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L‘I‘ {II ‘ ..41 l. . III‘H-III MIIQ IIfl‘II-I'I‘IVIII.IW‘:‘II'II III ‘ HIM“ III“ ‘ “ .I .‘L‘IIJ'. II‘I‘II Ib'u.'.‘."IIII ‘WWKV‘IXLI ut-M'II“ THESIS firm-:1 ~ O r .4- I ; , {U7 ‘ g L [1.3.5.2 m 2g 9 mhw :3 g s z 3.34% Unntmty /J This is to certify that the dissertation entitled INTERCALATION 0F CATALYTICALLY ACTIVE METAL COMPLEXES IN MlCA-TYPE SILICATES: RHODIUM HYDROFORMYLATION CATALYSTS presented by FAEZEH FARZAN EH has been accepted towards fulfillment of the requirements for PH.D. degree in CHEMISTRY THOMAS J . P I NNAV IA Major professor Date 8-27-8] MS U is an Affirmative Action/Equal Opportunity Institution 0-12771 fiéflilgkk‘l \ 3"!!!” OVERDUE FINES: 25¢ per day per ital RETURNING LIBRARY MTERIRLS: Place in book return term charge fro. circulation records INTERCALATION OF CATALYTICALLY ACTIVE METAL COMPLEXES IN MICA—TYPE SILICATES: RHODIUM HYDROFORMYLATION CATALYSTS By Faezeh Farzaneh A DISSERTATION Submitted to Michigan State University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Chemistry 1981 ABSTRACT INTERCALATION OF CATALYTICALLY ACTIVE METAL COMPLEXES IN MICA-TYPE SILICATES: RHODIUM HYDROFORMYLATION CATALYSTS By Faezeh Farzaneh + Cationic rhodium complexes such as [Rh(NBD)(PPh3)2] - PF; (g) and [Rh(COD)(PPh J+A3 (A'= PF6, BF“) (ii) are . 3)2 active catalyst precursors for hydroformylation of l- hexene even at room temperature and 1 atm pressure. The rate of hydroformylation in DMF is appreciably faster than in acetone. Solvated sodium ions in the layered silicate hectorite are readily exchanged by complexes I and II; IR and X-ray studies confirm this result. Hydroformylation of l-hexene in the intercalated system shows n-heptanal to 2-methyl hexanal ratio of 3:1, which is similar to the homogeneous results. It was found that these complexes are not well suited for intercalation in layer silicates, because of the reactive intermediate appears to be a neutral monohydride complex RhH(CO)X(PPh (Egg) which is readily 3)2 Faezeh Farzaneh desorbed from the silicate surface during the course of the catalytic reaction. The effects of acid (HClOu) and base (NEt3) on the activity of the homogeneous catalysts in the hydroformylation of l-hexene also support the presence of a neutral monohydride rhodium complex (III). Positively charged analogs of (Til), suitable for inter- calation in layered silicate, are obtained by reaction of the + positively charged ligand Ph2P(CH P Ph2(CH2Ph), abbreviated 2)2 P-P+ with rhodium (T) complexes such as [Rh(diene)Cl]2, Rh(dien)+ where diene = COD, NED and [Rh(CO)Cl]2 in a ratio of P-P+:Rh, 3 2:1. These positively charged catalysts were all active in homogeneous and intercalated systems. In all of the supported catalysts, the rates2 + CO-H2, 0.01M in acetone under hydro- formylation condition (A) after 2 hr; (B) after 16 hrs. . . . . . . . . . . . . . 96 Dissociative (I) and Associative (II) mechanism of hydroformylation reactions (according to G. Wilkinson, et al. 1968). . 102 Mechanism of the hydroformylation with possible isomerization steps (HM = HM(CO)m). . . . . . . . . . . . . . . . . . 108 Possible pathways for hydroformylation and isomerization of l-hexene between the silicate sheets . . . . . . . . . . . . 110 xiii Figure Page 16 31F nmr spectra (A,B) of RhCl- (COD)P-P+BFu 0.01g in acetone (d6) at -30°C, number of accumulated scans, NS = 10000 . . . . . . . . . . . . . 119 17 31F nmr spectrum of RhC1(COD)- P-P+-P-P+ in 0.01M solution of acetone (d6), NS = 10000. . . . . . . . . 122 18 31F nmr spectra of (A) RhCl(COD)- + P-P +P-P++CO-H (1 1) 0 01M in 2 Acetone (d6) at -30°C. (B) RhCl- (000)PPh3 + PPh + CO/H2 (1:1), 3 0.01M in benzene at 25°C. NS = 10000 . . . 