows how dipoles are most likely enhancing the glass transition temperature and the activation energy of conductivity. 95 A second study probed the nuclefugality of polyatomic oxygen and nitrogen derived leaving groups. By optimizing the transition states of Menshutkin reactions, and calculating the methyl cation affinities of the same species, we have been able to pinpoint a difference in the nucleofugality between these sets of leaving groups that relies on transition state organization rather than anion stability. The inherent differences between polyatomic oxygen and nitrogen leaving groups seem to stem from a few different factors. The first factor is the non-linearity of the nitrogen nucleofuge transition states relative to those of oxygen nucleofuges. This distortion has been attributed to a less effective delocalization of electron density, and thus a higher energy in other work. A second difference arises from the preferred geometry of sulfonamides during the leaving process. Sulfonamides show a tendancy to pyramidalize during the leaving process which can most likely be attributed to stabilization via n→σ* interactions from the nitrogen to the sulfur. When a second sulfonyl group is added, pyramidalization becomes less favorable due to the presence of orbitals whose lowest energy results from a planar geometry at nitrogen. The effect of this is that a second sulfonyl group becomes less effective at activating nitrogen as a nucleofuge than the first sulfonyl. These findings raise additional questions, which might be addressed by other researchers, or myself at a later time in my career. These will be expounded in the two sections that follow. 96 4.2 Future Directions for CUAAC Derived Lithium Single Ion Conductors The effects exerted by the triazole on the conductivity of lithium ion salt complexes are interesting from a mechanistic standpoint, however the study described here did not demonstrate any useful consequences of this behavior. Frech et al. actually proposed that the synthesis of highly polar electrolyte materials aimed at increasing the Arrhenius pre-exponential term might be a productive way to increase the conductivity of electrolytes for batteries;72 however, my work has inadvertently shown a limitation of this approach. However if my explanation for compensation behavior is correct, then the triazoles are activating and impeding the conductivity of electrolyte materials through different mechanisms, and this fact could be manipulated to improve single ion conductor materials. Des Marteau and Borodin et al. showed earlier that ionic correlation is a problem for lithium single ion conductors, affecting the chain to chain transfer time of the lithium ion in these materials as well as the ability of the materials to transport charge through co-diffusion of the lithium with the chain.20 A possible mechanism for enhancing the conductivity of lithium electrolytes might be the enhancement of local dipole density in the region of the anion moiety. In order to keep the overall concentration of triazoles in the material relatively low this would mean the introduction of one triazole near an anion moiety (19). Materials of nearly identical composition (22) but lacking triazoles would be used as controls (Scheme 5). 97 Scheme 5 – Proposed materials and synthesis for the investigation of triazoles as an activating moiety in lithium single ion conductors. 98 The PEG starting materials used for materials 19 and 22 could be in the range of Mn= 300 – 1000, and the study would probably benefit from the synthesis and testing of several chain lengths. Shorter PEG materials are technically easier due to the fact that PEG becomes waxy around Mn= 600 and its solubility in organic solvents diminishes as molecular weight increases. Additionally blends of 19 and 22 with PEGDME 500 might be worth testing as neat materials would have high concentrations of ions. Internal data to the Baker group has shown that PEGDME 500 complexes with LiTFSI show the highest conductivity when they contain roughly 1 lithium per 32 ether oxygens.4 The proposed single ion conductors could have several times that concentration of lithium depending on the chain length. In the event that useful data comes from this project, these systems should be modeled using molecular dynamics simulations in order to better understand the nature of the activation. Modeling lithium ion transport is tricky and requires a specialized polarizable force field. Rather than modeling ourselves, I believe it would be advantageous to approach Oleg Borodin about a collaboration.17 4.3 Future Directions for Studies of Nucleofugality in Activated Leaving Groups In chapter 3 we showed that inherent differences exist between the Nucleofugality of polyatomic oxygen and nitrogen derived leaving groups using computational methods. The obvious next step for this work would be to continue exploring different classes of leaving groups using similar computational methods. The first group that might be fruitful would be polyatomic carbon leaving groups. Polyatomic carbon leaving groups are interesting, because carbon acids are known with pKa values of less than 10, however carbon nucleofuges are extremely rare in any other context. Polyatomic carbon leaving groups might prove more viable than expected, or similar problems might be observed to those seen in nitrogen nucleofuges. 99 An additional set of leaving groups which might be interesting to look at would be positively charged ammonium leaving groups in comparison with negatively charged borates and borohydrides. These compounds might be an interesting comparision, as the initial electronic structures should be quite similar, however they lead to quite different outcomes. 100 APPENDICES 101 4.4 Appendix 1 – Additional Study of TPS Introduction The Synthesis of TPS was a part of an effort to make stable triple ion type ionic liquids, similar to those of Ohno et al.124-126 Synthesis of TPS was accomplished in four steps from 1,3 propanesultone, and proceeded mostly through known materials. TPS itself was not a known material and has been fully characterized, including single crystal X-Ray Diffraction. While most of the synthetic work shown is derived from literature protocols,127-129 the final step required extensive independent optimization and is not a trivial procedure. A variety of bases and running times were tried, however Hünig’s base worked best, under the conditions described below. This choice was partially informed by the literature synthesis of similar compounds.130 X-Ray section is courtesy of Dr. Richard Staples. Single crystal geometric data was compared with a geometric optimization of the TPS structure at MP2(full)/6-31G(d) and the two were found to be in good agreement. 102 Synthesis of TPS Scheme 6 – Synthetic Route from 1,3 Propane sultone to TPS. 3-Chloropropane-1-sulfonyl chloride 1127 To an oven dried round bottom flask were added 50g (0.41 mol) 1,3-propanesultone, 100g (0.84 mol) thionyl chloride, and 0.25 g dimethylformamide (3.4 mmol). A jacketed condenser and drying tube containing anhydrous calcium chloride pellets were affixed to the round bottomed flask, which was then heated to reflux at 75°C (oil bath temperature). The flask was allowed to reflux over night after which point it was cooled, and a short path distillation apparatus replaced the condenser. Excess thionyl chloride and byproducts were removed by distillation (Vapor T = 73°C). Product 1 was purified by distillation under reduced pressure. Two fractions were collected, the first of which had a Tvap= 60°C at P = 9.7 Torr. This fraction reacted vigorously with water and contained very little hydrogen when analyzed by NMR, this was believed to be mostly a mixture of chlorosulfinic acid, and chlorosulfinic anhydride. A second fraction had a Tvap=105°C at P = 898 mTorr; this proved to be product 1, which was obtained as a tan liquid in 98% yield (69.5g) and stored under nitrogen. Compound was confirmed by comparison to data in 103 (1) and publicly available spectra from Sigma Aldrich. 1H NMR (600MHz) (CDCl3) δ= 2.49 (m, 2H, CH2CH2CH2) 3.70 (dd, 2H, CH2CH2S(O)2, J=6.2, 6.2 Hz) 3.84 (dd, 2H, ClCH2CH2, J=7.5, 7.5 Hz). 13C NMR (CDCl3) δ= 30.01, 44.18, 65.06. 3-Chloropropane-1-sulfonamide 2127 To an oven dried three neck round bottom flask were added 10g (0.056 mol) 1 and 250 mL dichloromethane, which had been freshly distilled off of calcium hydride to insure dryness. The flask was cooled on an ice salt bath which was kept at a temperature at or below -5°C for the duration of the reaction. The flask was initially shielded from water through use of a nitrogen line. An aspirator and bubbler were affixed to the flask to facilitate the introduction of ammonia gas. Anhydrous ammonia gas was then bubbled through the reaction for one hour with continuous stirring using a Teflon coated stirbar. White precipitate developed in the flask. After the ammonia cylinder was disconnected, the reaction was allowed to stir for an additional forty five minutes to insure completion. Ammonium chloride was removed by gravity filtration, and rinsed with acetonitrile. Crude product was concentrated on a rotovap. Pure 3-chloropropane-1sulfonamide was obtained by recrystallization from chloroform in 91% yield (8.2g). The product was a colorless solid. mp= 62 - 65°C 1H NMR (600 MHz) (CD3CN) δ= 2.22 (m, 2H, CH2CH2CH2) 3.20 (dd, 2H, CH2CH2S(O)2, J=7.6, 7.6 Hz) 3.72(t, 2H, ClCH2CH2, J=6.4 Hz) 5.35 (broad singlet, 2H, S(O)2NH2) 13C NMR (CD3CN) δ= 29.82, 45.79, 54.61. 