M. _"’.'9fi«'-~2'”"’W”'V*mn-MM- on”- -—<---' -- _«. .00.-..v - - »- .ve .lq"v-~—.” -‘q.‘ ..”~‘-"--. ncqo.'m~~*~—_”--‘.v ' _ '7 *7 - V— vi.“ 4. " ‘2‘ 'l‘. 'o I 0' QIOO . ‘- I..‘.l't“ A 0F Momma (W) ’ ~ ‘ Thesis far the Degreeof M‘ S ; .MECHEGAN SYATE UNNER " 3‘ ‘ KERRY KfiRK f2 . 397i ' . . o v 5 s - v - . - , - -. . o . . ‘.- , ‘ ‘ '. - o - -a—O . - . g a t 0 U . .-' o n 1. o t -' - v .r‘ o'.‘ - r . O '- b _ - - - .“ ' - A'o- - ---' - no - - - . . . .‘ _ - - .. - ' *'- ‘ a a - , f l _ - - a.v > . - - ' ,. - V y . - _ . . — 9 5!. . .. , ‘ . v < - o . ~ . _ V. i- ‘ - 0' . o . . ' v . . — !_,. ‘ - . o . , . - --~l— . ‘ ' ‘ _ , . . - c ‘ o ' ‘ ' n - - o «n.- -- - . -, . n‘.| . v ’ ‘ - o e ' ’ X 0 l a k \ A. u‘ N N I . Q ‘ bfllt-H C c l 0‘- v "I N c n "l - o ' I . l u . . . I ~ I u 0 I . I o I I ,. .\ o 0 o . ‘ . n I v ’ ' O O o. A. . , - a - . ‘ . . - - . . a ' v , (' y , z'. r ' — r - . ' . - ' - I ’ ‘ ‘ ‘ I ' ‘ . ' I . ‘ v .‘ o . - . ' . ‘ o 5. a \ '- -- ' . ‘ ; , . ,.. ' _ — . , - -. . - ~ . a . 4 . .. u ’ a 1 . _ . ‘ . _' ' - . . . 4 .g a o . - c :6.“ ' ' 2., g 'r' 3'..." a' .-‘ ‘ ‘ 3 , ' ‘ - - ' . ‘ , ‘ ’ ' - ' - - , a . . . _ _. _ . _ f -' , . \c r a ' t 2.. . _-. I ’ n 11- ‘ O- > — ' . ‘ . _ 3 _ . ’ _ _ ‘ . o u. 'a‘ . u u : . ‘5 0 . 0‘ - ’ ‘.:..f '0‘ - ‘ . . - . I . T C - . . .1 ' 4 . -.o o ‘ . , t-- ' .‘ _ — - - . fl . , I ‘ - - I ' 3,.r. ' ‘- _ _ > _ . . o _ o ‘ ‘ . -. . ‘ ' A . I- . .‘ ~ ~ . . . . , . ‘ ' _ . - - , / o - - ' . . . {gaff ‘C. “ ‘~ LIBRA u g“ :33. ‘géeicnigan State 3.1 University r; 4.4; . _- .. --. “Inf-n ABSTRACT THE SYNTHESIS AND CHARACTERIZATION OF N,N,DIMETHYLFORMAMIDE COMPLEXES 0F NIOBIUM(IV) By Kirby Kirksey Adducts of the niobium(IV) halides with N,N,dimethylformamide (DMF) were prepared and studied by using physicochemical techniques. The complexes NbX4-ZDMF (X = Cl, Br) and NbI -8DMF were isolated. 4 Far infrared spectra were consistent with a trans stereochemistry. Various vibrational frequencies were assigned to the normal modes of a trans-MX4-L2 molecular species. Electronic spectra exhibited two d-d bands arising from transitions between an orbitally singlet ground state and the levels arising from a tetragonally perturbed excited 2Eg state. All the complexes were paramgnetic, with only the chloride showing axial symmetry. Theesr~ spectrum of the solid iodide complex exhibited niobium hyperfine coupling as did solutions of all the complexes. A simple molecular orbital calculation was done by using the parameters derived from esr data of the chloride complexes. THE SYNTHESIS AND CHARACTERIZATION OF N,N,DIMETHYLFORMAMIDE COMPLEXES OF NIOBIUM(IV) By Kirby Kirksey A THESIS Submitted to Michigan State University in partial fulfillment of the requirements . for the degree of MASTER OF SCIENCE l97l ACKNOWLEDGEMENTS The author wishes to express his sincere appreciation to Professor James B. Hamilton for his patience, guidance, and encouragement during the course of this study. Special thanks go to Professor Eugene LeGoff, whose discussions on the nuances of organic chemistry were invaluable. Appreciation is also extended to Professor Robert E. McCarley, Iowa State University, for providing far infrared spectra of the complexes. The preparation of NbI4 by Mr. Roger McGinnis is gratefully acknowledged. ii TABLE OF CONTENTS INTRODUCTION Review of Previous Work Purpose of this Study EXPERIMENTAL Materials Analytical Determinations Physical Measurements Synthesis RESULTS AND DISCUSSION Preparation and Properties of the Complexes Vibrational Spectra Electronic Spectra Electron Spin Resonance Spectra SUMMARY AND CONCLUSIONS BIBLIOGRAPHY APPENDIX Experimental Esr Parameters from Solution Spectra —I TO 10 ll l2 l4 l4 l5 23 31 47 48 50 Table Table Table Table Table Table Table Table Table Table Table Table 9. LIST OF TABLES Infrared Spectra of DMF (4000—600 cm'1) Infrared Spectra of NbX4-nDMF Complexes (4000-600 cm'1) Observed Carbonyl Frequencies in DMF Complexes Far Infrared Spectra of DMF (600-50 cm“) Far Infrared Spectra of DMF Complexes Absorption Maxima of the DMF Complexes Parameters Derived from Electronic Spectra Esr Parameters from Solid and Solution Spectra Magnetic and Bonding Parameters for NbCl4-ZDMF 10. Experimental Esr Parameters for NbCl4-ZDMF in DMF ll. l2. Experimental Esr Parameters for NbI Experimental Esr Parameters for NbBr4-ZDMF in DMF 4'8DMF in DMF iv T6 17 19 21 22 27 30 32 45 51 52 53 Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure Figure lO. ll. l2. 13. LIST OF FIGURES Apparatus for Determination of Electronic Spectra Electronic Spectra of NbCl4-2DMF in DMF Electronic Spectra of NbBr4-ZDMF in DMF Electronic Spectra of NbI4-8DMF in DMF Energy Level Diagram for a Tetragonal Distorted Metal Complex Esr Esr Esr Esr Esr Esr Esr Esr Spectrum Spectrum Spectrum Spectrum Spectrum Spectrum Spectrum Spectrum of of of of of of of of NbCl -2DMF in DMF at Room Temperature NbCl ~2DMF in DMF at 77°K NbBr -ZDMF in DMF at Room Temperature NbBr '2DMF in DMF at 77°K b-b-b-b NbI4-8DMF in DMF at Room Temperature NbI °8DMF in DMF at 77°K 4 Solid NbI4-BDMF at Room Temperature Solid NbI '8DMF at 77°K 4 12 24 25 26 29 35 36 37 38 39 40 41 42 INTRODUCTION Except for niobium tetrafluoride, the tetrahalides of niobium are diamagnetic polymers, whose basic unit may be represented as Nb2X8 (l-3). They react with certain donor ligands to give rise to paramagnetic species in which the metal-metal bond has been cleaved. With a few donor ligands, the metal-metal bond is retained. The resulting species are diamagnetic or weakly paramagnetic. The types of compounds that are commonly found are as follows: a) Six coordinate, mononuclear, neutral species; donor atoms: oxygen, nitrogen, phosphorus, and sulfur. b) Six coordinate, mononuclear, anionic species; donors: alkoxo, halo, and 0x0 l1gands. c) Six coordinate, polynuclear, neutral species; donors: alkoxo anions and thioethers. d) Eight coordinate, mononuclear, neutral species; donor atoms: sulfur, oxygen, and arsenic. These four classes of complexes