125 19 Infrared spectra of (A) 1:1 mixture + + of RhCl(COD)P-P :P-P in acetone under hydroformylation condition (A) crystallized in pentane; (B) recrystallized in CHCl3 131 20 Infrared spectra of 1:1 mixture of RhCl(COD)P-P+:P-P+ + 1-hexene under hydroformylation condition (recrystallized in CHC13) . . . . . . . . 133 21 Infrared spectra (KBr disks) of A, Na-hectorite, and (B) the P-P+- hectorite + RhCOD+ system before hydroformylation. Spectrum C xiv Figure Page is for the P—P+—hectorite + + Rh(COD) system after hydro- formylation . . . . . . . . . . . . . . . 1A0 22 Infrared spectra of [RhC1(CO)2- (P—P+)]BFu. . . . . . . . . . . . . . . . 1A5 XV BFu--Resin COD diphos dt Me NBD NMR NS '12) LIST OF SYMBOLS AND ABBREVIATIONS Tetrafluoroborate anion exchange resin 1,5 cyclooctadiene bis(1,2-dipheny1phosphino)ethane doublet doublet of triplets Ligand (usually phosphine) cationic ligand metal methyl multiplet norbornadiene Nuclear Magnetic Resonance Number of accumulating scans Phosphorus nucleus (usually in a phos- phine) Phosphonium phosphorus nucleus Phenyl group 1-diphenyl phosphino—2-benzy1dipheny1 phosphonium ethane P-P+ tetrafluoroborate P-P+ bromide P-P+ exchanged form of hectorite solvent SIL silica t triplet 6 chemical shift I. INTRODUCTION A. Homogeneous Catalysts The field of homogeneous catalysts includes vast areas of active research ranging from simple acid-base catalysis. to extremely complex metalloenzyme catalysis. It is one of the most rapidly expanding fields of chemistry. Before the last two decades only a few homogeneous catalysts were used on a laboratory or on industrial scale. The past several years, however, have seen the emergence of a variety of novel and useful homogeneous catalyst systems. This rapid enrichment seems to be only the beginning of further growth of this field.1 Examples of some of these developments include rele- vant metal ions which have been found to function as superacids (or superelectrophiles) to accelerate some re-‘ actions to great extent. Redox properties of some transition metal ions (e.g., Cu+ and Cu2+) have been advantageously utilized to catalyze electron transfer reactions. The development of coordination chemistry has greatly helped the understanding of these metal ion catalysts. Soluble metal complexes, especially those of transition metals, are now extensively used in industry to catalyze syntheses of organic compounds. Some of the best known catalyst processes involving organometallic compounds are:2 (a) hydrogenation of olefins in the presence of com- pounds of low valent metals such as rhodium [e.g., RhCl(PPh3)3, Wilkinson's catalyst]; (b) hydroformylation of olefins using a cobalt or rhodium catalyst (oxo process); (0) oxidation of olefins to aldehyde and ketones (Wacker process); (d) polymerization of propylene by using an organo- aluminum titanium catalyst (Ziegler-Natta catalyst) to give stereoregular polymers. (e) cyclopolymerization of acetylenes by using nickel catalysts (Reppe'sor Wilke's catalysts); and (f) olefin isomerization by using nickel catalysts. During a rapid development in the organic chemistry of the transition metals, Fischer and Wilkinson and Ziegler and Natta were doing the research that won them Nobel prizes in chemistry. In fact, their work became a basis for producing many industrial products. In Table 1, ex- amples of major industrial applications of homogeneous catalysis are listed. In addition, conversions of coal to CO is now very important process25 and selective hydrogenation of CO is 26 being investigated actively. Metal clusters are