104 1,3-Propanesultam 3127 Absolute ethanol (150 mL) was added to a rigorously dried round bottom flask and sparged with dry nitrogen for 5 – 10 min to remove oxygen. The solvent was cooled on an ice bath, and then 5.08g NaH in 60% dispersion with mineral oil (0.127 mol NaH) were added to the ethanol in pieces. Once alkoxide generation was complete 20g (0.127 mol) 2 were added as a solution in 625 mL absolute ethanol. The reaction mixture was protected with a condenser and a calcium chloride drying tube, and refluxed overnight until high conversion was evident in NMR. Ethanol was removed by rotovap, and reaction mixture was dissolved in chloroform and filtered, then dried over sodium sulfate. Sodium chloride produced in the reaction was washed with additional chloroform. Product was purified by distillation under reduced pressure (Tvap= 179 °C, P=629 mTorr) however mineral oil codistilled. Mineral oil was removed by washing the product with hexanes. Product was then dissolved in dichloromethane and dried over Sodium Sulfate to remove excess water. Product was obtained in 79% yield (12.1g) as a light yellow oil. Method used is similar to that of King et al. (127). Product confirmed by comparison to data of Askin et al. (128) 1H NMR (500 MHz) (CDCl3) δ= 2.39 (p, 2H, CH2CH2CH2, J=7.2 Hz) 3.03 (t, 2H, NHCH2CH2, J=7.6 Hz) 3.36 (t, 2H, CH2CH2SO2, J= 6.9 Hz) 4.55 (broad singlet, 1H, SO2NHCH2) 13C NMR δ= 24.10, 42.36, 46.73. N-triflylpropanesultam (TPS) 4 0.5 g (4.1 mmol) 3 where added to a rigorously dry round bottom flask equipped with a teflon coated stir bar. A 10 mL addition funnel was added and placed on a nitrogen line to shield the reaction from water. The round bottom flask was cooled on a dry ice acetone bath. Following 105 cooling, 1.5 mL (8.9 mmol) of trifluoromethanesulfonyl anhydride were added to 8 mL of freshly distilled rigorously dried dichloromethane, which were added to the flask and allowed to cool. An aliquot of 0.71 mL (4.1 mmol) diisopropylethylamine was then added to an additional 8 mL of dichloromethane in the addition funnel. The resulting solution was added dropwise over a period of roughly five minutes. After the reagents were combined, the bath was removed, and the flask allowed to equilibrate to room temperature. The color of the solution gradually darkened until it was an opaque jet black. The reaction was allowed to stir for roughly 48 hours, after which, 10 mL distilled water were added. The biphasic mixture was transferred to a separatory funnel, and after separation the aqueous phase was extracted with 2 aliquots of 15 mL dichloromethane. The organic phase was dried of sodium sulfate, and concentrated with a rotovap to yield darkly colored and tarry crude solids. The crude product was sublimed (p = 668 mTorr, Bath T = 100°C) to yield a white crystalline solid in 65% yield (0.67g). Crystals were grown for single crystal X-Ray study by slow evaporation from Toluene. Compound is previously unknown. mp=111-115°C HRMS [M-H]- Calculated: 251.9612 Measured: 251.9604 ppm: -3.2. 1H NMR (CD3OD) (600 MHz) δ= 2.50 (p, 2H, CH2CH2CH2, J= 6.6 Hz) 3.66 (t, 2H, SO2CH2CH2, J= 7.3) 4.00 (t, 2H, (SO2)2NCH2CH2, J= 6.8 Hz) 13C NMR, (600 MHz) (CD3CN) δ= 19.10, 48.88, 50.15, 119.47 (q, CF3, J= 323 Hz) IR (KCl Pellet) cm-1= 3022, 2965, 1478, 1403, 1387, 1347, 1325, 1283, 1237, 1204, 1177, 1149, 1133, 1070, 1045, 1014, 980, 851, 727, 661, 600, 575, 552, 499, 449, 427, 403. 106 Crystallography of TPS Experimental Section A colorless plate crystal with dimensions 0.30 x 0.27 x 0.03 mm was mounted on a Nylon loop using very small amount of paratone oil. Data were collected using a Bruker CCD (charge coupled device) based diffractometer equipped with an Oxford Cryostream low-temperature apparatus operating at 173 K. Data were measured using omega and phi scans of 1.0° per frame for 30 s. The total number of images was based on results from the program COSMO74 where redundancy was expected to be 4.0 and completeness to 0.83 Å to 100%. Cell parameters were retrieved using APEX II software75 and refined using SAINT on all observed reflections. Data reduction was performed using the SAINT software76 which corrects for Lp. Scaling and absorption corrections were applied using SADABS77 multiscan technique, supplied by George Sheldrick. The structures are solved by the direct method using the SHELXS-97 program and refined by least squares method on F2, SHELXL-975, which are incorporated in OLEX2.77 The structure was solved in the space group P21/c(no. 14). All non-hydrogen atoms are refined anisotropically. Hydrogens were calculated by geometrical methods and refined as a riding model. All drawings are done at 50% ellipsoids. Acknowledgement. The CCD based x-ray diffractometer at Michigan State University were upgraded and/or replaced by departmental funds. 107 Table 6 – Crystal Data and Structure Refinement for TPS Identification code nej413 Empirical formula C4H6F3NO4S2 Formula weight 253.22 Temperature/K 173.0 Crystal system monoclinic Space group P21/c a/Å 13.9496(7) b/Å 5.9882(3) c/Å 10.5155(5) α/° 90 β/° 92.202(3) γ/° 90 3 Volume/Å 877.74(7) Z 4 3 ρcalcmg/mm 1.916 -1 m/mm 6.009 F(000) 512.0 3 Crystal size/mm 0.296 × 0.269 × 0.034 2Θ range for data collection 6.34 to 144.042° Index ranges -16 ≤ h ≤ 16, -7 ≤ k ≤ 7, -11 ≤ l ≤ 12 Reflections collected 6768 Independent reflections 1675[R(int) = 0.0742] Data/restraints/parameters 1675/0/127 2 Goodness-of-fit on F 1.140 Final R indexes [I>=2σ (I)] R1 = 0.0681, wR2 = 0.1893 Final R indexes [all data] R1 = 0.0812, wR2 = 0.1993 -3 Largest diff. peak/hole / e Å 0.85/-0.45 108 a) b) Figure 27 – The crystal structure of TPS. A view of a single molecule is shown in part a with thermal elipsoids shown at 50% probability. The packing along the b axis of the crystal is also shown (b). 109 Table 7 – Comparison Between the Crystal Geometry of TPS and Geometry at MP2(full)/631G(d) (Bond Lengths) Bond Lengths for TPS. Atom Atom Experiment/Å S1 O3 1.410(4) S1 O4 1.412(5) S1 N1 1.621(5) S1 C4 1.843(6) S2 O1 1.426(5) S2 O2 1.428(5) S2 N1 1.715(4) S2 C1 1.757(5) F1 C4 1.303(8) F2 C4 1.297(8) F3 C4 1.310(8) N1 C3 1.483(7) C1 C2 1.524(8) C2 C3 1.517(8) Calculated/Å 1.450 1.455 1.653 1.840 1.454 1.459 1.754 1.789 1.330 1.334 1.345 1.475 1.519 1.528 110 Deviation/Å 0.040 0.043 0.032 -0.003 0.028 0.031 0.039 0.032 0.027 0.037 0.035 -0.008 -0.005 0.011 Table 8 – Comparison Between the Crystal Geometry of TPS and Geometry at MP2(full)/631G(d) (Bond Angles) Bond Angles for TPS. Atom Atom Atom O3 S1 O4 O3 S1 N1 O3 S1 C4 O4 S1 N1 O4 S1 C4 N1 S1 C4 O1 S2 O2 O1 S2 N1 O1 S2 C1 O2 S2 N1 O2 S2 C1 N1 S2 C1 S1 N1 S2 C3 N1 S1 C3 N1 S2 C2 C1 S2 C3 C2 C1 N1 C3 C2 F1 C4 S1 F1 C4 F3 F2 C4 S1 F2 C4 F1 F2 C4 F3 F3 C4 S1 Experiment/° 121.8(3) 108.3(2) 107.0(3) 109.9(3) 105.1(3) 103.1(3) 118.0(3) 108.0(3) 111.4(3) 110.0(3) 113.8(3) 92.6(2) 122.0(3) 124.0(4) 113.9(4) 103.9(4) 107.4(4) 104.7(4) 110.4(4) 107.4(6) 108.9(5) 110.5(6) 110.2(6) 109.3(4) 111 Calculated/° 124.8 109.0 106.1 107.4 105.6 101.6 121.4 110.3 112.0 108.6 109.7 90.4 123.8 121.7 114.5 104.4 106.0 104.4 110.2 109.1 109.1 109.8 109.1 109.4 Deviation/° 3.0 0.7 -0.9 -2.5 0.5 -1.5 3.4 2.3 0.6 -1.4 -4.1 -2.2 1.8 -2.3 0.6 0.5 -1.4 -0.3 -0.2 1.7 0.2 -0.7 -1.1 0.1 Estimation of Ring Strain in TPS† Ring strain was calculated for 1,3-Propanesultone and N-Triflylpropanesultam using the following homeodesmotic reactions seen in figure 25. Figure 28 – Homeodesmotic reactions used to calculate the strain energy of sulfonyl herterocycles. Structures were minimized at the B3LYP/6-31G(d) level of theory in GAMESS using the DFT=B3LYP keyword (as opposed to the slightly different DFT=B3LYP1 version). Ring strain was estimated to be 10.2 kcal/mol in 1,3-Propanesultone, and 9.0 kcal/mol in Ntriflylpropanesultam. † This page is a republication of data from the supporting information of Spahlinger, G.; Jackson J. E. Phys. Chem. Chem. Phys. 2014, 16, 24559 – 24569. It has been republished with permission from the PCCP Owner Societies. The original article may be found online at the following link: http://pubs.rsc.org/en/content/articlelanding/2014/cp/c4cp03741c#!divAbstract 112 4.5 Appendix 2 – Spectal Data and Geometric Results from Computations This section contains annotated proton and carbon 13 NMR spectra from the compounds appearing in this work which had not previously been synthesized. Labels have been added to the spectra to show how the 1H and 13C atoms in the proposed structure correspond to the lines in the specra. Additionally, output geometries have been provided for geometric optimizations of compounds whose electronic structures or energies were analyzed in chapters 2 and 3 at the relevant levels of theory. All structures described were first optimized in C1 symmetry. The structures described in Chapter 3 were scrutinized carefully for possible symmetry, and rerun in the highest Abelian point group they seemed to be capable of converging to. Point groups given for this set should be considered the highest symmetry in the converged structures. Structures in chapter 2 were not rerun to confirm symmetry. Although some structures appeared to be converging to higher symmetries, the point group in these calculations is assumed to be C1. 