represent the typical observed chemistry of the niobium tetrahalides. Review of Previous Work McCarley and Torp (4) investigated pyridine (py) adducts of the tetrahalides. The composition of the adducts was NbX4-2py. The complexes were not very soluble in pyridine and were insoluble in other solvents. Visible spectra were obtained for all three complexes in pyridine. The visible data for the iodide were ambigious due to the possibility of reduction of the tetraiodide complex to a l triiodide complex (NbI3py3). The iodine obtained as the oxidation product could ionize in pyridine to yield the triiodide ion (13-). . q, _ - Solut1ons of NbCl4 gave 0 x — 20.6 kK, Emax - lOlO :_50, and ma '1, _ ‘ ___ "J : NbBr4 gave Vm x — 20.7 kK, e x 720 :_50, and vmax 22.8 kK, a ma 5 x = 680 :_50. Magnetic susceptibilities obey Curie's Law over ma a range of 77-298°K. The magnetic moments were l.37, 1.26, l.58, and 1.05 B M for the chloro, bromo (green and red), and iodo complexes respectively. The conclusion was made that the greatest distortion from octahedral symmetry was exhibited by the chloro complex since it had the largest effective moment. During the same period, Fowles and co-workers (5) reduced the pentahalides chemically to form complexes with the ligands 2,2'-bipyridyl, l,lO-phenanthroline, and y-picoline. The complexes were studied by diffuse reflectance and they were relatively insoluble except in excess ligand. Machin and Sullivan (6) investigated the reactions of triphenylphosphine and thiourea (TU). A product of composition NbCl4-3/2 Ph3P was isolated from a mixture of triphenylphosphine, NbCl4, and benzene. It was postulated that the species was a dimer, bridged by a single phosphine molecule. This formulation can account for the weak paramagnetism that was exhibited, but this is not the only model applicable. The thiourea adducts appeared to be octahedral monomers with the iodide adduct being a lzl electrolyte with the formula [Nb(TU)313]I. The bromide and chloride adducts were complexes of the type NbX4-2L. The complexes were soluble in acetonitrile. This may account for the lack of interpretable solution spectra since acetonitrile probably effectively competes with thiourea as a donor. Fowles and co-workers (7,8) studied the stereochemical, magnetic, and spectral properties of several niobium(IV) halide adducts as well as the complex anions NbCl62' and NbBr62'. The ligands employed were acetonitrile (ac), tetrahydrofuran (thf), tetrahydropyran (thp), dioxane (diox), 2,2'-bipyridyl (bipy), l,lO-phenanthroline (phen) and acrylonitrile (arc). The monodentate and bidentate ligands formed 2:l and l:l donor-tetrahalide complexes respectively. 063 configurations were determined on the basis of the characteristic four absorption bands in the far infrared. These are 0(Nb-X) bands which transform according to the four modes of symmetry 2A1+81+BZ. The magnetic moments covering a temperature range of 93°K to 3l3°K were comparable to the previously reported values of l.O-l.6 B.M. An attempt to fit the moments to calculated data of Figgis (9) resulted in only one unique fit, that being the NbX4~bipy complex. One does not expect to find good agreement with Figgis' data when there are only small variations in peff with respect to temperature. Diffuse reflectance and solution spectra were obtained on the hexahalo salts. The observed maxima were 19.4 kK and 24.5 kK for the chloro complex and l5.9 kK and 2l.5 kK for the bromo complex. These bands were assigned as d-d transitions. Fowles and co-workers criticized the conclusions of McCarley, et aZ.(4) that large “eff only implied large distortion from octahedral symmetry. They noted that “eff’ properly considered, approaches spin-only values not only for large values of A (distortion parameter) but also as the covalent character of the metal-ligand bond increases. Reactions of NbCl4 and NbX4 (X = Cl, Br, and I) with triethylamine and N,N,N',N'-tetramethylethylenediamine respectively were studied by e11 Brown and Newton (lO). With triethylamine, lzl adducts were isolated which were diamagnetic, indicating the metal-metal bond of the tetrahalide had been retained. The diamine gave products of the formula MX4-B. The visible spectra of the bidentate complexes were interpreted by using a tetragonally distorted octahedron model. Reductions of NbCl5 in concentrated hydrochloric acid solutions by using a mercury electrode were reported by Cozzi and Vivarelli (ll). At l3 N, the solutions were red-orange. As the HCl concentration was lowered, the solutions turned blue. The niobium(IV) species in blue solutions gave absorption maxima at 14.3 kK and the species present was believed to be NbOCl42'. Compounds which were assumed to be of the type NbOX42- (X = Cl, F) as well as NbOacac2 were investigated by the esr method (l2). The 2 equality of A = 26 where 6 is the splitting of the ground state T 29 level and A is the splitting between the resulting ground orbital singlet level and the highest singlet arising from the split 2 2.. Eg level was applicable only to NbOF4 Electrolytic reduction of NbCl5 in HCl-saturated alcohols yielded 52' (l3). The compounds exhibited complexes of the formula Nb(OR)Cl spin-only paramagnetism for the d1 ion. The magnetic susceptibilities were measured as a function of temperature. Curie-Weiss behavior was observed in all cases. Esr spectra were obtained for the methoxo complex at room temperature and 77°K (l4). A molecular orbital treatment was performed to interpret the experimental esr parameters in terms of the bonding. The molecule was assigned C4v symmetry. By using basically the same technique as Wentworth and Brubaker (l3), Lardon and Gunthard (15, 16) studied esr spectra of complexes which 62- in solution. Unlike the former authors, who they thought were NbCl obtained solution electronic data that were comparable to solid state data for the complexes, Lardon and Gunthard did not isolate their complex species. They did however reconstruct their experimental