novel homogeneous catalysts for various reactions. For example, ma neaon >> no oompoom omocmmcm5\nooooo Aoaoo oaoaoav oz: + N ea mooz : no momma o : eioaoao+m0mmmmaonoaoao+mo+emmmaouoaoao a m ma muamm >> to oumuoom omocmwcme mooo A movooom \aoqooo no mumpoom pamnoo 02: + NH oumconunamc pamnoo + +mo+mazoouoaozo I Ha mauso+maooa omommo+mo+mmoummo coaoaoaxo ca Hoz+MHonm a Hm+wfioovmoo mooomzo+oo+m0meo . m w m m :m m m m n m : mm+ AOOV 00 mo no A movlmt m+oo+ mUImom a mfimmavaoovmcm o.m MammaVAoovmcm : mmm+onovao omowmmotmm+oo+mmou:0mmo :ofiumamconpmo .mom unmamuwo coauommm m .mumzamuwo msoocoonom wcfi>ao>cH mmoOOLm HmfippmsocH .H manna ‘ III '8' ..|.|'. b -l I I 8f; «Ill em 2030 zommomonzommooz+zoozm+Hom:ozou:om:oHo occlmlusnocwzofiolz.a no opnuommzcmz mm Hose HomzozouzommoHouaomzoaomozoumzo coapmNHLoEomH :Hmmao mm eAmAeaovavaz Zuzvmzovoz+zozm+ strut Hm o~=m .maoam \3flx2au.+m:om:o+ uu/xnv :NmNHoIoHomo . «ma om eaoae+maomfiamom . m Amwmmunmv AI: ““22““ mocofio no :oHuomom an . madam oz . zom+mzo : momma moom+mmoum0mmo ./ \\ 0 ma noaon HHc: mooomzo+mo+oeomzo ea oeooooo AHHvoo mooommo+mo+oazmouc mooo m m ma mez .Ho Lmoo @ 1. NO + m@ zoo .mom ummamumo coauomom .ooscaacoo .H canoe the reduction of CO to methane, methanol, ethylene glycol and others has been reported recently.26’27 Homogeneous catalysts show potential for solving en— vironment problems in the future. Catalytic conversion of poisonous NO and CO gases into nonpoisonous N20 and CO2 has been successfully performed by using [RhClZ(CO)2]' as a homo- geneous catalyst in an aqueous acidic ethanol solution.26 Homogeneous catalysts are also utilized in the fine chemi- cals industry, where delicate control of organic reactions is important. For example, asymetric hydrogenation is cur- rently being used for the production of L-dopa; a drug used to treat Parkinson's disease.29 Micelles, cyclopoly- ethers, and similar macromolecular catalysts3O have been used to accelerate many organic reactions, especially in the syntheses of fine chemicals. The heterogenizing of homogeneous catalystsisscur- rently a very active and relatively new area of research.31 The term heterogenizing refers to the process whereby a homogeneous transition metal complex is immobilized or anchored to an inert polymer or inorganic support.31a In order to appreciate the reasons for the present interest in supported complex catalysts, it is useful to look at the advantages and disadvantages of heterogeneous and homo- geneous catalysts. By looking to Table 2 one can see that homogeneous catalysts suffer from three major problems which are .moLOQ :H mama spoon nonhuman who: Am .zuao sfihfioodm copaedaca Am .mopsampmqeou swag ou oanmpm Am .oanm Ififiw>m ucoucoo Hands on» we open haco .oumppmnnm mfimzawumo oxme moufim o>Huo< AH 50pm manmpmaom zaaomop umzfimumo AH msoocowopopo: .EoHQOLd aco> auaoamHoon 90:60pm IHom no zuHHHnnaom Am can mufi>fiuooaom mumpumnam swam Am .opsumLoQEou mEoHnopa Lommcmpu name on .zuflafinm oEoLuxo on o>HuHmcom Am Ianm> daemon can cacoppooao oaaomm Am uncommoo: coaumpmaom Hence no zunafinmaam>w homo; mamhamumo umzawumo pom uneconm AH >Lm> ou one zufi>fipom swam Aa mnoocoMOEom mommucw>ommfia mowmpcm>c< mmoOOQm mm .mfimzamumo msoocowOLouo: one mzomcmmOEo: mo mmwoucm>UMmaa can nmmmucm>p¢ .m manna sufficient to preclude their use in most industrially im- portant processes. The major disadvantage of homogeneous catalysts is the problem of separating the catalyst from the products at the end of the reaction. The thermal stability of heterogeneous catalysts such as pure metals and metal oxides, is often much higher than that of homo- geneous catalysts. Whereas the