113 Annotated 1H and 13C Spectra of Selected Compounds 1 H 13 C Figure 29 - 6EO2T 114 1 H 13 C Figure 30 - 8EO2T 115 1H 13 C Figure 31 - 6EO1T 116 1 H 13 C Figure 32 - 8EO1T 117 1 H (Methanol d4) 13 C (Acetonitrile d3) Figure 33 - N-Triflylpropanesultam (TPS) 118 MP2(full)/6-31G(d) Geometries and Energies of Simulated Solvent Shells from G3MP2 Calculations with and without a Bound Lithium Cation. Table 9 - Glyme, Energy: -307.87678 C C O O C C H H H H H H H H H H 6 6 8 8 6 6 1 1 1 1 1 1 1 1 1 1 0.641616 -0.641616 1.708579 -1.708579 2.965284 -2.965284 0.677787 0.677787 -0.677787 -0.677787 3.090045 3.726478 3.090045 -3.726478 -3.090045 -3.090046 0.399513 -0.399513 -0.531639 0.531639 0.120394 -0.120394 1.045847 1.045847 -1.045847 -1.045847 0.749078 -0.660232 0.749080 0.660232 -0.749080 -0.749078 0.000000 0.000000 0.000000 0.000000 0.000000 0.000000 -0.889262 0.889261 -0.889262 0.889262 0.891947 0.000000 -0.891945 -0.000001 -0.891946 0.891947 Table 10 - Glyme-(Li+), Complex Energy: -315.22669 C C O O C C Li H H H H H H H H H H 6 6 8 8 6 6 3 1 1 1 1 1 1 1 1 1 1 -0.714327 0.714326 -1.313495 1.313495 -2.748016 2.748017 0.000000 -1.258219 -0.765347 1.258219 0.765346 -3.101517 -3.196376 -2.996115 3.101517 3.196376 2.996116 -0.912652 -0.912652 0.329428 0.329428 0.336643 0.336643 1.676941 -1.755075 -0.984161 -1.755075 -0.984162 1.313806 -0.442621 0.173268 1.313806 -0.442621 0.173267 119 0.242036 -0.242036 -0.182073 0.182072 -0.002444 0.002445 0.000000 -0.198903 1.334828 0.198903 -1.334828 -0.326419 -0.621636 1.049427 0.326419 0.621638 -1.049426 Table 11 - Glyme + DME, Energy: -462.40188 C C O C O C C O C H H H H H H H H H H H H H H H H 6 6 8 6 8 6 6 8 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -2.749443 -1.845247 -1.561499 -0.549944 -0.019917 1.225974 1.555618 2.121614 1.757107 -2.445309 -3.380290 -3.333940 -2.473329 -2.388798 -0.747625 0.158084 1.575174 1.110864 1.954637 1.851353 0.462493 1.939401 2.253954 2.102877 0.674491 -1.340694 0.557657 -0.671012 1.268741 1.755734 2.402627 -1.936414 -0.852544 -0.922555 -2.270828 -1.570933 -0.739570 1.195884 0.373054 2.102893 0.580776 2.741666 3.273207 1.710349 -1.813572 -1.933950 -2.898355 -0.090417 -1.866106 -0.827695 120 -0.536394 0.498539 -0.151179 0.790593 -0.427915 -0.211788 0.955154 0.236125 -1.137342 -1.016968 0.333246 -1.245194 -0.140051 1.439571 1.485212 1.269913 -1.187951 0.449661 0.223281 1.998419 0.875308 0.586107 -1.636383 -1.583124 -1.259858 Table 12 - Glyme-(Li+)-DME, Energy: -469.796041 O H C C C O C Li O C C C C C C C C C C C C C C C C C 8 1 6 6 6 8 6 3 8 6 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1.066685 3.150957 2.299057 1.017221 2.299057 1.066687 1.017225 -0.327147 -2.199003 -3.007060 -3.007069 2.356559 2.356555 3.150959 0.044734 1.129833 1.809283 -2.326282 -3.634586 -3.632522 -2.326297 -3.634614 -3.632511 0.044727 1.809276 1.129831 -1.317252 -1.263785 -0.700824 -2.716841 0.700822 1.317252 2.716841 0.000001 -0.000005 -0.604703 0.604707 -0.692824 0.692822 1.263782 3.083454 2.850156 3.253161 -1.034589 0.153422 -1.389995 1.034583 -0.153408 1.390008 -3.083452 -3.253163 -2.850155 121 0.133927 0.121744 -0.276792 -0.205224 0.276794 -0.133929 0.205221 -0.000004 -0.000004 1.026706 -1.026700 -1.372322 1.372325 -0.121739 -0.118649 1.285009 -0.322316 1.760995 1.502159 0.594504 -1.761001 -1.502142 -0.594486 0.118643 0.322315 -1.285011 Table 13 - Glyme + Glyme, Energy: -615.75824 C O C C O C C O C C O C H H H H H H H H H H H H H H H H H H H H 6 8 6 6 8 6 6 8 6 6 8 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -4.341091 -3.010677 -2.943020 -1.485976 -1.373980 -0.036362 0.046079 1.356048 1.506729 2.925895 3.028982 4.327327 -4.303736 -4.764751 -4.988097 -3.539637 -3.320992 -0.899511 -1.119520 -0.004200 0.668541 0.264864 -0.023711 -0.720045 -0.133035 1.306699 0.812237 3.135992 3.636004 4.322004 4.582947 5.087476 1.058400 0.628004 -0.775380 -1.103986 -2.501374 -2.860332 2.870331 2.502812 1.096719 0.777455 -0.637976 -1.058707 2.138367 0.586363 0.828745 -1.079653 -1.319710 -0.775052 -0.556357 -3.949457 -2.496106 -2.450036 3.953379 2.387047 2.596278 0.679006 0.625964 1.205549 1.214618 -2.148990 -0.704949 -0.693743 122 -0.559869 -0.331164 -0.130095 0.095384 0.279006 0.593603 0.614345 0.207230 0.214243 -0.193210 -0.215615 -0.595780 -0.704640 -1.456178 0.297166 0.742065 -1.007591 -0.773864 0.976275 0.634485 -0.164540 1.566771 0.508708 -0.005489 1.663031 1.212786 -0.493121 -1.184065 0.523637 -0.587054 -1.603428 0.107663 Table 14 - Glyme-(Li+)-Glyme, Energy: -623.18874 O H C C C H O H C Li O C C H H H H H H H C H H H H H H H O C H H H 8 1 6 6 6 1 8 1 6 3 8 6 6 1 1 1 1 1 1 1 6 1 1 1 1 1 1 1 8 6 1 1 1 1.435719 3.519662 2.659720 1.342860 2.659693 -3.519644 1.435677 -2.703904 1.342759 0.000000 -1.435694 -2.659703 -1.342800 2.703921 2.703877 3.519622 0.379570 1.397517 2.148514 -2.703894 -2.659708 -3.519638 -0.379614 -2.148562 -1.397566 0.379678 2.148630 1.397641 -1.435700 -1.342821 -0.379635 -1.397595 -2.148584 1.094065 1.027054 0.350627 1.869429 -0.350662 0.742019 -1.094080 1.489831 -1.869436 0.000010 -0.743058 -0.666676 -1.950062 -0.374332 0.374296 -1.027102 -2.376120 -1.218377 -2.607238 -1.489819 0.666688 -0.742012 -1.921332 -1.983819 -2.828049 2.376129 2.607217 1.218373 0.743080 1.950082 1.921361 2.828071 1.983827 123 0.743055 0.741968 0.666653 1.950054 -0.666707 -1.027058 -0.743068 0.374338 -1.950066 0.000009 1.094081 0.350655 1.869432 1.489800 -1.489855 -0.742051 -1.921319 -2.828058 -1.983832 -0.374309 -0.350626 1.027088 2.376123 2.607227 1.218368 1.921341 1.983784 2.828046 -1.094054 -1.869409 -2.376102 -1.218349 -2.607203 Table 15 - 4-Methoxymethyl-1,2,3-Triazole, Energy: -394.90167 N C C N N H C O C H H H H H H 7 6 6 7 7 1 6 8 6 1 1 1 1 1 1 -1.400475 -0.370011 -0.870993 -2.211938 -2.547851 -2.954152 1.054389 1.855637 3.236678 -0.398586 1.263739 1.263351 3.778956 3.511352 3.511718 -1.159229 -0.272576 1.014156 0.822928 -0.485243 1.513956 -0.709306 0.460258 0.138116 1.983562 -1.326018 -1.330141 1.083722 -0.437107 -0.441570 -0.000539 0.000493 0.000896 0.000018 -0.000823 -0.000173 0.001325 -0.001432 -0.000326 0.001496 0.889093 -0.883638 -0.002585 0.893653 -0.891301 Table 16 - 4-Methoxymethyl-1,2,3-Triazole-(Li+), Energy: -402.25682 N C C N N H C O C Li H H H H H H 7 6 6 7 7 1 6 8 6 3 1 1 1 1 1 1 -0.748360 -0.438595 -1.624808 -2.572931 -2.069208 -3.585893 0.989591 1.813108 3.219080 0.889872 -1.857168 1.218020 1.218006 3.767261 3.463803 3.463385 0.891048 -0.433561 -1.145612 -0.181222 1.059394 -0.288401 -0.878671 0.300586 -0.035633 1.977293 -2.200787 -1.477338 -1.479360 0.904859 -0.608513 -0.610704 124 0.000537 0.000293 -0.000347 -0.000413 0.000087 -0.000820 0.000805 -0.000487 -0.000383 -0.000023 -0.000718 0.891258 -0.888279 -0.001684 0.897069 -0.896543 Table 17 - 4-MeOMe-1,2,3-Triazole + DME, Energy: -549.42683 N N C C N C O C H C O C H H H H H H H H H H H H 7 7 6 6 7 6 8 6 1 6 8 6 1 1 1 1 1 1 1 1 1 1 1 1 -1.429055 -2.513129 -2.353225 -1.079933 -0.544086 -0.345684 -1.042440 -0.395996 -3.310039 2.948523 2.794781 2.523161 -3.098676 0.692176 -0.317370 -0.976701 0.630667 -0.366387 3.150771 3.796195 2.037363 2.388063 1.614469 3.363555 -2.334785 -1.686233 -0.341364 -0.169356 -1.387436 1.104280 2.126430 3.378770 -2.234331 -0.675802 0.041361 -0.850849 0.353758 1.009627 1.331146 4.105607 3.347288 3.682953 0.064293 -1.372543 -1.233289 -0.238898 -1.432251 -1.540582 125 -0.213231 0.262130 0.267825 -0.238747 -0.522410 -0.480087 0.218988 0.061215 0.567173 -0.997105 0.220960 1.292064 0.620231 -0.133128 -1.558621 0.629767 0.447406 -0.993782 -1.772844 -0.937548 -1.241116 2.185001 1.099155 1.452310 Table 18 - 4-MeOMe-1,2,3-Triazole-(Li+)-DME, Energy: -556.82511 N C C N N H C O C Li O C C H H H H H H H H H H H H 7 6 6 7 7 1 6 8 6 3 8 6 6 1 1 1 1 1 1 1 1 1 1 1 1 -2.539124 -3.019176 -1.876720 -0.801333 -1.199674 -3.059282 -1.682903 -0.270987 0.018535 0.909566 2.623103 3.919960 2.713420 -4.075021 -2.134743 -2.134755 1.102886 -0.396201 -0.396049 3.764095 4.473732 4.474708 1.694002 3.242174 3.241042 -1.949097 -0.684398 0.095925 -0.734624 -2.005040 -2.824051 1.578916 1.827292 3.238513 0.284648 -0.446236 0.170810 -1.884791 -0.455724 2.036726 2.036726 3.334805 3.707122 3.707166 1.248972 -0.123227 -0.124252 -2.269694 -2.223238 -2.222245 126 -0.000040 0.000349 0.000135 -0.000250 -0.000456 -0.000077 0.000047 0.000068 -0.000003 -0.000422 -0.000385 0.000008 0.000483 0.000654 -0.889266 0.889354 -0.000099 -0.896251 0.896291 -0.000711 0.895538 -0.894577 0.000043 -0.894524 0.896534 Table 19 - 4-MeOMe-1,2,3-Triazole + Glyme, Energy: -702.78713 C N N N C C O C H C O C C O C H H H H H H H H H H H H H H H H 6 7 7 7 6 6 8 6 1 6 8 6 6 8 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 -2.478803 -2.675589 -3.984193 -4.589200 -3.703818 -1.120907 -1.300824 -0.052026 -5.602680 5.178466 4.557816 3.146629 2.586424 1.176231 0.534779 -3.984840 -0.549808 -0.548367 -0.267295 0.535852 0.537148 6.254884 4.904722 4.903727 2.790691 2.791692 2.940179 2.939294 -0.537682 0.812900 0.812215 0.196905 -1.148750 -1.397440 -0.190870 0.834167 0.810048 2.218779 2.888165 -0.157436 1.082167 -0.190072 -0.079314 -1.483697 -1.363264 -2.634239 1.875212 0.483306 0.482880 3.957131 2.634824 2.634363 0.909111 1.660143 1.662741 0.463721 0.461177 -2.027253 -2.024740 -2.441753 -3.212544 -3.210216 127 0.000124 0.000155 -0.000791 -0.001408 -0.000883 0.001080 0.000641 0.001377 -0.002181 -0.001527 -0.000020 -0.000972 0.000728 -0.000139 0.001279 -0.001233 0.881383 -0.878110 0.000951 0.893783 -0.890041 -0.000673 -0.894656 0.889610 0.887762 -0.891654 -0.887519 0.890859 0.000655 -0.889785 0.894064 Table 20 - 4-MeOMe-1,2,3-Triazole-(Li+)-Glyme, Energy: -710.21590 N C C N N H C O C Li C C O O C C H H H H H H H H H H H H H H H H 7 6 6 7 7 1 6 8 6 3 6 6 8 8 6 6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 3.299133 3.591498 2.358265 1.416276 1.988611 3.932742 1.955881 0.539626 0.018763 -0.458915 -2.808212 -3.177147 -1.977638 -1.715303 -1.273437 -2.208439 4.596253 2.206739 2.459727 -1.055442 0.218827 0.464224 -3.660560 -2.497670 -3.939135 -3.565006 -0.442063 -2.083851 -0.940878 -1.238828 -2.878488 -2.644500 -1.391946 -0.208090 0.260171 -0.653765 -1.679782 -2.054501 1.489216 1.618758 2.733839 0.035883 -1.373665 -0.098152 0.392572 -1.058415 -2.203077 1.547679 0.182418 1.401335 2.379743 2.744697 2.609596 3.666621 -1.749429 -2.142975 -0.295526 0.647846 -1.867561 -2.568302 -2.996768 1.850570 1.294219 2.357974 128 -0.956158 -0.370007 0.045327 -0.310829 -0.936820 -1.397485 0.793761 0.644349 1.385323 0.005440 0.162244 -0.549501 -1.160896 1.034457 1.783635 -1.979974 -0.300227 1.859884 0.396824 1.208254 2.453753 1.028300 0.741491 -0.556713 -1.313337 0.156383 2.401161 2.420152 1.107638 -2.371514 -2.805819 -1.386545 MP2(full)/cc-pVDZ and MP2(full)/cc-pVDZ(Li-C) Geometries and Energies of Heterocycle Ligands With and Without a Bound Lithium Cation Table 21 - Water, Energy: -76.23099 O H H 8 1 1 0.000000 0.749274 -0.749274 0.121440 -0.485761 -0.485761 Table 22 - Water-Li, Energy: O H H Li 8 1 1 3 0.000031 0.764905 -0.765251 0.000031 0.000000 0.000000 0.000000 -83.56307 -0.336917 -0.933476 -0.932955 1.520589 0.000000 0.000000 0.000000 0.000000 Table 23 - 1H-1,2,3-Triazole, Energy: -241.56224 C C N N N H H H 6 6 7 7 7 1 1 1 1.044324 -0.193485 -1.068095 -0.442347 0.860325 -2.083561 2.037764 -0.508419 0.501034 1.133670 0.091906 -1.103068 -0.851509 0.114839 0.942418 2.173217 -0.000241 -0.000047 0.000259 -0.000554 0.000522 0.000445 -0.000272 -0.000039 Table 24 - 1H-1,2,3-Triazole-(Li+), Energy: -248.91584 C C N N N H Li H H 6 6 7 7 7 1 3 1 1 0.440542 