esr spectra, and the final data obtained suggest strongly that their solution species was Nb(OR)0152' as in the case of Brubaker, et al. (17). Alkali metal and ammonium hexachloroniobates(IV) were investigated by Morozov and Lipatova (18). These compounds were prepared by using concentrated hydrochloric acid solutions instead of acetonitrile as Fowles (7) had used. No magnetic data were presented by these authors, but X-ray powder patterns showed no lines for the tetrachloride and alkali metal or ammonium chlorides. The structure was isomorphous with K2PtC16. Machin and Sullivan (19) also reported substitution reactions of the tetrahalides with potassium cyanate, thiocyanate, cyanide, and borohydride, and sodium diethyldithiocarbamate (Nadtc). The stoichiometry of the products was NbZ4_nXn (n = 0-4), with complete displacement occurring only with dtc. The magnetic susceptibilities of the complexes were small, being in the range of 40—50 X 10"6 c.g.s., suggesting that a bridged metal-metal bonded structure analogous to the tetrahalides had been obtained. Wentworth and Brubaker (20) prepared complexes in which ethoxide was substituted for chloride. NbCl5 was electrolytically reduced to Nb(IV) in HCl-saturated ethyl alcohol. Pyridine (py) was then added to this mixture. A complex of the composition [NbC1(OC2H5)3(py)]2 was isolated. The completely substituted ethoxide complex was prepared by the reaction of the pyridine complex with sodium ethoxide in ethyl alcohol. Both complexes were diamagnetic and polymeric in structure. Monodentate alkyl sulfides (21,22) reacted with the tetrahalides to give three types of adducts. Diadducts were formed by the cyclic thioether tetrahydrothiophene (tht) and by methyl sulfide. The tht adducts were paramagnetic with molar susceptibilities exhibiting a Curie Law dependence on reciprocal temperature. Monoadducts found for methyl sulfide were weakly paramagnetic. The authors attributed this magnetic behavior to moderate to strong interactions between the single electrons on neighboring niobium centers. Ethyl sulfide adducts were monoadducts and diamagnetic, suggesting that a metal- metal bond was present. Eight coordinate complexes have been reported by Nyholm and coworkers (23). The bidentate o-phenylenebisdimethylarsine (diars) forms complexes of the type NbX4—2diars. The complexes could be prepared from NbX5, NbX4, or NbOX3. The uv-visible diffuse reflectance spectra exhibited four maxima. The magnetic data were not reproducible due to dependence on tube packing. Esr data substantiated the susceptibilities with a magnetic moment of 1.69 B M being found for the chloride. The structures of the chloride and bromide complexes were isomorphous with known eight coordinate dodecahedral complexes (24). Additional eight coordinate complexes were prepared by using 4-methy1-diarsine and ethyldiarsine (25). Complexes were isolated that were similar to the previously mentioned eight coordinate complexes. The magnetic data supported the values expected for a single d electron in an orbitally non-degenerate ground state. There was some uncertainty associated with the solution electronic spectra due to the complexes having been dissolved in donor solvents such as pyridine or acetonitrile where addition reactions are expected to occur. Beta-diketones such as acetylacetone formed substitution complexes of the composition NbB4, which were eight coordinate (26). The effective magnetic moments ranged from 1.51 to 1.66 B M. Bradley and co-workers used two methods for preparation of completely halogen substituted derivatives of niobium tetrachloride (27,28). The complex with R = CH could be prepared by adding carbon 3 disulfide to a cyclohexane solution of the tetra or penta dimethylamido derivative of niobium(IV). The reduction of the pentakisdimethylamido complex gave an oxidation product of tEtramEthylthuiram disulfide [(MeZNCSZ)2]. Higher alkyl derivatives were prepared from the tetrakisdialkylamido complexes. Bradley and Sullivan (19) have proposed eight coordination for these complexes. (The tetrakis dialkylamido comp1exes may be a new class of paramagnetic four coordinate compounds of niobium(IV).) Neither author was able to determine whether the complexes were dodecahedral or antiprismatic. Hamilton and McCarley (29) reported a proposed eight coordinate complex for the bis adduct formed by 1,2-dimethy1thioethane(dth) with the tetrahalides. Data supporting a dodecahedral structure were the characteristic shifts of30—40 cm-1 by the bands due to metal- halogen stretching vibrations in the far infrared. Magnetic moments were obtained from the Curie plots of magnetic susceptibilities. Epr data were obtained for the powered chloride complex. The magnetic moment of 1.67 B M calculated from was only slightly higher than the 1.60 B M observed experimentally. There is one factor that has prevented an extensive study of the niobium tetrahalides, that being the finding of a suitable solvent for the complexes. Complexes that have been prepared tend to be insoluble in their donor ligands as well as a variety of non-donor solvents. To find a solvent for studying the solution chemistry of Nb(IV), and the isolation of well characterized comp1exes would greatly enhance the knowledge of d.I systems. N,N—dimethylformamide (DMF) had been used to dissolve NbCl4 by Gut (30). He reported the tetrachloride dissolved readily to give a deep blue solution containing Nb(IV). Several workers had 2‘ in solution. No reported that the blue colors are due to NbOCl4 complex was isolated by any of these authors. Coordination complexes of the group IV metals and DMF have been reported. Archambault and Rivest (31) found complexes with titanium tetrahalides which were 2:1 adducts for the chloride and bromide, and 8:1, 4:1, and 2:1 adducts for the iodide. The 4:1 and 8:1 adducts could be decomposed to the 2:1 adducts before complete decomposition occurred. The authors proposed that the additional molecules of DMF were not coordinated, but