1.352631 0.577164 -0.719560 -0.810911 0.869483 -2.670590 0.616999 2.439403 1.154937 0.102820 -1.012504 -0.714571 0.624864 -1.990796 -0.043960 2.227966 0.063643 129 -0.000143 0.003212 0.000923 -0.005628 -0.004825 0.001092 0.013027 0.000868 0.007266 Table 25 - 2H-1,2,3-Triazole, Energy: -241.57086 N C C N N H H H 7 6 6 7 7 1 1 1 -5.976577 -5.111302 -3.907648 -4.020073 -5.259169 -5.646359 -5.402483 -2.986913 -0.550631 -0.381201 0.144143 0.303132 -0.126571 -0.130723 -0.642304 0.411958 0.130350 1.159728 0.661051 -0.680253 -0.907476 -1.846358 2.174118 1.173376 Table 26 - 2H-1,2,3-Triazole-(Li+), Energy: -248.89669 N C C N N H Li H H 7 6 6 7 7 1 3 1 1 1.199898 1.194157 -0.131225 -0.945933 -0.084359 -0.382425 -2.923887 2.124979 -0.535731 -0.705115 0.647546 1.099654 0.004518 -1.017186 -1.991780 0.071075 1.209522 2.110316 0.000004 0.000047 -0.000038 -0.000018 -0.000028 -0.000011 0.000093 0.000097 -0.000127 Table 27 – Pyrazole, Energy: -225.55411 C C C N N H H H H 6 6 6 7 7 1 1 1 1 0.654429 -0.740447 -1.090029 -0.001328 1.026709 1.971089 1.386806 -1.398705 -2.080583 0.959481 0.955062 -0.415639 -1.216843 -0.352978 -0.721745 1.764111 1.820833 -0.867880 130 -0.000192 0.000069 -0.000031 -0.000180 0.000301 0.000245 -0.000753 0.000690 -0.000105 Table 28 - Pyrazole-(Li+), Energy: -232.89344 C C C N N H Li H H H 6 6 6 7 7 1 3 1 1 1 -1.217051 -1.158148 0.212738 0.963468 0.066118 0.373333 2.914486 -2.053066 -1.994736 0.698675 -0.611604 0.782397 1.085759 -0.052213 -1.054316 -2.022973 -0.000124 -1.308393 1.476575 2.061555 0.000197 0.000080 -0.000036 -0.000100 -0.000320 0.000834 0.000342 -0.000238 0.000309 -0.000436 Table 29 - Pyridizine, Energy: -263.52492 C C N N C C H H H H 6 6 7 7 6 6 1 1 1 1 0.696581 1.326496 0.673061 -0.671684 -1.326431 -0.697895 1.281260 2.417781 -2.417621 -1.283570 1.190468 -0.064773 -1.243688 -1.244414 -0.066219 1.189698 2.114235 -0.151384 -0.154020 2.112838 -0.000002 0.000023 -0.000030 -0.000011 0.000028 -0.000009 -0.000010 0.000076 0.000083 -0.000105 Table 30 - Pyridazine-(Li+), Energy: -270.88587 C C N N C C Li H H H H 6 6 7 7 6 6 3 1 1 1 1 1.382482 0.139661 -1.021672 -1.021853 0.139225 1.382268 -2.890148 2.311177 0.046091 0.045262 2.310773 -0.698373 -1.352618 -0.674691 0.674247 1.352606 0.698777 0.000035 -1.274006 -2.441530 2.441481 1.274705 131 0.000895 -0.000433 -0.001894 -0.001973 -0.000421 0.000941 0.005989 0.002050 -0.000496 -0.000539 0.002194 Table 31 - Pyrimidine, Energy: -263.55995 C C C N C C H H H H 6 6 6 7 6 7 1 1 1 1 -0.624273 -1.359606 -0.627197 0.719664 1.311700 0.722287 -1.123628 -2.452145 -1.128450 2.406827 1.192792 0.001461 -1.191328 -1.210423 -0.001570 1.208875 2.168175 0.002845 -2.165720 -0.002597 0.000048 -0.000036 0.000042 0.000049 -0.000229 0.000044 0.000024 -0.000120 0.000023 0.000472 Table 32 - Pyrimidine-(Li+), Energy: -270.89194 C C C N C N Li H H H H 6 6 6 7 6 7 3 1 1 1 1 -0.421013 0.973287 1.562278 0.829983 -0.495668 -1.174769 -3.159188 -0.950703 1.573161 2.649698 -1.094388 1.190117 1.133241 -0.139436 -1.269276 -1.113893 0.061071 0.046440 2.148084 2.045580 -0.264078 -2.031644 132 -0.000404 0.000080 0.000478 0.000146 -0.000487 -0.000653 0.001982 -0.000676 0.000190 0.001150 -0.001061 Table 33 - 1-Methoxyethyl-1,2,3-Triazole, Energy: -434.13854 N C C N N C C O C H H H H H H H H H 7 6 6 7 7 6 6 8 6 1 1 1 1 1 1 1 1 1 -2.660389 -2.946969 -1.865096 -0.964418 -1.439767 0.392084 1.403030 2.678581 3.700606 -3.899815 -1.670943 0.525358 0.523186 1.257391 1.235656 4.661577 3.643722 3.645302 -1.028133 0.220350 1.061496 0.250844 -1.007626 0.541698 -0.099487 0.262705 -0.323394 0.448900 2.113062 1.632683 0.150360 -1.197239 0.266025 -0.005079 -1.428308 0.008371 -0.078747 -0.546344 -0.304891 0.318990 0.449009 0.754764 -0.186760 0.288964 -0.493869 -1.018944 -0.500751 0.771686 1.773181 -0.187071 -1.221524 -0.068069 -0.473810 -1.548570 Table 34 - 1-Methoxyethyl-1,2,3-Triazole-(Li+), Energy: -441.52051 N C C N N C C O C Li H H H H H H H H H 7 6 6 7 7 6 6 8 6 3 1 1 1 1 1 1 1 1 1 -2.057818 -2.866208 -2.162886 -0.926551 -0.877527 0.243421 1.487218 1.973659 3.329910 0.799762 -3.894759 -2.428250 -0.007664 0.425982 2.266529 1.284353 3.630291 3.997577 3.381930 -1.335981 -0.301990 0.896430 0.516189 -0.820097 1.323340 0.940146 -0.354630 -0.554034 -1.791957 -0.466432 1.937013 2.369653 1.237932 1.690722 0.943852 -1.567554 0.179810 -0.456208 133 0.013517 0.366757 0.251910 -0.174355 -0.321138 -0.518017 0.268827 -0.128106 0.329461 -0.573712 0.680158 0.424134 -0.292033 -1.600883 0.050081 1.354829 0.032150 -0.147675 1.425441 Table 35 - 4-Methoxymethyl-1,2,3-Triazole, Energy: -394.95807 H C C N N H C O C H H H H H H 7 6 6 7 7 1 6 8 6 1 1 1 1 1 1 -1.405969 -0.368718 -0.871700 -2.217947 -2.549332 -2.959968 1.063089 1.858254 3.234027 -0.398628 1.271713 1.270209 3.791413 3.515183 3.516596 -1.162912 -0.277303 1.018914 0.822034 -0.484718 1.515442 -0.706968 0.461184 0.139878 1.995599 -1.324555 -1.340610 1.086312 -0.436320 -0.453294 -0.002175 0.002012 0.002962 0.000423 -0.003212 -0.000579 0.005110 -0.005453 -0.001272 0.005670 0.902202 -0.880984 -0.009800 0.901277 -0.892292 Table 36 - 4-Methoxymethyl-1,2,3-Triazole-(Li+), Energy: -402.34226 N C C N N C C O C Li H H H H H H 7 6 6 7 7 1 6 8 6 3 1 1 1 1 1 1 0.749594 0.436171 1.631230 2.578102 2.070335 3.592543 -0.998122 -1.815983 -3.217923 -0.889380 1.870559 -1.225006 -1.225061 -3.778754 -3.466332 -3.466300 0.893723 -0.436000 -1.150827 -0.177254 1.059228 -0.285424 -0.877404 0.302844 -0.034976 1.974875 -2.211297 -1.484285 -1.478373 0.907854 -0.618427 -0.612070 134 0.001300 0.000579 -0.000871 -0.000871 0.000317 -0.001846 0.001926 -0.001866 -0.000558 0.000007 -0.001787 -0.892289 0.900141 -0.003961 -0.900680 0.903671 MP2(full)/6-31G(d) Geometries and Energies of SN2 Transition States in Cartesian Coordinates‡ Table 37 - Methyl Mesylate, Cs, Energy: -758.53145 S O C C H N H H H H H H H H O O 16.0 8.0 6.0 6.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 8.0 8.0 1.15939 0.34332 -1.56443 2.83434 3.49926 -3.39174 -1.77836 -3.42903 -3.88908 -3.88908 -1.34932 -1.34932 2.99358 2.99358 0.95553 0.95553 -0.45877 0.83946 0.25102 0.13571 -0.72871 -0.29315 1.30659 -1.31310 0.03958 0.03958 -0.24862 -0.24862 0.73491 0.73491 -1.21641 -1.21641 ‡ 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.82614 0.82614 -0.92968 0.92968 -0.89588 0.89588 -1.25308 1.25308 This appendix is a republication of data from the supporting information of Spahlinger, G.; Jackson J. E. Phys. Chem. Chem. Phys. 2014, 16, 24559 – 24569. It has been republished with permission from the PCCP Owner Societies. The original article may be found online at the following link: http://pubs.rsc.org/en/content/articlelanding/2014/cp/c4cp03741c#!divAbstract 135 Table 38 - Dimethylsulfate, C1, Energy: -833.56441 C O S O C O O N H H H H H H H H H 6.0 8.0 16.0 8.0 6.0 8.0 8.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -3.23105 -2.38762 -1.09812 -0.48480 0.29671 -0.26375 -1.64534 1.08021 -4.02379 -3.65542 -2.66470 -0.70677 0.81085 0.70385 0.74849 2.09771 0.83764 0.53029 1.60405 1.06888 2.41333 3.22502 0.29334 0.37490 4.04056 1.00238 -0.00086 -0.16271 3.34643 2.29328 3.95738 4.99383 4.06770 3.49160 0.56815 0.11677 -0.78967 -1.11775 0.48992 0.14471 -1.94913 2.04906 1.14786 -0.28628 1.19552 0.86179 0.65588 -0.18691 2.19684 1.98137 2.87422 Table 39 - Methyl Triflate, C1, Energy: -1055.61053 S O O O C C F F F N H H H H H H 16.0 8.0 8.0 8.0 6.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 2.35501 2.11595 2.82997 3.09460 3.00518 0.69775 0.20757 -0.15989 0.74865 2.95037 2.06759 3.01260 3.92737 3.77193 2.12777 2.90357 0.45850 1.89145 0.01740 -0.19380 0.78181 -0.29530 -0.03145 0.20358 -1.62525 1.74648 0.29666 1.70453 0.28607 2.34060 2.34956 1.12215 136 0.38755 0.14978 1.69291 -0.77547 -2.45037 0.20277 -1.03440 1.10085 0.34790 -4.15797 -2.65665 -1.89490 -2.70168 -4.26976 -4.18146 -4.96329 Table 40 - Methylfluorosulfonate, C1, Energy: -818.40115 S O O O C F N H H H H H H 16.0 8.0 8.0 8.0 6.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.45745 -0.73479 -0.66826 0.82628 1.03360 -1.54639 1.26902 0.19039 0.87039 2.01551 2.04944 0.42573 1.43614 -0.38751 1.03262 -0.99018 -0.82380 0.02595 -1.11887 0.86801 -0.54494 0.97787 -0.41591 1.52487 1.39054 0.18837 1.66574 1.46126 2.96502 0.99410 -0.74241 0.67800 -2.48653 -1.09193 -0.26719 -0.75708 -2.48154 -2.72549 -3.22871 Table 41 - Methyl TFSI (anti) C1, Energy: C N S S O O O O C F F F C F F F N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 9.0 9.0 9.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.66116 0.76965 2.28825 0.29060 1.13996 -1.16191 2.38041 3.32762 0.53203 0.13186 1.81216 -0.21007 2.19505 3.34478 1.95190 1.19723 -2.06015 0.12249 -0.94777 -1.08444 -1.93545 -2.05019 -2.98197 -0.61732 0.64248 0.07028 2.15820 2.84436 2.08861 -1.12693 1.08767 3.01854 4.28929 2.98432 2.41267 -0.58939 -1.19444 0.38496 -1.49320 -1.84880 -1.32101 0.12036 -0.56937 -2.09763 -2.71145 -1.42349 137 -1919.67259 0.85893 0.24164 0.04048 -0.14497 -1.10654 -0.30589 0.87802 0.03777 1.46019 1.35324 1.83089 2.40979 -1.67185 -1.98500 -2.54919 -1.74320 1.46472 1.08911 1.58802 -0.12863 2.44612 0.92037 1.36270 Table 42 - Methyl TFSI (gauche) C1, Energy: -1919.67076 C N S S O O O O C F F F C F F F N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 9.0 9.0 9.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -3.87907 -2.46911 -1.05071 -3.05201 -2.15451 -4.46939 -1.05368 -0.71369 -3.07161 -3.58459 -1.84005 -3.84154 0.21236 0.29884 1.39677 -0.10592 -5.28215 -3.12177 -4.03898 -4.42346 -5.07590 -5.36234 -6.19044 -1.83954 -0.66098 -1.37594 0.69649 1.31547 0.47677 -2.66542 -1.28112 1.81762 2.99752 2.00090 1.29557 -0.37542 0.84929 -0.98774 -0.27843 -3.00105 -2.59309 -1.09180 -1.76888 -3.24306 -3.87042 -2.53716 0.39261 -0.40728 -0.82492 -1.12157 -2.08550 -1.41406 -0.12975 -2.23727 0.33687 -0.02300 0.81939 1.31448 0.06172 -0.46056 -0.05052 1.35979 1.17290 0.53190 1.14924 -0.53294 2.14198 0.64556 1.15092 Table 43 - Methyl FSI, C1, Energy: -1445.25353 C N S S O O O O F F N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.16332 0.23789 1.79197 -0.16317 0.69968 -1.61089 2.69028 1.76682 0.15377 2.16658 -2.55462 -0.50627 -1.07967 -1.83034 -2.20974 -2.86906 -3.36668 -0.57013 0.55663 0.08379 2.09227 2.72452 2.11438 1.07449 -1.28644 2.82452 -0.02105 -1.69089 -1.41217 0.02351 -0.24811 -2.15762 -2.41160 -1.13160 138 0.76693 -0.09700 -0.02432 -0.43270 -1.40357 -0.53546 0.52532 0.45671 0.97651 -1.58660 1.58284 0.62750 1.66179 -0.01361 2.42195 0.93291 1.84525 Table 44 - Methyl MSI (anti) C1, Energy: -1325.52993 C N S S O O O O C H H H C H H H N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.90188 0.57282 2.13085 0.15441 1.05762 -1.29032 2.83856 2.04988 0.36046 0.07588 1.40447 -0.29198 2.92255 3.96082 2.85635 2.40695 -2.27604 -0.22703 -0.78324 -1.51230 -1.93884 -2.59571 -3.08017 -0.77026 0.37880 0.04956 1.72961 1.97950 1.58083 1.23403 -1.15505 3.08876 4.00057 3.11933 2.92828 -0.41104 -0.65469 0.43160 -1.28081 -1.85552 -1.59409 -0.19108 -0.38219 -2.36085 -2.54128 -1.29313 139 1.01037 0.16851 0.55812 -0.65742 -1.79024 -0.90549 1.06923 1.40218 0.47314 -0.05455 0.78265 1.33173 -0.96597 -0.73449 -1.65300 -1.37289 1.74458 0.85233 1.91016 0.21102 2.56473 1.06005 2.02451 Table 45 - Methyl MSI (gauche) C1, Energy: -1325.52302 C N S S O O O O C H H H C H H H N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.06997 0.47826 0.77880 0.18542 0.20869 -0.97466 1.17581 -0.33913 1.60757 1.47421 2.50235 1.66760 2.19991 1.94467 2.43613 3.02871 -2.50727 -0.35207 -1.13760 -1.60266 -2.29563 -2.68341 -3.36317 -1.06292 0.13425 -0.46294 1.73729 2.53612 1.83955 -1.86008 -0.21158 2.22517 3.27192 2.10811 1.59679 0.40893 1.46254 -0.02782 0.25597 -2.19857 -1.86516 -0.39700 -0.80954 -2.63776 -2.93659 -1.65415 0.37339 -0.29456 -1.81098 -0.04374 -1.27794 0.85874 -1.57131 -2.73173 0.91248 1.19195 0.30094 1.80065 -2.42786 -2.53264 -3.39992 -1.73627 0.98395 0.35027 1.21640 -0.52860 1.87953 0.30200 1.09124 Table 46 - Methyl MSA, C1, Energy: -738.64549 C N S O O C N H H H H H H H H H H 6.0 7.0 16.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.30251 0.19773 0.23801 1.34285 -1.14025 0.55593 -2.61886 -0.49270 -1.38337 -1.70728 -2.45959 -2.69837 -3.51020 1.15436 0.52943 1.54139 -0.21478 -0.66876 0.67481 0.45781 -0.41401 0.10748 2.05136 -1.74138 -1.37337 0.11501 -0.49913 -2.07242 -2.55369 -1.24395 0.56209 1.93270 2.40051 2.74994 140 0.30504 -0.52460 -2.10706 -2.56768 -2.54485 -2.85423 0.91736 0.40479 1.04049 -0.68266 1.87005 0.30348 0.89449 -0.17789 -3.93872 -2.54249 -2.52914 Table 47 - Methyl FSA, C1, Energy: -798.52240 C N S O O F N H H H H H H H Table 48 C N S O O F N H H H H H H C H C C H H H H H H 6.0 7.0 16.0 8.0 8.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.19943 0.43162 -0.17642 0.77442 -1.32783 -0.91823 -2.69158 -0.47177 -1.35170 -1.50666 -2.68325 -2.78539 -3.51620 1.27082 -0.77697 0.08935 1.20365 2.08201 0.65982 2.23710 -1.51433 -1.42425 0.21199 -0.97550 -1.42893 -2.50283 -1.02590 0.45106 0.16278 -0.87921 -1.80374 -2.47123 -2.52223 -0.71203 0.94819 0.62582 0.56129 -0.85018 1.96554 0.71073 0.59484 -0.42114 MeiprFSA, C1, Energy: -916.03637 6.0 7.0 16.0 8.0 8.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 6.0 1.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.55910 1.14889 0.58564 1.54941 -0.56224 -0.17324 -2.05491 0.16204 -0.71244 -0.82453 -2.05987 -2.15684 -2.86788 2.39504 2.42687 2.41952 3.61997 3.32047 1.54541 2.42414 4.53926 3.64292 3.58153 -0.57798 0.04259 0.93809 1.65973 0.27135 2.19275 -1.12119 -1.09370 0.47792 -0.99309 -0.83085 -2.13687 -0.70673 0.42408 -0.24845 1.85866 0.11669 2.02241 2.06661 2.57046 0.26129 0.77279 -0.91958 141 0.51173 -0.61079 -1.76348 -2.59026 -2.38087 -0.93185 1.38979 1.12841 0.66585 -0.44652 2.36895 1.35578 0.93005 0.07307 0.94370 0.59948 -0.78361 1.19983 1.22214 -0.22883 -0.20546 -1.65555 -1.13011 Table 49 - Methyl Acetate, Cs, Energy: C C O O C N H H H H H H H H H 6.0 6.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 2.71505 1.21986 0.83498 0.46339 -1.52119 -3.22174 3.29119 -1.01488 -3.90645 -3.38394 -3.38394 -1.55695 -1.55695 2.96968 2.96968 -0.28053 0.01855 1.21455 -1.02504 -0.37468 0.20938 0.64546 0.58559 -0.54807 0.78874 0.78874 -0.93747 -0.93747 -0.87697 -0.87697 -323.88097 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.82474 0.82474 -0.91937 0.91937 -0.88004 0.88004 Table 50 - Methyl Trifluoroacetate, Cs, Energy: -620.97437 C C O O C N H H H H H H F F F 6.0 6.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 9.0 9.0 9.0 -2.74774 -1.25478 -0.94712 -0.50185 1.43691 3.21694 1.02108 3.86299 3.41129 3.41129 1.48885 1.48885 -3.55230 -3.05977 -3.05977 0.29836 -0.07407 -1.27898 0.96265 0.36815 -0.16221 -0.62941 0.62802 -0.73166 -0.73166 0.91979 0.91979 -0.77981 1.03794 1.03794 142 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.82442 0.82442 -0.92412 0.92412 0.00000 -1.09021 1.09021 Table 51 - Methyl Cyanoformate, Cs, Energy: -376.72778 C C O O C N H H H H H H N 6.0 6.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 7.0 -2.69698 -1.24349 -0.93291 -0.49173 1.44202 3.24599 1.05365 3.87723 3.45214 3.45214 1.49444 1.49444 -3.85118 0.22415 -0.11266 -1.31631 0.92582 0.35379 -0.14958 -0.65397 0.65248 -0.71505 -0.71505 0.90351 0.90351 0.47500 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.82425 0.82425 -0.92510 0.92510 0.00000 Table 52 - Dimethylcarbonate, Cs, Energy: -398.92298 O C O O C N C H H H H H H H H H 8.0 6.0 8.0 8.0 6.0 7.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 2.03073 0.64754 0.14739 0.04691 -1.96009 -3.75966 2.59536 3.67574 -1.62111 -4.34362 -3.99559 -3.99559 -1.95109 -1.95109 2.29741 2.29741 0.31305 0.36460 1.50177 -0.77312 -0.40610 -0.03986 -0.99593 -0.84328 0.62333 -0.87706 0.51406 0.51406 -0.96455 -0.96455 -1.56072 -1.56072 143 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.82420 0.82420 -0.92205 0.92205 -0.88658 0.88658 Table 53 - Dimethylurethane, Cs, Energy: -379.04927 O C O N C N C H H H H H H H H H H 8.0 6.0 8.0 7.0 6.0 7.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 2.02579 0.66684 0.34646 -0.15741 -2.18990 -3.75189 2.90179 3.91019 -1.53527 -4.55234 0.35677 -3.81515 -3.81515 -2.29337 -2.29337 2.75358 2.75358 0.47650 0.13493 -1.07929 1.16869 0.36842 -0.46730 -0.64678 -0.22906 -0.49858 0.16691 2.04827 -1.06606 -1.06606 0.92365 0.92365 -1.26953 -1.26953 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.82479 0.82479 -0.91858 0.91858 -0.88536 0.88536 Table 54 - Methyl Acetamide, Cs, Energy: -304.00329 N O C C H H H C H H H N H H H H 7.0 8.0 6.0 6.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 1.0 0.36989 0.56626 1.08414 2.61143 0.95893 2.98632 2.98632 -1.74849 -1.16436 -1.79635 -1.79635 -3.38196 -4.12634 -3.49362 -3.49362 3.00807 0.72035 -1.56104 -0.40181 -0.34590 1.55229 -0.87554 -0.87554 0.13165 -0.79005 0.69735 0.69735 -0.55392 0.14517 -1.14575 -1.14575 0.67358 144 0.00000 0.00000 0.00000 0.00000 0.00000 0.87987 -0.87987 0.00000 0.00000 -0.91752 0.91752 0.00000 0.00000 -0.82443 0.82443 0.00000 Table 55 - Methyl Trifluoroacetamide, Cs, Energy: -601.10242 C C O N C N F H H H F F H H H H 6.0 6.0 8.0 7.0 6.0 7.0 9.0 1.0 1.0 1.0 9.0 9.0 1.0 1.0 1.0 1.0 2.11981 0.58992 -0.01703 0.04913 -2.09064 -3.85725 2.76033 -1.71854 -4.45550 0.74265 2.55559 2.55559 -2.06198 -2.06198 -4.08151 -4.08151 -0.52278 -0.40223 -1.50505 0.80354 0.55890 0.17215 0.68086 -0.46030 0.99955 1.54876 -1.19283 -1.19283 1.11772 1.11772 -0.38651 -0.38651 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -1.08864 1.08864 -0.92160 0.92160 -0.82460 0.82460 Table 56 - Methylcyanoformamide, Cs, Energy: -356.85536 C C O N N H C H N H H H H H 6.0 6.0 8.0 7.0 7.0 1.0 6.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 -2.13211 -0.65322 -0.22872 0.08105 -3.30421 -0.47753 2.15409 1.64901 3.85744 4.56232 2.20896 2.20896 4.00477 4.00477 0.05823 -0.13475 -1.31677 0.96986 0.21366 1.82290 0.41429 -0.54449 -0.21663 0.52203 0.96893 0.96893 -0.80038 -0.80038 145 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.92261 0.92261 -0.82462 0.82462 Table 57 - Methyl Succinimide, Cs, Energy: -455.08510 N O O C C C C H H H H C H H H N H H H 7.0 8.0 8.0 6.0 6.0 6.0 6.0 1.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 0.05261 2.33705 -2.23756 1.17102 -1.08350 0.76545 -0.75813 1.19813 1.19813 -1.21286 -1.21286 -0.35264 -1.34340 0.21388 0.21388 -0.80868 0.00960 -1.36974 -1.36974 1.01151 0.61253 0.72233 0.21489 0.26114 -1.26900 -1.23665 -1.75517 -1.75517 -1.70250 -1.70250 3.13048 2.69223 3.11421 3.11421 4.85024 5.46176 5.06521 5.06521 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.87941 -0.87941 0.87953 -0.87953 0.00000 0.00000 -0.91761 0.91761 0.00000 0.00000 -0.82586 0.82586 Table 58 - 1,3-Propanesultone, C1, Energy: -796.52517 C C C O S O O N H H H H H H H H H 6.0 6.0 6.0 8.0 16.0 8.0 8.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -3.45351 -2.19091 -1.79074 -3.45727 -4.49739 -5.67323 -4.70828 -0.11650 -3.94260 -3.25237 -1.36522 -2.37547 -2.14297 -1.32008 -0.27813 0.32686 0.54204 0.75616 0.52215 -0.94950 -1.71120 -0.65306 -0.63998 -0.59716 -0.67549 1.69560 0.73939 1.11095 0.85603 -1.57827 -1.42299 -0.23260 -1.58056 -0.09379 146 0.30115 -0.52144 -0.57062 0.31553 -0.06605 0.80762 -1.52723 -1.48034 0.03500 1.37412 -0.10902 -1.54511 -1.37184 0.27731 -2.38518 -1.64854 -0.96046 Table 59 - N-Triflylpropanesultam, C1, Energy: -1660.59152 C C C N S O O S O O C F F F N H H H H H H H H H 6.0 6.0 6.0 7.0 16.0 8.0 8.0 16.0 8.0 8.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -6.80903 -6.26053 -5.04418 -4.41467 -5.48929 -5.20853 -5.78052 -3.17308 -3.27811 -2.80960 -1.83920 -2.15599 -0.68200 -1.67732 -5.31761 -7.12190 -7.64294 -7.06380 -5.98698 -4.08081 -5.05721 -5.41267 -4.49815 -6.13924 0.62350 1.05260 0.24503 0.07993 0.79614 2.23361 0.01902 -0.88152 -1.65929 -1.51850 0.33782 1.10961 -0.28928 1.12280 0.27377 -0.42435 1.25823 0.95190 2.11063 0.71275 -0.83451 1.22307 -0.15270 -0.25975 0.94358 2.30011 2.73049 0.77498 -0.25481 -0.36327 -1.45839 0.43702 -0.79036 1.70950 0.12987 -0.91644 -0.11858 1.21270 4.63129 0.93553 0.63005 3.03707 2.24992 2.84873 2.70811 4.99570 5.06855 4.92010 Table 60 - Methyl Chloride, C3v, Energy: -555.66764 C H H H H H H Cl N 6.0 1.0 1.0 1.0 1.0 1.0 1.0 17.0 7.0 0.00000 -0.53245 -0.53245 1.06490 0.47750 0.47750 -0.95501 0.00000 0.00000 0.00000 0.92223 -0.92223 0.00000 -0.82706 0.82706 0.00000 0.00000 0.00000 147 0.98077 1.13760 1.13760 1.13760 -1.18908 -1.18908 -1.18908 3.41809 -0.82697 MP2(full)/6-31G(d) Geometries and Energies of van der Waals complexes Table 61 - Methyl Mesylate, C1, Energy: -758.58709 S O O O C C H H H N H H H H H H 16.0 8.0 8.0 8.0 6.