were being held in the secondary sphere of the metal nucleus. Infrared data exhibited the characteristic shift in the carbonyl stretching frequency to lower energy that has been found for other DMF complexes (32). Clearfield and Malkiewick (33) reported 2:1 adducts of DMF by reaction with zirconium tetrachloride. In excess ligand, the product was unchanged. Infrared spectra indicated coordination of the ligand through the oxygen. The isolectronic MoCl5 abstracted oxygen from DMF upon reaction to form MoOCl4' (34). This was typical of the reaction of MoCl5 with oxygen donors. Purpose of this Work In the present study, the reactions of niobium tetrahalides and DMF are investigated. As a first step is the establishing the suitability of DMF as a solvent for the study of niobium(IV) in solution. Complexes have been isolated and characterized both as solids and in solution. The results are interpreted relative to previously reported results on DMF-metal tetrahalide complexes and other complexes of niobium(IV). EXPERIMENTAL Due to the oxygen and water sensitivity of the compounds, all the compounds were handled in a Vacuum Atmospheres Corporation nitrogen filled drybox, maintained ca. 1 ppm water and oxygen or under high vacuum. Materials Niobium pentachloride and high purity niobium metal were purchased from Alfa Inorganics. Niobium pentabromide, niobium pentaiodide, and the three tetrahalides were prepared by using procedures previously described (4,35). N,N-dimethylformamide (DMF), purchased from Eastman Kodak, was purified by using the procedure given by Leader and Gormley (36) with the following modification. The DMF was purged with dry nitrogen before being distilled under dry nitrogen at atmospheric pressure onto a mixture of KOH and CaO. Analytical Determinations Microanalyses were preformed by Galbraith Laboratories, Inc., Knoxville, Tennessee. The elements determined were, C, H, X (X = Cl, Br, and I), and Nb. Molecular weight was determined for the bromide complex in DMF. Preliminary analyses were performed to determine niobium and halogen. The niobium was determined gravimetrically as niobium(V) oxide. Samples of the complexes were added to aqueous ammonia and 11E Si ll heated for two hours. After the samples cooled to room temperature, they were acidified with dilute nitric acid. The white anhydrous niobium oxide was filtered on ashless filter paper, washed three times with dilute nitric acid, and ignited at 900°C for two hours. The filtrate was analyzed for halogen by the Volhard method. Physical Measurements Electron Spin Resonance Spectra All esr spectra were obtained on solutions and powders at room temperature and -l96°C by use of a Varian Model E-4 spectrometer with an operating frequency range of 8.8 to 9.6 GHz, and equipped with a field dial - regulated magnet. Electronic Spectra Solution spectra were recorded using a Cary Model 14 spectrophoto— meter. Cylindrical fused silica cells, 0.5 cm long and adapted for use at low pressure (Figure 1), were used (4). Powdered samples and saturated solutions were loaded in the drybox. The cell assembly was then evacuated to ca. 10'5 torr. After sealing off the cell assembly, solvent and/or solutions of various concentrations could be distilled through a medium porosity frit into the cell. Vibrational Spectra Solid state infrared spectra were obtained by use of a Perkin- Elmer 457 (4000-250 cm']) spectrophotometer. Samples were prepared in the drybox and were mounted as nujol mulls between sodium chloride plates. Mulls were prepared immediately before measuring the spectra. Far infrared spectra were obtained by using a Block Engineering Company Model-FTS 16 (3900-20 cm-I) far infrared spectrophotometer. High density polyethylene was used for windows. 12 ’ “DONG" VICUUM IMUHFOLO STOPCOCK BALL- SOCKET JOINT SEAL OFF HERE AFTER LomyNG OUARTZ-PYREX GRADEO SEAL MDuNG CHAMBER QUARTZ spannoaxrv ceu. Figure 1. (Taken from Reference 4) Apparatus for determination of electronic spectra. Synthesis The preparative procedure varied only slightly from one halide to the other. The appropriate halide (2-3 9), 50-100 m1 of DMF, and a magnetic stirring bar were introduced into a round bottom flask. This flask was evacuated to ca. 10-5 torr, and after extensive outgassing, was isolated from the vacuum system. The mixture was stirred for several days at room temperature. With NbCl4, a yellow saturated solution and a brown-yellow precipitate were obtained. The precipitate was recovered by filtration, extracted with DMF, filtered again, washed with dry pentane, and dried in vacuo. was ' WES fill W08 13 Anal. Calcd. for NbCl4°203H7N0z Nb, 24.4; C1, 37.2; C, 18.9; H, 3.7. Found: Nb, 24.7; C1, 37.0; C, 19.3; H, 3.7. M.P., 139-142°C. An opaque green solution was obtained with NbBr4. A bright green solid was present in the mixture. The bromide product was recovered as a pale violet solid by using the same procedure used for the chloride. Anal. Calcd. for NbBr4-ZC3H7NO: Nb, 16.6; Br, 57.2; C, 12.9; H, 2.5. Found: Nb, 16.8; Br, 54.0; C, 12.8; H, 3.0. M.P., 230-233°C. Molecular weight in DMF: Calcd. for NbBr 558. Found, 506. 4'2DMF, A similar opaque green solution was found with NbI4. The solution was homogeneous, with no solid being present. The iodide solution was filtered and a green crystalline solid was recovered from the filtrate by removal of excess DMF in vacuo. This product was then washed with dry pentane and dried in vacuo. 