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 2.07553 1.98721 3.03576 2.26572 3.21452 0.47676 -0.23040 0.20090 0.54040 5.32093 3.39137 2.75180 4.13737 4.61506 6.21396 5.09539 0.51573 1.90663 0.15510 -0.44335 0.05729 -0.07754 0.14685 0.44264 -1.15053 1.83568 -0.79804 0.87475 0.39319 2.56859 2.29069 1.28412 0.18915 -0.25416 1.23078 -1.10417 -2.09851 0.65915 -0.13785 1.57712 0.83612 -0.17260 -2.74665 -2.65164 -1.62272 -0.20399 0.00351 0.65259 Table 62 - Dimethylsulfate, C1, Energy: -833.61240 C O S O C O O N H H H H H H H H H 6.0 8.0 16.0 8.0 6.0 8.0 8.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.53204 0.10826 1.70441 1.84848 3.02227 2.37762 1.96618 5.05312 -1.57531 -0.42705 -0.10311 2.96440 2.92959 3.92979 5.98747 4.39412 4.96133 -2.61811 -1.31517 -1.38677 0.16909 0.82869 -1.72019 -2.18795 -1.66836 -2.40567 -3.08419 -3.25026 1.83652 0.83798 0.31584 -1.86208 -2.11560 -2.16274 148 0.15498 0.15639 -0.06897 -0.38204 0.19709 1.17815 -1.25647 -0.70869 0.37460 -0.82454 0.93483 -0.20682 1.28227 -0.12212 -1.06196 -1.34245 0.17586 Table 63 - Methyl Triflate, C1, Energy: -1055.65367 S O O O C C F F F N H H H H H H 16.0 8.0 8.0 8.0 6.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 2.20717 2.02832 2.91878 2.70847 3.12432 0.53321 -0.13890 -0.11248 0.61466 5.24527 3.34404 2.30471 4.00749 4.84718 6.24956 5.10327 0.60708 1.94149 0.36265 -0.42245 0.14170 -0.10498 -0.02905 0.60054 -1.37976 1.74614 -0.73845 0.71340 0.75565 2.67830 1.86479 1.29429 0.29261 -0.25910 1.53519 -0.82763 -2.11433 0.51115 -0.64295 1.44453 0.89367 -0.13154 -2.71390 -2.54797 -1.95000 -0.04216 -0.24715 0.76956 Table 64 - Methylfluorosulfonate, C1, Energy: -818.44356 S O O O C F N H H H H H H 16.0 8.0 8.0 8.0 6.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.61956 -0.84288 0.00645 0.00621 0.23617 -2.06612 2.33568 0.60254 -0.69879 0.98718 2.06008 3.33331 2.22440 -0.01031 1.30202 -0.23924 -1.00722 -0.47692 -0.69736 1.16672 -1.33970 -0.11534 0.30629 2.14084 1.16487 0.74401 149 0.67213 0.11379 1.95035 -0.38821 -1.73065 0.77082 0.26904 -2.28119 -2.15655 -1.66285 0.37115 0.06705 1.18854 Table 65 - Methyl TFSI (anti) C1, Energy: -1919.72254 C N S S O O O C C F F F O N H H H H H H F F F 6.0 7.0 16.0 16.0 8.0 8.0 8.0 6.0 6.0 9.0 9.0 9.0 8.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 9.0 9.0 9.0 -0.26467 0.41561 1.61248 0.09380 1.22812 -0.55561 1.30838 3.08627 -1.22869 -1.63951 -0.76557 -2.25420 1.85204 -3.27319 0.28315 -0.28348 -1.28730 -4.03026 -3.70618 -2.73259 4.12992 3.34498 2.84185 -1.53625 -0.23126 -0.12976 1.03733 1.93340 0.44608 -1.15564 -0.74737 1.92895 2.95437 2.37600 1.09721 1.25943 -1.16026 -2.11954 -2.05745 -1.36089 -0.57455 -1.89622 -0.58672 -0.75323 0.02963 -1.99517 150 0.16484 0.39525 1.59217 -0.67679 -0.76902 -1.83700 2.57483 0.67435 0.24505 -0.50540 1.40824 0.46151 1.92381 -1.31664 -0.57529 1.11970 -0.17266 -0.97246 -1.87023 -1.96009 1.50371 -0.37464 0.25241 Table 66 - Methyl TFSI (gauche) C1, Energy: -1919.71949 C N S S O O O O C F F F C F F F N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 9.0 9.0 9.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -3.63764 -2.65002 -1.01329 -3.14598 -1.99525 -4.11198 -1.01995 -0.14290 -4.12482 -4.57789 -3.35292 -5.15961 -0.70179 -0.66844 0.47355 -1.66904 -6.71368 -3.31138 -3.70482 -4.61261 -7.42086 -7.21403 -6.27433 -2.16135 -1.06318 -1.43548 0.36419 1.22201 0.05443 -2.83780 -0.87986 1.12717 2.30616 1.30963 0.34697 -0.50135 0.80872 -0.90339 -0.78079 -1.52231 -3.04362 -2.38431 -1.84472 -0.98022 -2.22207 -0.89124 -0.08845 -0.28779 0.01436 -1.03111 -1.23136 -2.07359 0.39523 -1.00114 0.33468 -0.09650 1.40760 0.66462 1.57348 1.34499 2.06028 2.45442 -1.28563 -0.63577 0.97618 -0.46398 -0.79443 -1.82937 -1.95199 Table 67 - Methyl FSI, C1, Energy: -1445.30276 C N S S O O O O F F N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.83597 0.26057 1.77316 -0.00032 -1.25556 1.22415 2.37410 1.65240 -0.28041 2.55228 -3.11589 -0.53618 -0.97342 -1.73650 -3.37293 -3.98272 -2.63218 -0.92101 -0.15853 -0.83171 1.44807 1.82126 2.19124 -0.25542 -2.24543 1.33325 -0.22244 -0.02290 -1.96603 -0.57081 -0.78848 0.85147 -0.47669 0.23513 151 0.68570 0.03331 -0.20120 -0.33436 0.26870 -0.19725 -1.37424 0.05041 -1.91105 1.05854 -1.56959 0.68167 1.70872 0.08395 -1.11727 -1.84960 -2.42662 Table 68 - Methyl MSI (anti) C1, Energy: -1325.59716 C N S S O O O C C H H H O N H H H H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 6.0 6.0 1.0 1.0 1.0 8.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.91580 0.32220 1.12420 0.56593 1.98593 -0.04744 0.47362 2.75641 -0.38261 -0.20706 -0.02182 -1.43657 1.20009 -3.14985 -0.88738 -0.92754 -1.80401 -3.60934 -3.80087 -2.34570 3.33313 3.17675 2.68232 -0.53634 0.17719 1.14196 0.49089 0.79365 -0.64106 0.83134 0.45260 1.94798 2.19102 2.74552 1.71298 2.51767 0.06708 -1.52821 -0.61816 0.00133 0.41138 -0.58630 -0.47849 1.02151 0.55340 -0.59300 152 1.16462 0.78978 1.95545 -0.86013 -1.01966 -1.55674 3.22596 1.96505 -1.20549 -2.25567 -0.55717 -1.04079 1.46588 -1.46265 0.71574 2.24960 0.82537 -2.30310 -1.03252 -1.76958 2.69684 0.96585 2.26269 Table 69 - Methyl MSI (gauche) C1, Energy: -1325.59135 C N S S O O O O C H H H C H H H N H H H H H H 6.0 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.60345 0.45232 2.05582 0.15176 1.39961 -0.53097 1.90420 2.60600 -1.00596 -1.17828 -0.55225 -1.93882 2.94960 2.95473 3.96169 2.47171 -3.50273 -0.53690 -0.48537 -1.57386 -4.22919 -3.92916 -2.79154 -1.08454 -0.14910 -0.74612 0.54769 1.18592 -0.41034 -1.46530 -1.41060 1.81703 2.39382 2.44536 1.35809 0.75260 1.35276 0.44675 1.27101 -0.38157 -2.05073 -1.21652 -0.63630 0.10278 -1.23895 -0.66136 0.59308 0.13373 0.44523 -1.39986 -1.81604 -2.27242 1.70841 -0.73122 -0.95342 -1.86507 -0.18812 -0.62107 0.75408 -0.15314 1.02623 1.58440 -1.16961 0.08625 1.66603 0.37982 -1.69334 -0.82392 -1.84439 Table 70 - Methyl MSA, C1, Energy: -738.74012 C N H S O O C N H H H H H H H H H 6.0 7.0 1.0 16.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.29660 1.38978 2.29714 1.11500 -0.12475 2.37835 0.78513 -2.38816 0.65278 -0.52779 -0.06246 -1.97799 -3.01130 -2.98534 0.64067 -0.12628 1.64863 -0.96040 -0.08339 -0.52363 1.08464 1.76307 1.80203 0.24371 -0.21797 -1.55062 -0.33386 -1.63047 0.62904 -0.59756 0.07760 1.01518 -0.34828 -0.36906 153 1.56476 1.14796 1.01630 0.00513 0.39542 -0.14314 -1.53005 -0.59323 2.41035 1.90183 0.77631 -0.20067 0.11641 -1.36256 -2.28888 -1.42339 -1.79255 Table 71 - Methyl FSA, C1, Energy: -798.60455 C N H S O O F N H H H H H H 6.0 7.0 1.0 16.0 8.0 8.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 0.26599 1.39201 2.17771 1.07843 -0.04715 2.32591 0.50063 -2.33177 0.69834 -0.23563 -0.45537 -2.09204 -3.34480 -2.08991 -1.01034 -0.27619 -0.83197 0.95996 1.70599 1.54862 0.21460 -0.49680 -1.84642 -0.34657 -1.36198 0.43502 -0.57652 -0.50797 1.21145 0.60706 0.27763 -0.39351 0.12390 -0.81861 -1.72081 -0.91025 1.76055 1.91401 0.47071 -0.57764 -0.85746 -1.89789 Table 72 - MeiprFSA, C1, Energy: -916.11962 C N C S O O F N H H H H H H C H C H H H H H H 6.0 7.0 6.0 16.0 8.0 8.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 6.0 1.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.14543 0.86069 2.25515 0.62201 -0.75302 1.74177 0.72827 -3.39035 0.10402 -0.15009 -1.14042 -2.81037 -4.06842 -3.91890 3.04897 2.08369 2.98864 3.91018 2.36910 3.24651 3.99002 3.28536 2.49994 -1.18621 -0.15360 -0.48284 0.65794 1.10258 1.53234 -0.52536 -0.39663 -2.13828 -1.31550 -0.86810 0.30312 0.10977 -0.86316 -1.24595 -1.15343 0.74177 0.42043 1.26838 1.42885 -1.59078 -0.60357 -2.11917 154 0.75151 0.43946 0.85894 -0.94614 -1.03469 -1.21453 -2.06457 -0.20120 0.27073 1.83470 0.43931 -0.65932 0.36340 -0.93464 -0.19605 1.70724 1.38628 1.88086 2.11572 0.58146 0.24163 -1.04622 -0.55669 Table 73 - Methyl Acetate, C1, Energy: -323.95778 C C O O C N H H H H H H H H H 6.0 6.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -4.76330 -3.48640 -2.68648 -3.30869 -2.09098 -6.29875 -4.88517 -4.72516 -5.60502 -2.08778 -1.22546 -2.08180 -6.74213 -6.36621 -5.31062 -0.87502 -0.13526 -0.36043 0.86734 1.61402 2.16070 -1.65388 -1.32253 -0.17832 2.35558 0.95574 2.09519 2.36174 3.01098 2.00614 0.56099 0.29454 -0.59484 1.20657 1.02202 1.18625 -0.19018 1.55723 0.53898 1.81839 1.10386 0.04315 2.07912 0.63224 1.37478 Table 74 - Methyl Trifluoroacetate, C1, Energy: -621.03443 C C O O F F F C H H H N H H H 6.0 6.0 8.0 8.0 9.0 9.0 9.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 -1.75678 -0.37804 0.54553 -0.20424 -1.91152 -2.72629 -1.89017 1.91810 2.47950 2.21883 1.99973 1.48996 1.39698 1.46455 0.64837 -0.01532 0.65146 -0.29094 1.84151 -0.71456 0.89983 -0.87075 0.17812 -0.68333 0.49004 1.01833 -2.76366 -2.95790 -3.66566 -2.26680 155 0.44186 0.42408 0.23608 0.58277 1.58235 0.36481 -0.59275 0.20045 -0.14917 1.20088 -0.48857 -1.32055 -2.31484 -0.85089 -1.03817 Table 75 - Methyl Cyanoformate, Cs, Energy: -376.78433 C C O O N C H N H H H H H 6.0 6.0 8.0 8.0 7.0 6.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 -1.47301 -0.73161 0.57986 -1.27341 -2.11971 1.42222 2.43222 3.46108 2.47835 1.21412 1.21412 3.88029 3.88029 -0.77120 0.49697 0.24591 1.58460 -1.75893 1.43332 1.03286 -1.18080 -1.44492 2.02517 2.02517 -1.62369 -1.62369 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.89140 0.89140 -0.81425 0.81425 Table 76 - Dimethylcarbonate, C1, Energy: -398.99274 O C O O C C H H H H H H N H H H 8.0 6.0 8.0 8.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 -1.71595 -0.66748 0.32101 -0.86388 -2.84908 0.23999 -3.54950 -0.08140 -3.29192 -2.56146 0.39780 1.14739 3.05507 3.27864 2.33736 3.88902 -1.64567 -0.81514 -1.11461 0.34335 -1.20995 1.27555 -2.04128 2.14169 -0.31311 -1.01547 1.54388 0.83630 -0.71645 -1.51546 -1.02664 -0.52819 156 -0.34681 -0.46796 -1.10910 0.18726 0.42601 0.08546 0.37647 0.65991 -0.00759 1.45935 -0.95969 0.49912 0.47509 1.06409 -0.17824 -0.07662 Table 77 - Dimethylurethane, C1, Energy: -379.16693 O C N O H C C H H H H H H N H H H 8.0 6.0 7.0 8.0 1.