7 Anal. Calcd. for [NbI4-BC3H7NO]: Nb, 7.8; I, 42.8; C, 24.3; H, 4.8. Found: Nb, 7.4; I, 43.4; C, 24.0; H, 5.0. M.P., 130-132°C. An attempt to prepare the expected bis adducts of the tetrahalides with triphenylphosphine (Ph3P) was made. Compounds of the composition NbX4-3/2 Ph3P (X = Cl, Br) were found. This work was subsequently terminated following the publication of the synthesis of NbC14°3/2 Ph P 3 by Machin (6). RESULTS AND DISCUSSION Preparation and Properties of the Complexes The reactions of the niobium(IV) halides with N,N-dimethylformamide (DMF) proceed according to equations 1 and 2. NbX4 + DMF + NbX4(DMF)2 (I) (X = Cl, Br) NbI4 + DMF + NbI4(DMF)8 (2) The complexes were isolated as powders or as crystals in the case of the iodide. There was no evidence for formation of any complex other than a bis adduct for the chloride and bromide as indicated by the analytical data and the molecular weight of the bromide complex. The unusual composition of the iodide will be discussed later. All complexes were air and water sensitive as indicated by the color changes on exposure to such conditions. The chloride and bromide were moderately soluble in excess DMF while the iodide complex completely dissolved in DMF. At the respective melting points, the compounds decomposed. The chloride and iodide reactions gave compounds similar in color to their solutions. The bromide complex gave rise to unusual behavior with respect to the color of the complex. As long as the bromide product was not dry, the compound was bright green. Under dynamic vacuum, the color changed to lilac over a period of twelve hours. 14 15 The product reverted to the green solid on the addition of DMF. If the opaque green solution, under vacuum, were heated to ca. 60°C, the solution changed to a purplish color, which faded to the original color at room temperature. These unusual color changes point to a possibility of both cis and trans isomers being formed as was found in the bromide-pyridine complex (4). The unusual stoichiometry of the iodide complex has been observed in similar systems. As discussed previously, Archambault and Rivest (31) found 8:1, 4:1, and 2:1 adducts of DMF and titanium tetraiodide. Fowles and Nicholls reported an ammine complex with the composition TiI4r8NH (37). Both authors proposed that the 3 complexes were bis adducts, with the extra molecules of ligand being held in the secondary sphere of influence of the metal nucleus. Data obtained from esr in this study support thisproposal. Vibrational Spectra Infrared spectra (4000-600 cm") DMF has been studied in the infrared region by Kaufmann and Leroy (38), who also assigned the various vibrations using a normal coordinate analysis. The assignments and the results from a study of DMF in this work are presented in Table 1. Infrared spectral data of the complexes are presented in Table 2. There have been several workers who have studied DMF as a ligand and coordinated in metal complexes (31-33). There was some conflict as to the assignment of the bands other than the band 1 occurring ca. 1680 cm' . This band has generally been assigned as 0(CO). On coordination, this band has been shifted to lower frequencies. 16 Table 1 Infrared Spectra of DMF (4000-600 cm-l) 0(cm—1) Assignment This Work Kaufmann et al. (38) 0(CO) v(CN) 6(CH) \KCN) v(CO) 6(CH) 68(CH3) 6a(H3C-N-CH3) I'Rocking" CH3 in the plane I _ _ Vs‘H3C N CH3) 6(OCN) Unassigned bands 1692 1510 1410 1261 1088 872 660 1725 805 w(sh) 1679 s 1490 m 1409 m 1250 s 1095 s 866 m 660 s 5, strong; m, moderate; w, weak; sh, shoulder; a, assymmetric, s, symmetric 17 Table 2 Infrared Spectra of NbX4°nDMF Complexes (4000-600 cm'1) v(cm']) Cl Br I 1647 S(b) 1647 S 1645 S(b) 1409 m 1408 m 1238 ms 1370 m 1375 m 1148 m 1258 m 1355 m(sh) 1060 m 1050 S(b) 1259 m 860 wm 1089 wm(b) 795 S 1015 800 m s, strong; m, moderate; w, weak; b, broad; sh, shoulder 18 Raman spectra and force constant calculations performed by Kaufmann (38) show that DMF may be depicted by the resonance forms ir1 equation 3, with the polar structure (8) being the predominant Species 0 CH 0- CH \\ /3 \\ +/3 C -——-N C ::::N (3) / \ / \ H CH3 H (A) (B) In the complexes of the niobium tetrahalides, a shift in the CH3 carbonyl vibration is observed. These results are summarized in Table 3 with the frequencies that have been reported for similar complexes. It is clear that coordination of DMF has occurred via the carbonyl oxygen in these complexes. The intense band which occurs in free DMF at 660 cm'1 was assigned as 6(0CN). In the complexes, this band is shifted to higher frequency which is expected as the bond order of the C-N bond is increased. 1 and 800 cm'1 This band appears at 795 cm' in the chloride and bromide respectively. It should be noted that many bands observable in the chloride and bromide complexes are not observable in the iodide complex. The broadness of the bands as well as the absence of many bands support the theory that the iodide complex is surrounded by free DMF molecules. There were no bands that could be attributed to free DMF as was found by Rivest (31) in the 8:1 adduct of DMF and titanium tetraiodide. 19 Table 3 Observed Carbonyl Frequencies in DMF Complexes Complex v(CO)(cm-]) Av(CO)(cm']) NbCl4 1647 32 NbBr4 1647 32 NbI4 1645 34 TiCl4 1643 (31) 36 TiBr4 1642 (31) 37 1114 1653 (31) 26 ZrCl4 1658 (33) 21 Numbers in parentheses refer to references 20 Far Infrared Spectra (600-50 cm-li Far infrared spectra were recorded for the uncoordinated ligand. These data are presented in Table 4 with the data and assignments obtained by Kaufmann (38). In this work, additional weak bands were found that were not assigned. The most prominent peak in the region of investigation is that at ca. 360 cm—1. Halogen sensitive bands are found when the spectra of the complexes are compared. Table 5 lists the spectral data with the respective tentative assignments. In the chloride, the band at 318 cm'] has been assigned as a 0(Nb—Cl) mode. Although this assignment approaches the lower limit of the range typically found for 0(Nb-Cl) 1 (7,8, 21, 22), in six coordinate niobium complexes, 410-320 cm— the shape of the band, its relative intensity, and its absence in pure DMF and NbBr4-20MF supports this assignment. The shoulder at 282 cm-1 could be indicative of another 0(Nb-C1) mode, but because it is weak and also appears in the bromide spectrum such an assignment 1 in the chloride and is not likely. The strong peak ca. 425 cm- bromide which is not present in pure DMF, is assigned as 0(M-DMF) due to its intensity relative to the expected ligand vibration at 360 cm']. This vibration cannot be the 6(H3C-N-CH3) mode due to the general appearance of the peak. By using the ratio 0(Nb-Br)/0(Nb-C1) = 0.76 that was found for the monodentate thioether adducts of NbX4 (22), one expects to find a 0(Nb-Br) mode ca. 242 cm-]. A band not present in DMF nor in the chloride complex is found at 248 cm-1 and is assigned as 0(Nb-Br). 1 The ligand vibration at 362 cm" did not shift as found in the chloride, from that present in the uncoordinated ligand. 21 Table 4 Far Infrared Spectra of DMF (600-50 cm-1) 0(cm-1) Assignment This Work Kaufmann et a1. (38) 6(H3C—N-CH3) 405 w 405 w 6(H3C-N-C) 362 s 360 s Unassigned 437 w(sh) 322 w 227 w 203 vw 5, strong; m, moderate; w, weak; sh, shoulder; b, broad; v, very Far Infrared Spectra of DMF Complexes Compl 22 Table 5 ex [0(cm_])] Assignment Cl Br I 0(M-L) 428 S 425 S 430-400 S(b) 6(H3C-N-C) 377 s 362 s v(Nb-X) 318 S 248 S Unassigned 282 m(sh) 309 m 320-310 m(b) 178 wm 285 m(sh) 280—260 S(b) 125 w 165 m 103 w s, strong; m, moderate; w, weak; b, broad; sh, shoulder 23 Due to the anamolous composition of the iodide complex, the reoccurring broadness of the bands is observed in the far infrared. The ratio of V(Nb-I)/6(Nb-Cl), calculated as 0.56 (22), predicts a 0(Nb—I) mode ca. 178 cm-1. No bands occur in this region that may be assigned as 0(Nb-I). This observation may point to a possible composition in which six DMF molecules are in the inner coordination sphere and the iodide atoms are held along with the remaining two DMF molecules in the outer sphere of influence. For complexes of composition MX4-2L, it is possible to form cis or trans isomers. The cis complex will be approximately C2v symmetry with four 0(M-X) modes being allowed in the infrared (2A1 + B1 + B2). For a trans complex, which is D4h symmetry, only one 0(M-X) is allowed (Eu) (39). In both the chloride and bromide complexes, there is only one band which may unambiguously be assigned as 0(Nb-X). This points to a trans configuration for these complexes. The shoulders which are present on the 0(Nb-X) band in the spectra of both complexes, coupled with the obviOUS‘color changes that occur with the bromide complex, may be indicative of small amounts of cis isomers being present. Evidence to further support a trans configuration is found in the epr data which will be discussed later. Electronic Spectra Visible and near infrared spectra were studied by using the technique described in the experimental section. These studies were carried out with DMF solutions of the complexes. The spectra and the frequency maxima are given in Figures 2, 3, and 4 and Table 6 respectively. 24 Absorbance (arbitrary units) ’-——-—I—N '> ”—"_-d Figure 2. \ \ \ \ \ \ \\‘/’\\ \ \ \\ \ \ \ \ / / / \ \ \ x.- 1 \1 \ 1 " “" 1 1 1 400 500 600 700 300 900 x mm) Electronic Spectra of NbCl4-ZDMF in DMF. Molar concentrations: (1) 0.0727; (2) 0.00665; (3) 0.0011. 25 Absorbance (arbitrary unitS) Figure 3. o 1 \. \“fi. \ \0‘ fan. . . 2 ‘_._--' "\ ____. /”\\.\T.~ 3" l I l l l I 400 500 600 700 800 900 Mm") Electronic Spectra of NbBr4-20MF in DMF. Molar concentrations: (1) 0.0119; (2) 0.00187; (3) 0.00109. 26 Absorbance (arbitrary unitS) Figure 4. 2 1 3 \u.“ .\k L J l J 1 l 400 500 600 700 800 900 Mom) Electronic Spectra of NbI4-80MF in DMF. Molar concentrations: (1) 0.021; (2) 0.0144; (3) 0.0118. 27 Table 6 Absorption Maxima of the DMF Complexes Complex Peak Positions (kK) (extinction coefficients in parentheses) NbC14-2DMF 12.9(l.65) 22.9(271) 24.4(382) in DMF NbBr4-20MF 13.3(112) 15.8(202) 26.3(750) in DMF NbI4r8DMF 13.5(76) 16.1(103) 20.4(132) 28.6(243) in DMF 28 Far infrared data have suggested that the chloride and bromide complexes have trans configurations. Assuming D4h symmetry for the MX4-2L complexes, the energy level diagram is expected to split as shown in Figure 5 (40). Parameters derived from the spectra are listed in Table 7. The relative energies of 2Alg and 2B19 may be reversed. The orbital singlet level, 2B29, is shown as lower in energy than 2E9 and this is consistent with the epr results which are subsequently discussed. The parameter A, is related to 10 Dq in an octahedral field. This value is the maximum for the highest assigned d-d transition. Previous workers (10, 40) have found values for 10 Dq to be over a range of 15,000 cm‘1 1 to 23,000 cm- for the niobium(IV) halides, with the lower 11mit being the iodide and the upper limit the chloride. In this work, the band at 24.4 kK was taken as the highest d-d transition giving rise to a D of 24,400 cm-1. This A is somewhat higher than the reported values, but the extinction coefficient of the band permits this value to be valid. The low intensity band at 12.9 kK in the spectra of the chloride was observed only when the most concentrated solution was studied. It may be due to a transition within the split 2129 manifold, but such a bond is not expected to appear at such a high frequency. The bromide and iodide spectra were very similar, with a doublet appearing in each ca. 13.5 and 16.0 kK. The spectrum of the iodide exhibited an extra band at 20.4 kK which could be attributed to a d-d transition. No evidence was found for this band in the spectrum of the bromide, but it may have been masked by the charge-transfer band at 26.3 kK. This similarity between spectra of DMF solutions of 29 Free Ion Octahedral Field Tetragonal Field Figure 5. (Taken from Reference 40, p. 82). Energy Level Diagram for a Tetragonal Distorted Metal Complex. 