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 0.04191 -0.00425 -1.10517 1.10629 -0.99067 2.31080 -2.37522 -3.16768 -2.43288 -2.52691 3.09582 2.23378 2.51772 -0.20802 -0.07207 0.67082 -0.36983 1.63211 0.43002 -0.29066 -0.38819 -1.27314 0.31506 0.38138 -0.36787 0.92663 1.09372 -0.43990 0.76334 1.09990 -3.07216 -3.45435 -2.64108 -3.85984 0.12268 -0.10942 -0.40633 -0.08147 -0.67022 0.25469 -0.57605 -0.54944 -1.52439 0.23628 0.23699 1.24627 -0.47424 -1.02144 -1.95418 -0.74028 -0.39864 Table 78 - Methyl Acetamide, C1, Energy: -304.12207 C C O N C N H H H H H H H H H H 6.0 6.0 8.0 7.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.58441 0.69427 1.74947 0.59695 1.76516 -1.99959 -0.83598 -0.40745 -1.42418 1.48857 2.57168 2.14185 -2.20075 -2.83095 -1.91824 -0.29005 -1.75116 -0.98409 -1.55792 0.36353 1.18265 1.82192 -2.33883 -2.45155 -1.10112 2.22927 0.92838 1.03875 1.79949 1.47116 2.80368 0.80918 157 -0.33760 -0.60803 -0.89954 -0.50903 -0.75155 0.20970 -1.22328 0.48152 -0.08357 -0.61446 -0.05857 -1.76797 1.20697 -0.26089 -0.04643 -0.26822 Table 79 - Methyl Trifluoroacetamide, C1, Energy: -601.21078 C O N H C F F F C H H H N H H H 6.0 8.0 7.0 1.0 6.0 9.0 9.0 9.0 6.0 1.0 1.0 1.0 7.0 1.0 1.0 1.0 -0.82875 -0.80045 -1.85164 -1.77164 0.38976 1.35475 0.05156 0.90633 -3.06416 -3.77324 -3.50126 -2.85776 -1.40375 -1.44356 -0.42197 -1.87974 -0.56153 -1.77822 0.26359 1.27590 0.16714 -0.68472 0.89101 1.04679 -0.27987 0.53671 -1.03572 -0.74710 3.13233 3.29561 3.19100 3.91178 0.15288 -0.03209 -0.11855 0.05920 0.73801 1.08379 1.83585 -0.16086 -0.69897 -0.83466 -0.04201 -1.66533 0.42482 1.42829 0.16428 -0.02372 Table 80 - Methylcyanoformamide, Cs, Energy: -356.96347 N C C O N C H H N H H H H H 7.0 6.0 6.0 8.0 7.0 6.0 1.0 1.0 7.0 1.0 1.0 1.0 1.0 1.0 -1.83570 -0.74073 0.63723 1.62091 0.63991 1.90428 -0.26184 1.69447 -2.10406 -2.60719 -2.42393 -2.42393 2.49159 2.49159 -1.50407 -1.06034 -0.51063 -1.25131 0.83336 1.54385 1.33637 2.61327 1.92527 1.03890 2.44214 2.44214 1.28779 1.28779 158 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.81642 0.81642 -0.88526 0.88526 Table 81 - Methyl Succinimide, C1, Energy: -455.18368 C C N C C O O C N H H H H H H H H H H 6.0 6.0 7.0 6.0 6.0 8.0 8.0 6.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 0.52917 1.76042 1.38135 0.02188 -0.61973 -0.52583 2.90039 2.31425 4.66504 0.70344 0.40072 -1.38283 -1.13219 1.71974 2.93544 2.95198 4.30095 4.64012 5.64806 -1.26291 -0.83202 0.14771 0.45676 -0.44200 1.30054 -1.25874 0.81389 -1.64816 -1.07043 -2.34246 -1.05258 0.18323 1.38143 0.07381 1.49530 -1.62965 -2.61819 -1.39265 -0.86215 -0.08551 0.81472 0.76478 -0.27780 1.45442 -0.22177 1.71023 2.40933 -1.92439 -0.74822 0.21272 -1.01348 2.42535 2.21649 1.14227 1.45794 2.71474 2.35189 Table 82 - 1,3-Propanesultone, C1, Energy: -796.58767 C C C O S O O N H H H H H H H H H 6.0 6.0 6.0 8.0 16.0 8.0 8.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -3.84229 -2.58632 -1.99255 -3.07688 -4.53908 -5.30841 -5.08698 -6.48769 -4.58130 -3.62600 -1.87349 -2.85960 -1.44270 -1.34769 -7.38886 -6.39456 -6.55907 0.75631 0.41009 -0.81172 -1.58382 -0.86358 -0.98887 -1.34937 1.37912 1.35214 1.18153 1.23697 0.15626 -1.46802 -0.51631 1.55983 0.36670 1.72724 159 -0.06952 -0.85058 -0.13710 0.44439 0.19264 1.42085 -1.07484 -1.88668 -0.61505 0.91458 -0.87655 -1.87649 -0.81361 0.69471 -1.45017 -1.95086 -2.84003 Table 83 - N-Triflylpropanesultam, C1, Energy: -1660.66338 C C C N S O O S O O C F F F N H H H H H H H H H 6.0 6.0 6.0 7.0 16.0 8.0 8.0 16.0 8.0 8.0 6.0 9.0 9.0 9.0 7.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -6.53875 -5.68805 -4.38491 -4.08139 -5.42434 -5.21655 -5.69217 -2.78151 -3.01004 -2.32875 -1.54199 -1.96431 -0.37569 -1.38165 -5.52432 -6.80796 -7.40418 -6.18426 -5.49594 -3.56541 -4.52252 -5.44561 -4.61498 -6.17549 0.69446 1.16524 0.37091 0.30374 0.80259 2.20223 -0.19595 -0.57133 -1.08554 -1.40146 0.77269 1.65378 0.25072 1.39053 -2.52894 -0.36070 1.32330 0.97369 2.23828 0.86521 -0.64286 -2.32132 -2.89066 -3.30831 1.10123 2.26912 2.17801 0.73124 -0.28481 -0.64154 -1.31100 0.21035 -1.12846 1.32047 0.03454 -0.87233 -0.35214 1.21390 0.86250 1.19574 0.88038 3.22347 2.18494 2.70334 2.55743 -0.13276 1.14725 0.94198 Table 84 - Methyl Chloride, C3v, Energy: -555.73069 C H H H H H H Cl N 6.0 1.0 1.0 1.0 1.0 1.0 1.0 17.0 7.0 0.00000 -0.51302 -0.51302 1.02604 0.47000 0.47000 -0.94000 0.00000 0.00000 0.00000 0.88858 -0.88858 0.00000 -0.81406 0.81406 0.00000 0.00000 0.00000 160 1.91852 1.56196 1.56196 1.56196 -1.71285 -1.71285 -1.71285 3.70220 -1.32406 MP2(full)/6-31G(d) Geometries and Energies of Methyl Transfer Agents Table 85 - Methyl Mesylate, Cs, Energy: -702.21914 S O C C H H H H H H O O 16.0 8.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 8.0 8.0 -0.48793 0.74189 2.05024 -1.78750 -2.72724 2.75493 -1.70452 -1.70452 2.17258 2.17258 -0.48327 -0.48327 0.59518 -0.48079 0.14658 -0.60331 -0.04971 -0.68149 -1.21272 -1.21272 0.75409 0.75409 1.32550 1.32550 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.89869 0.89869 -0.89797 0.89797 -1.26391 1.26391 Table 86 - Dimethylsulfate, C1, Energy: -777.24377 C O S O C O O H H H H H H 6.0 8.0 16.0 8.0 6.0 8.0 8.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.94327 -1.26787 0.29230 0.41024 1.78363 1.08668 0.45285 -2.95766 -1.93144 -1.46981 1.69338 2.25226 2.34201 -1.54122 -0.26138 -0.32041 1.27809 1.75545 -0.78435 -0.95375 -1.34542 -1.85542 -2.28940 2.82986 1.52071 1.31405 161 0.02882 0.16975 -0.21263 -0.33405 -0.32370 0.91383 -1.51198 0.36629 -1.01440 0.66698 -0.46080 0.63166 -1.15122 Table 87 S O O O C C F F F H H H Methyl Triflate, C1, Energy: -999.28488 16.0 8.0 8.0 8.0 6.0 6.0 9.0 9.0 9.0 1.0 1.0 1.0 0.25159 0.07720 0.96943 0.81877 0.71707 -1.42711 -2.08031 -2.09407 -1.34499 1.21648 -0.32836 1.22784 0.41701 1.75046 0.13787 -0.58589 -0.15875 -0.29711 -0.24174 0.41557 -1.56608 -0.95207 -0.08190 0.79245 0.83473 0.28263 2.05924 -0.29120 -1.68227 1.03422 -0.13658 1.94346 1.43089 -2.23302 -1.97734 -1.81832 Table 88 - Methylfluorosulfonate, C1, Energy: -762.07625 S O O O C F H H H 16.0 8.0 8.0 8.0 6.0 9.0 1.0 1.0 1.0 -0.60047 -0.88595 0.30024 -0.27758 0.14692 -2.00395 0.32409 1.05819 -0.65152 0.32365 1.67695 -0.05308 -0.48448 -1.86719 -0.37244 -2.22029 -1.89960 -2.43862 162 1.04387 0.65859 2.10684 -0.28811 -0.10985 1.39800 -1.12209 0.48505 0.36382 Table 89 - Methyl TFSI (anti) C1, Energy: -1863.35495 N S S O O O O C F F F C F F F C H H H 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 9.0 9.0 9.0 6.0 9.0 9.0 9.0 6.0 1.0 1.0 1.0 0.17552 0.43900 -1.01820 -0.59558 -1.40403 1.17721 -0.77508 -2.41875 -3.45702 -2.05184 -2.74842 1.65825 1.12524 2.02968 2.72495 1.11958 0.54846 1.79542 1.67563 0.23493 -1.37755 0.70063 1.99214 -0.41878 -1.34640 -2.13839 1.03803 1.46415 1.99210 -0.06349 -1.89764 -1.81351 -3.15258 -1.08941 1.28464 2.14726 1.57006 0.87380 0.17590 0.62715 -0.93931 -1.45403 -1.77282 1.87842 0.42166 0.20971 -0.50953 1.07545 0.87714 -0.65200 -1.86777 -0.40263 -0.57754 0.63431 0.97208 -0.17071 1.47449 Table 90 - Methyl FSI, C1, Energy: -1388.93439 N S S O O O O F F C H H H 7.0 16.0 16.0 8.0 8.0 8.0 8.0 9.0 9.0 6.0 1.0 1.0 1.0 0.12598 0.17991 -1.35861 -1.09995 -2.21553 -0.96600 1.54614 -1.88279 -0.04132 1.24220 1.17936 2.17296 1.17679 0.85721 -0.74351 1.54537 2.82832 0.52898 -1.06044 -0.98483 1.85606 -1.46132 1.74979 2.63172 1.22368 2.03019 163 -0.43711 0.10271 -0.78570 -1.38785 -1.33205 0.91471 0.49304 0.69869 -1.30164 -0.04756 -0.68081 -0.24244 1.00543 Table 91 - Methyl MSI (anti) C1, Energy: -1269.22819 N S S O O O O C H H H C H H H C H H H 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 0.18569 -0.02526 -1.19470 -0.68432 -2.27211 -1.10049 1.31052 -1.63882 -2.51134 -0.79905 -1.87133 -0.59449 0.16590 -0.72473 -1.53800 1.39738 1.59453 1.28781 2.21657 0.23527 -1.44459 1.24290 2.59692 0.71724 -1.80835 -2.02036 1.02999 1.66215 1.35384 -0.02041 -1.68216 -1.30695 -2.75684 -1.15121 0.84298 1.77865 1.04332 0.14727 -0.72916 -0.89703 -0.57807 -0.77402 -1.41653 0.02067 -0.78488 1.12318 1.29904 1.73718 1.28927 -2.56249 -3.24863 -2.70243 -2.68209 -1.31282 -0.79397 -2.38254 -1.14029 Table 92 - Methyl MSA, C1, Energy: -682.37105 C N H S O O C H H H H H H 6.0 7.0 1.0 16.0 8.0 8.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 -0.46679 0.60191 1.51463 0.27618 -0.92965 1.54382 -0.15223 -0.14236 -1.33902 -0.73913 -0.39272 -1.02420 0.70035 -0.98040 -0.06732 -0.47669 1.19746 1.84720 1.90088 0.48393 -1.52469 -0.38197 -1.70185 1.30803 -0.16124 -0.07500 164 1.39584 1.00427 0.82176 -0.01451 0.49174 -0.18715 -1.59370 2.28386 1.65753 0.61542 -2.26707 -1.47872 -1.98104 Table 93 - Methyl FSA, C1, Energy: -742.23853 C N H S O O F H H H 6.0 7.0 1.0 16.0 8.0 8.0 9.0 1.0 1.0 1.0 -0.47591 0.77742 1.15876 0.91353 0.46777 2.15882 -0.24927 -0.31366 -0.69531 -1.31405 -1.08472 -0.37593 -0.49957 1.17616 1.28713 1.69964 1.89708 -2.13860 -0.97950 -0.70311 0.63071 0.35091 -0.58501 0.83132 2.19914 0.32390 -0.04507 0.40637 1.69189 0.04073 Table 94 - MeiprFSA, C1, Energy: -859.75289 C N C S O O F H H H C H C H H H H H H 6.0 7.0 6.0 16.0 8.0 8.0 9.0 1.0 1.0 1.0 6.0 1.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.80722 -0.79726 0.59710 -1.04159 -2.43176 0.05565 -0.86695 -1.59199 -1.80916 -2.78819 1.41497 0.43285 1.30135 2.23665 0.67519 1.52976 2.35797 1.64644 0.88618 -0.85772 0.15979 -0.15701 0.95216 1.33359 1.85854 -0.24180 -1.81629 -0.98511 -0.50207 -0.88805 -0.84411 1.07545 0.77053 1.56923 1.78580 -1.22087 -0.22725 -1.76480 165 0.47214 0.14298 0.57192 -1.25824 -1.36381 -1.51026 -2.35604 -0.01234 1.55533 0.16115 -0.48732 1.40886 1.12054 1.59903 1.86713 0.32701 -0.04512 -1.32439 -0.86857 Table 95 - Methyl Acetate, Cs, Energy: -267.59323 C C O O C H H H H H H 6.0 6.0 8.0 8.