30 Table 7 Parameters Derived from Electronic Spectra Complex Assignments A(cm-1) v(kK) 4E0 4E1 4E2 C1 12.9 22.9 24.4 24,400 Br 13.3 15.8 — 15,800 I 13.5 16.1 20.4 16,100 31 NbBr4 and NbI4 will be discussed again when esr data are presented. For the present, the tentative assignments are shown in Table 7 with the two low frequency bands being assigned as (a) 23 + 25 (AE0) 29 g 2 2 (b) 829 + 819(4E1) 2 2 (c) B29 + A]g(AE2) The alternative to the assignments is the possibility that the species in solution is other than NbX4-20MF. This is not considered reasonable for the chloride and bromide, but may be less unreasonable in the case of the iodide, NbI ~80MF. 4 Electron Spin Resonance Spectra Esr studies were performed as described in the experimental section. The experimental esr values are listed in Table 8 with the corrections due to second order effects. These corrections were made using the following equations (41). hv = gBHO (4) Isotropic g [H - mI] :_/(H - mI)2 - 2 (49.50 - 2m 2) H = o o I m 2 (5) g" F 2 2 T H _ [HO - AVInfi] :_ [H0 - 41ml] - AL_(49.50 - 2 mI ) m T 2 (6) 51' [H - A m ] + 1/[H - m )2 - (A 2 + A 2)(24 75 - m 2) H = o .L I —- 0 9L I U .4. ‘ I m 2 32 _e_ oem._ .axw mgspmemagme Eoom coreseom oee._ eoek mom._ mezpmemaeme Eoom ee_om LEON.aemaz ©__ cam mm_ Nem._ ewm._ oew._ .eeou m__ mmm ae_ o_m._ mmm._ oom.~ .axm eoee=_om oee._ ice“ ee_om azom.a_uaz Law ete< rxwm mew mmcwpu_fiam mcwecwqxxe wa.F m—m.— mFm._ mom._ omo.~ me._ Pmm._ mFm.— N—m.— .Leou .axu yak“ .LLou .me mespmcmaeme Eoom corpspom xaNN wesumemgsme Eoom nepom v mzow. an .Lgou .axm xaNN .Leoo 34 Hm is the magnetic field position of the esr line due to the component mI of the nuclear spin I, 0 is the klystron frequency, and , A5,, and AJLare the hyperfine constants. Each Hm was calculated by using the hyperfine constants until agreement was reached between experimental and calculated Hm. The separation of the hyperfine components in gauss is related to energy splitting in cm-1 between adjacent hyperfine levels as follows: 5 A(cm'1) = g x 4.6686 x 10‘ x A(gauss) (8) The spectra are presented in Figures 6 through 13. The chloride complex exhibited the axial symmetry expected for a trans configuration. This was consistent with the interpretation of the far infrared data. The observed 9 and A values, tabulated in Table 8, will be used subsequently to obtain estimates of bonding parameters for this complex. The bromide and iodide comp1exes gave similar solution spectra. The esr parameters were the same within experimental error. In order to determine the possibility of ionization of the complexes in solution, an attempt was made to prepare the hexabromoniobate(IV) in DMF as had been done in acetonitrile (7). A 5:1 tetraethylammonium bromide-niobium tetrabromide was added to DMF. The reaction was run according to methods discussed in the experimental section. After several days of stirring at room temperature, a sample of the solution was examined using the epr method. The 9 and A values were the same. If the octahedral 2-, had been present in solution, some change in species, NbBr6 the epr parameters is expected, given the peff value of ca. 1.23 B M which has been reported for NbBr62' (7). This result seems to rule 35 I 'I I I. I II 5 ' I II (I i . U. I IIIsl‘ I. l l . l u IXII In“..- 1 94 Ill '1'7 I.‘ 1 l 1 1.1 . I." ‘I I9"- I 1111 'IIIII I ’llll‘ Esr Spectrum of NbCl4 20MF in DMF at Room Temperature Figure 6. 36 I‘m—ti H-> Figure 7. Esr Spectrum of NbCl4-20MF in DMF at 77°K. 37 1200—61 1 Figure 8. Esr Spectrum of NbBr4-ZDMF at Room Temperature 38 _—_ “—— Figure 9. Esr Spectrum of NbBr4-20MF in DMF at 77°K. 39 1200 G1 Figure 10. Esr Spectrum of NbI4-8DMF in DMF at Room Temperature 40 1200 G1 Figure 11. Esr Spectrum of NbI4-80MF in DMF at 77°K. 41 12‘0—‘0 GI Figure 12. Esr Spectrum of Solid NbI4-80MF at Room Temperature 42 Figure 13. Esr Spectrum of Solid NbI4-BDMF at 77°K. 43 out equilibria such as NbBr4 + ZDMF + NbBr4-2DMF (9) NbBr 'ZDMF QME-—» NbBr (DMF) 1 + Br“ (10) 4 T 3 3 in which there are moderate to large amounts of cationic species formed by substitution reactions. An alternative formulation of NbBr4-20MF is as either 2’ or other variations on this model. All [NbBr2(DMF)2]2+[NbBr6] should exhibit more than one resonance and in no case was the postulation of more than one niobium containing species necessary to interpret the data. The anomalous behavior of the iodide is still evident in the esr study of the solid. A ten line spectrum of the solid was unexpectedly observed at room temperature and 77°K as opposed to very broad featureless single derivative spectra of the chloride and bromide complexes. In previous work, ten line spectra have been observed only for niobium(IV) diluted into diamagnetic host lattices or in solutions. This phenomenon indicates that the paramagnetic niobium centers are sufficiently separated from each other as if the niobium(IV) were in a diamagnetic host. If the extra ligand molecules, over and above those required for a two-to-one complex, were in a second—coordination sphere, they would have the effect of separating the paramagnetic centers. Were this the case, a possibly more correct formulation of the solid reported here would be NbI4(DMF)2-6DMF. This, however, is in direct conflict with the data found in the far infrared study. No formulation can be made which can rationalize both esr and far infrared data. 44 The lower values obtained for the bromide and iodide at 77°K, may indicate a dependence of on temperature. Fowles (7), in his study of the magnetic properties of the bipyridyl comp1exes, reports “eff is related to 9, one may expect to see some change in as a function of temperature. For the NbBr4-bipy complex, there is a 20% change in “eff over the temperature range 313°K to 93°K. This change in peff observed in this study is ca. 2%. The uncertainty in the calculation of glin frozen spectra due to overlap of glwith g” prevents one from observing this change if axial symmetry is observed and if gJ is high. Hence, one should expect to be lowered as the temperature is lowered. McCarley in his examination of the pyridine complexes of the tetrahalides concluded that the greater the distortion from octahedral symmetry, the closer the magnetic moment will be to the spin only value (4). Fowles (7), however, concludes that other parameters such as A, the distortion parameter, A, the spin-orbit coupling constant, and k, the orbital reduction factor make significant contributions for approaching the spin-only value. In every