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 2.68274 1.23130 0.79414 0.44331 -0.96736 3.29585 -1.45462 -1.24089 -1.24089 2.90425 2.90425 -0.19511 0.19417 1.33134 -0.90962 -0.62359 0.70458 -1.59632 -0.05332 -0.05332 -0.80029 -0.80029 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.88859 0.88859 -0.88168 0.88168 Table 96 - Methyl Trifluoroacetate, Cs, Energy: C C O O C H H H F F F 6.0 6.0 8.0 8.0 6.0 1.0 1.0 1.0 9.0 9.0 9.0 2.68783 1.21056 0.82365 0.45829 -0.96475 -1.42554 -1.24147 -1.24147 2.97136 2.97136 3.46795 -0.18717 0.21533 1.36512 -0.88853 -0.63202 -1.61614 -0.06886 -0.06886 -0.92258 -0.92258 0.89761 -564.66942 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.89130 0.89130 -1.09071 1.09071 0.00000 Table 97 - Methyl Cyanoformate, Cs, Energy: -320.41939 C C O O C H H H N 6.0 6.0 8.0 8.0 6.0 1.0 1.0 1.0 7.0 1.37723 0.01780 -0.21986 -0.87322 -2.25169 -2.83598 -2.45105 -2.45105 2.49554 -0.16951 0.38172 1.57342 -0.61542 -0.17089 -1.08702 0.42337 0.42337 -0.54781 166 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.89167 0.89167 0.00000 Table 98 - Dimethylcarbonate, Cs, Energy: -342.62576 O C O O C C H H H H H H 8.0 6.0 8.0 8.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 1.32894 -0.01437 -0.67479 -0.51325 -1.95315 2.02034 3.07540 1.77468 1.77468 -2.20380 -2.34489 -2.34489 -0.45491 -0.45141 -1.46683 0.80765 0.84933 0.80664 0.54013 1.38405 1.38405 1.90791 0.35619 0.35619 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.89158 -0.89158 0.00000 0.88966 -0.88966 Table 99 - Dimethylurethane, C1, Energy: -322.79444 O C N O H C C H H H H H H 8.0 6.0 7.0 8.0 1.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.68705 -1.68319 -2.75114 -0.59305 -2.55723 0.57467 -3.98495 -3.99845 -4.82779 -4.08382 1.35224 0.85481 0.39661 2.70857 1.48714 0.69525 0.70542 -0.28473 1.45616 1.26905 1.35213 0.65521 2.26626 0.71044 2.14578 2.02120 -0.07422 -0.01669 0.27394 -0.26830 0.42707 -0.63476 0.76937 1.86158 0.44694 0.34329 -0.78915 0.16236 -1.55056 Table 100 - Methyl Acetamide, C1, Energy: -247.75036 C C N O C H H H H H H H 6.0 6.0 7.0 8.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 1.0 -2.63278 -1.32164 -0.21658 -1.26543 1.12159 -2.58313 -3.39653 -2.92879 -0.33358 1.69942 1.01750 1.65173 -0.41880 0.33824 -0.42195 1.54426 0.13121 -1.36572 0.21656 -0.62105 -1.41158 -0.25824 1.20998 -0.09100 167 -0.00008 -0.00008 0.25807 -0.24354 0.23094 0.54296 0.44900 -1.03287 0.42215 -0.61273 0.12255 1.16051 Table 101 - Methyl Trifluoroacetamide, Cs, Energy: -544.83515 C C O N F H F F C H H H 6.0 6.0 8.0 7.0 9.0 1.0 9.0 9.0 6.0 1.0 1.0 1.0 0.49401 -1.03527 -1.58336 -1.66595 0.94330 -1.12087 0.99271 0.99271 -3.11718 -3.42912 -3.51399 -3.51399 -0.00687 0.07587 1.17432 -1.11551 -1.29065 -1.96561 0.59792 0.59792 -1.16451 -2.20812 -0.66427 -0.66427 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 1.08865 -1.08865 0.00000 0.00000 0.88576 -0.88576 Table 102 - Methylcyanoformamide, Cs, Energy: -300.58450 C C O N N H C H H H 6.0 6.0 8.0 7.0 7.0 1.0 6.0 1.0 1.0 1.0 2.61562 1.19688 0.86457 0.34474 3.76025 0.71669 -1.09068 -1.38667 -1.38667 -1.59166 -0.18309 0.22863 1.41048 -0.82117 -0.47562 -1.76205 -0.59470 -0.03003 -0.03003 -1.56190 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.88642 0.88642 0.00000 Table 103 - Methyl Succinimide, Cs, Energy: -398.81698 N O O C C C C H H H H C H H H 7.0 8.0 8.0 6.0 6.0 6.0 6.0 1.0 1.0 1.0 1.0 6.0 1.0 1.0 1.0 -0.02919 2.26482 -2.32393 1.14492 -1.18736 0.76407 -0.76528 1.20551 1.20551 -1.19543 -1.19543 -0.03046 -1.07105 0.48307 0.48307 0.96204 0.70480 0.63450 0.21891 0.18999 -1.25124 -1.26945 -1.72785 -1.72785 -1.75653 -1.75653 2.41152 2.73425 2.78389 2.78389 168 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.87928 -0.87928 0.87916 -0.87916 0.00000 0.00000 -0.88801 0.88801 Table 104 - Methyl Chloride, C3v, Energy: -499.36908 C H H H Cl 6.0 1.0 1.0 1.0 17.0 0.00000 -0.51467 -0.51467 1.02934 0.00000 0.00000 0.89144 -0.89144 0.00000 0.00000 169 1.91773 1.56476 1.56476 1.56476 3.69460 MP2(full)/6-31G(d) Geometries and Energies of Anions Table 105 - Mesylate (-) C3v, Energy: -662.53310 C S O O O H H H 6.0 16.0 8.0 8.0 8.0 1.0 1.0 1.0 0.00000 0.00000 -0.72121 -0.72121 1.44242 0.51566 0.51566 -1.03132 0.00000 0.00000 1.24918 -1.24918 0.00000 -0.89315 0.89315 0.00000 0.15191 1.95361 2.31290 2.31290 2.31290 -0.20542 -0.20542 -0.20542 Table 106 - Methylsulfate (-) Cs, Energy: -737.57487 O S O C H O O H H 8.0 16.0 8.0 6.0 1.0 8.0 8.0 1.0 1.0 1.62257 0.50838 -0.81510 -2.05606 -2.83768 0.33447 0.33447 -2.15525 -2.15525 0.37580 -0.58274 0.48061 -0.21083 0.55435 -1.36721 -1.36721 -0.83840 -0.83840 0.00000 0.00000 0.00000 0.00000 0.00000 -1.24145 1.24145 -0.89199 0.89199 Table 107 - Triflate (-) C3v, Energy: -959.63081 C S O O O F F F 6.0 16.0 8.0 8.0 8.0 9.0 9.0 9.0 0.00000 0.00000 -0.72210 -0.72210 1.44420 0.62744 0.62744 -1.25489 0.00000 0.00000 1.25071 -1.25071 0.00000 -1.08676 1.08676 0.00000 170 0.20921 2.04431 2.35488 2.35488 2.35488 -0.29674 -0.29674 -0.29674 Table 108 - Fluorosulfonate (-) C3v, Energy: -722.42035 F S O O O 9.0 16.0 8.0 8.0 8.0 0.00000 0.00000 -0.71849 -0.71849 1.43697 0.00000 0.00000 1.24445 -1.24445 0.00000 0.29520 1.95804 2.26366 2.26366 2.26366 Table 109 - TFSI (anti)(-) C2, Energy: -1823.69893 N S S O O O O C C F F F F F F 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 6.0 9.0 9.0 9.0 9.0 9.0 9.0 0.00000 1.41490 -1.41490 1.41448 -1.41448 2.42973 -2.42973 1.80301 -1.80301 2.98193 -2.98193 0.86056 -0.86056 1.90555 -1.90555 0.00000 0.02268 -0.02268 0.48851 -0.48851 0.52762 -0.52762 -1.76885 1.76885 -1.93558 1.93558 -2.42617 2.42617 -2.33443 2.33443 0.87210 0.11185 0.11185 -1.27785 -1.27785 1.03850 1.03850 -0.01609 -0.01609 -0.64993 -0.64993 -0.70840 -0.70840 1.19802 1.19802 Table 110 - FSI (-)C2, Energy -1349.28297 N S S F F O O O O 7.0 16.0 16.0 9.0 9.0 8.0 8.0 8.0 8.0 0.00000 1.34747 -1.34747 1.79459 -1.79459 1.19740 -1.19740 2.37985 -2.37985 0.00000 0.31716 -0.31716 -1.15425 1.15425 1.11481 -1.11481 0.65209 -0.65209 171 0.90199 0.10686 0.10686 -0.44979 -0.44979 -1.10277 -1.10277 1.07274 1.07274 Table 111 - MSI (anti)(-) C2, Energy: -1229.53832 N S S O O O O C C H H H H H H 7.0 16.0 16.0 8.0 8.0 8.0 8.0 6.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 0.00000 1.39569 -1.39569 1.36940 -1.36940 2.46813 -2.46813 1.63809 -1.63809 2.58701 -2.58701 0.80040 -0.80040 1.66567 -1.66567 0.00000 0.05051 -0.05051 0.93808 -0.93808 0.27777 -0.27777 -1.59984 1.59984 -1.61728 1.61728 -1.83034 1.83034 -2.29000 2.29000 1.19069 0.37946 0.37946 -0.80902 -0.80902 1.36210 1.36210 -0.26067 -0.26067 -0.80014 -0.80014 -0.91775 -0.91775 0.58283 0.58283 Table 112 - MSA (-) C1, Energy: -642.63252 N H S O O C H H H 7.0 1.0 16.0 8.0 8.0 6.0 1.0 1.0 1.0 0.57006 1.48921 0.38777 -0.62712 1.66059 -0.39514 -0.57377 -1.34108 0.26538 -0.10099 -0.50957 1.03873 2.02699 1.59170 0.32181 1.11028 -0.13545 -0.43491 0.96594 0.77668 -0.09430 0.34904 -0.65248 -1.56133 -2.29622 -1.26657 -1.99171 Table 113 - FSA (-) C1, Energy: -702.52414 N H S O O F 7.0 1.0 16.0 8.0 8.0 9.0 0.56722 0.97222 0.52061 0.19381 1.54857 -0.85883 -0.19330 -0.42577 1.35184 1.84129 2.08606 1.81386 172 0.15548 -0.75429 0.22419 1.56672 -0.54186 -0.63337 Table 114 - Isopropyl FSA (-) C1, -820.03729 N C S O O F C H C H H H H H H 7.0 6.0 16.0 8.0 8.0 9.0 6.0 1.0 6.0 1.0 1.0 1.0 1.0 1.0 1.0 -1.16986 0.17441 -1.31598 -2.70600 -0.26330 -1.06232 1.10384 0.00632 0.84000 1.78322 0.16790 1.03613 2.03381 1.35160 0.61212 -0.12412 -0.43254 0.71546 1.11600 1.70878 -0.37167 -1.06709 -1.18778 0.77038 0.48393 1.18169 1.54388 -1.40766 -0.34254 -1.92015 0.10324 0.59246 -1.18332 -1.41984 -1.49458 -2.45844 -0.44532 1.37443 1.26476 1.74879 2.02338 0.52087 0.02768 -1.22369 -0.91840 Table 115 - Acetate (-) Cs, Energy: -227.85413 C C O O H H H 6.0 6.0 8.0 8.0 1.0 1.0 1.0 1.41889 -0.13047 -0.81068 -0.51302 1.70293 1.84816 1.84816 0.17015 -0.01033 1.05306 -1.21448 1.22674 -0.32279 -0.32279 0.00000 0.00000 0.00000 0.00000 0.00000 -0.87991 0.87991 Table 116 - Trifluoroacetate (-) Cs, Energy: -524.96954 C C O O F F F 6.0 6.0 8.0 8.0 9.0 9.0 9.0 -1.39578 0.15647 0.78477 0.51389 -1.96620 -1.96620 -1.85640 -0.13102 0.01014 -1.07386 1.21294 0.46561 0.46561 -1.41109 0.00000 0.00000 0.00000 0.00000 -1.08925 1.08925 0.00000 Table 117 - Cyanoformate (-) C2v, Energy: -280.73023 C C N O O 6.0 6.0 7.0 8.0 8.0 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -1.14998 1.14998 173 -0.02555 1.51982 -1.20979 2.00991 2.00991 Table 118 - Methylcarbonate (-) Cs, Energy: -302.90805 O C O O C H H H Table 119 O C O N C H H H H 8.0 6.0 8.0 8.0 6.0 1.0 1.0 1.0 0.61675 -0.57910 -1.62139 -0.34730 1.82340 2.63345 1.92596 1.92596 0.77336 -0.07927 0.59762 -1.30903 0.04709 0.78836 -0.59811 -0.59811 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.88132 0.88132 Methylurethane (-) Cs, Energy: -283.02333 8.0 6.0 8.0 7.0 6.0 1.0 1.0 1.0 1.0 2.05993 0.62469 0.37929 -0.16535 2.90753 3.93531 0.44585 2.75986 2.75986 0.49488 0.13235 -1.09266 1.17891 -0.62959 -0.24415 2.00010 -1.26547 -1.26547 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -0.88135 0.88135 Table 120 - Acetamide (-) Cs, Energy: -207.96859 N O C C H H H H 7.0 8.0 6.0 6.0 1.0 1.0 1.0 1.0 -0.02089 1.13446 0.06986 -1.22754 -1.02004 -1.21978 -1.21978 -2.16072 -1.42154 0.59077 -0.09681 0.76548 -1.65591 1.41923 1.41923 0.18718 0.00000 0.00000 0.00000 0.00000 0.00000 0.87947 -0.87947 0.00000 Table 121 - Trifluoroacetamide (-) Cs, Energy: -505.08677 C C O N F H F F 6.0 6.0 8.0 7.0 9.0 1.0 9.0 9.0 -0.45772 1.09048 1.51171 1.75147 -1.02417 1.06639 -0.98781 -0.98781 -0.03591 0.00643 1.19540 -1.13304 -1.29038 -1.89247 0.59077 0.59077 174 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 -1.08749 1.08749 Table 122 - Cyanoformamide (-) Cs, Energy: -260.84632 N C C O N H 7.0 6.0 6.0 8.0 7.0 1.0 2.12924 0.94410 -0.58354 -1.08719 -1.16580 -0.42817 -0.00457 0.01128 -0.00423 -1.15456 1.18112 1.89250 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 Table 123 - Succinimide (-) C2v, Energy: -359.07164 N O O C C C C H H H H 7.0 8.0 8.0 6.0 6.0 6.0 6.0 1.0 1.0 1.0 1.0 0.00000 -2.29645 2.29645 -1.11121 1.11121 -0.75752 0.75752 -1.20887 1.20887 -1.20887 1.20887 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 0.88031 0.88031 -0.88031 -0.88031 175 0.34286 -0.07498 -0.07498 -0.44605 -0.44605 -1.95649 -1.95649 -2.42744 -2.42744 -2.42744 -2.42744 REFERENCES 176 REFERENCES (1) Bruce, P.; Scrosati, B.; Tarascon, J. 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