case in this study, the observed 9 values give ueff only slightly less than spin-only, ca. 1.69, which suggests after Fowles, that either there must be a great distortion from octahedral symmetry, or the complexes exhibit a fair degree of covalent bonding. Kivelson and Neiman (42) have developed equations for Cu(II), a d9 system. If one applies the "hole formalism", these equations may be used for trans complexes of d1 transition metals. The 45 equations are as follows: 9”: 2.0023 - (BA/AE])[a282] (11) 91’: 2.0023 - (2X/AEO)[0262] (12) 2 2 40:2 62 A” = P[-B (4/7 + K) - 2X8 (TE—1 + 3/7 512311 (13) 2 2 _ 2 22 A8 6 AL- P[B (2/7 - K) - if AEO (14) where X is the spin-orbit coupling constant, 748 cm'1 (14), P = 192 X 10'4 (43), and a(dx2_ 2), 8(dxy), and 6(d22) are molecular orbital y coefficients, and 0E0 and AE1 are the energies as assigned earlier. Overlap contributions have been neglected. The spectrum of the chlorine complex was analyzed by using these equations, and the data are presented in Table 9. Table 9 Magnetic and Bonding Parameters for NbCl4-20MF 2 2 g// 91. A//* AJ: 01 8 1.886 1.862 240 116 0.55 0.82 *Hyperfine splittings are given in 10"4 cm-1 From these equations, 82 = 0.82. The size of this coefficient indicates moderate "-bonding by the chlorine atomsin the xy plane 2, 0.55, indicates fairly extensive to the dxy orbital. The value of a covalent sigma bonding in these complexes. In the only other study of metal-ligand bonding parameters (14), a value of 0.62 was obtained for n bonding in the dxy plane, and the coefficient for sigma bonding was 0.45. This study suggests less 0 bonding. By using equation 11, 46 2 one may calculate the ratio-%E—u 62 is restricted to values ranging o 2 from 0.25 to 1.00. In this study, the ratio 7%:— = 1.71 x 10 5 o l 1 confines AE to a range from ca. 1400 cm‘ to 6000 cm- . The tentative assignment of 4E0 = 12.9 kK was incorrect, since this result suggests that the 4E0 transition would be well into the near infrared region. Axial symmetry was not observed for the bromide or the iodide. Far infrared data suggests a tran§_MX4L2 structure for the bromide, and while it was not observed here, esr studies at temperatures lower than 77°K may reveal it. While the esr spectrum of the iodide complex in solution was virtually identical to that of the bromide, this is not unusual given the similar electronic spectra for these complexes in the visible region. The fact remains, however, that far infrared spectra of the iodide exhibited no bands which could be assigned as 0(Nb-I). This result together with the anomalously high ligand-metal ratio precludes any definitive analysis of data obtained for the iodide complex. Unfortunately no esr data have been reported for iodide complexes of niobium(IV). This in fact is the first such report for a bromide complex. Need for further studies of the iodide complexes are indicated, and the results reported here would show that either (a) conductance studies in DMF, (b) anion exchange studies in DMF, or (c) precipation studies with large anions could be useful. 47 SUMMARY AND CONCLUSIONS By direct reaction of anhydrous niobium tetrahalides with a large excess of N,N,dimethylformamide (DMF), products of composition NbX4-20MF (X = Cl, Br) and NbI4'80MF were isolated. Infrared studies of the complexes indicate bonding of the DMF molecules to the metal via the carbonyl oxygen. Far infrared spectra suggest trans configurations for the chloride and bromide complexes. Electronic spectra exhibited two d-d transitions in the visible region for all the complexes. The chloride complex was axially symmetric when studied by the esr method. Using molecular orbital theory of trans D4h complexes, metal-ligand bonding parameters were obtained. The lack of axial symmetry exhibited by the bromide and iodide in the esr study may be due to the temperatures to which the study was confined. BIBLIOGRAPHY 10. ll. 12. 13. 14. 15. 16. 17. 18. 19. 20. 48 BIBLIOGRAPHY L. F. Dahl and D. L. Wampler, J. Amer. Chem. Soc., 81, 315 (1959). L. F. Dahl and D. L. Wampler, Acta. Cryst., 75, 903 (1962). H. Shafer and H. G. Schnering, Angew. Chem., 7g, 833 (1964). R. E. McCarley and B. A. Torp, Inorg. Chem., 2, 540 (1963). M. Allbutt, K. Feenan, and G. W. A. Fowles, J. Less-Common Metals, 6, 299 (1964). D. J. Machin and J. F. Sullivan, J. Less-Common Metals, 19, 405 (1969). G. W. A. Fowles, D. J. Tidmarsh, and R. A. Walton, Inorg. Chem., §, 631 (1969). G. W. A. Fowles and K. F. Gadd, J. Chem. Soc. (A), 2232 (1970). B. N. Figgis, Trans. Faraday Soc., g1, 198 (1961). T. M. Brown and G. S. Newton, Inorg. Chem., g, 1117 (1966). D. Cozzi and S. Vivarelli, Z. Anorg. Allg. Chem., 272, 165 (1955). I. F. Gainullin, N. S. Garif'Yanov, and B. M. 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R. J. H. Clark, Spectrochim. Acta, 27, 955 (1965). J. B. Hamilton, The Synthesis and Characterization of Some Alkyl Sulfide Complexes of Niobium(IV). Unpublished Ph.D. Thesis. Iowa State University of Science and Technology. 1968. R. D. Bereman and C. H. Brubaker, Jr., Inorg. Chem., 9, 2480 (1969). D. Kivelson and R. Neiman, J. Chem. Phys., 99, 149 (1961). B. R. McGarvey, J. Phys. Chem., 77, 51 (1967). APPENDIX APPENDIX Experimental Esr Parameters from Solution Spectra Data in parentheses were obtained at 77°K. All other data were obtained at amb1ent temperature. = GHz HO = Hm = 4H1/2 = Gauss Yo Table 10 Experimental Esr Parameters for NbCl4-20MF in DMF V0 H0 (corrected) Hm AH”2 9.505 3631 2795 60 2950 40 3100 55 3265 50 3440 60 3620 65 3815 50 4015 45 4225 50 4445 60 (9.205) (3487) (2230) (20) (2495) (15) (2745) (10) (4145) (45) (4420) (50) (4720) (60) 50 51 Table 11 Experimental Esr Parameters for NbBr4-20MF in DMF 00 Ho (corrected) Hm AHl/Z 9.518 3547 2730 65 2890 50 3040 60 3195 60 3355 65 3525 80 3710 90 3910 85 4125 85 4310 80 (9.273) (3523) (2603) (30) (2778) (25) (2933) (25) (3133) (20) (3333) (25) (3533) (25) (3733) (30) (3943) (30) (4153) (30) (4373) (30) 1111113111111111111111111111111111111111