range of suitable solvents for a homogeneous catalyst is often limited by the sol- ubility characteristics of the catalyst, this clearly presents no problem for a heterogeneous catalyst. B. Historical Background of Suppprted Metal Complexes The first heterogeneous catalytic process of industrial significance, introduced in about 1875, utilized platinum to oxidize 802 to $03, which was then converted to sulfuric acid by absorption in an aqueous solution of the acid. Other inorganic chemical catalytic processes followed, notably the development by Ostwaldix1about 1903 of the oxidation of ammonia on a platinum gauze to form nitrogen oxides for conversion to nitric acid. Also, the synthesis of ammonia from the elements by the Born-Haber process was initiated in the early 1900's. The conversion of methanol to formaldehyde was introduced in about 1890. Benzene oxidation to maleic anhydride occurred in 1928. The par- tial oxidation of ethylene to ethylene oxide was com- mercialized by Union Carbide in 1937. In the processing of petroleum for fuels, the first catalytic process, catalytic cracking, appeared in about 1937. This first used acid- treated clay, then later a synthetic silica alumina catalyst, and more recently Zeolite catalysts incorporated in a silica- alumina matrix. Reforming, which originally used molyb- denaalumina catalyst to increase the octane number of gaso- line by cyclization of parraffins and dehydrogenation to aromatics, was superseded by reforming process that used a Pt/ alumina catalyst. Catalytic hydrocracking and hydrode— sulfurization and hydrotreating have grown rapidly the past two decades and are now of major importance in petroleum processing. Table 3 lists these and some of the other major industrial reactions which utilize a heterogeneous catalyst. A homogeneous catalyst can be heterogenized in a variety of ways.3u The common method is to attach the catalyst to a solid support by an ionic or covalent bond. Alterna- tively, the metal complex may be physically dispersed within the pore structure of a support, e.g., silica or other suit- able material, by impregnation of a carrier solution of the complex, followed by solvent evaporation. Such evaporations have been termed dry or solid support. The complex may also be dispersed by using a relatively involatile solvent, which remains in the solid after the evaporation steps and which the complex is effectively dispersed. Such sup- ported liquid phase (SLPC) catalyst preparations,35 have 9 Avon: on omam has madame pouncedzm monuov Amsoscfiucoo mo nouns .Louomop hennamv uhoqazmxnonuo no o co om AmnoscHuCOO Lo noumn .pouom Imp mannamv upoaasm m :0 Hz mo .Hz hocmm cofiumcowOLBam OCN Aooo ooxaev Hz oooeoaosm m m goon ooeaev on a can memeo sea: oocoEoto manna Aemopm mo mono tweed :fi .msoscaucoo .omn ooxamv mfiaaomvHmeo ho .moomx oco moato sea: ooooano monoa Aoaacao .ooo ooxaev moma naao can mean cannon no mm+ ooomzo+mmmofimovmommo Acowonozc+ocoumom+aeconomoomfiv m=+mmooommo+zomomfimzov Am:HE&0hop Emoumv m:+oo mmm +omm+mconhm00chn Locuo no :mo Acconzum+ocmncon Hanuov mmoumemzoo+mmmommoo AocofipMpsnv czao+mmcousm Accoaompnnv+mmzo one mucousn Aocmuznv+oamao Acouoz omazpocuo mamas: :ofiumpooo mooncaucoov ooze pouamom new umzfimumo cofiuomom mm.oo:mupoaeH HmfipumsocH mo numzHMumo nzoocomomopom mEom .m manna lO Anon ooxfim onzpfiuasev m0m> ooppooosm goon ooxae ononauaaev mom> occaooosm occaufiocoo wcfi Iozoop um: Loos: .omsmm mad: cm medium mom mcofiu IHUCOO wCHNfiofixo .onsmw opfiz cm medium mom Amoco ocean .oacocnaonv mean so eommx naaomom> cofiumcfixo Anon ooxae oaeocoaoov Amcapozccw oHone Lam+oconcon no ocounnv memzzo mo+mmoo Lo mzzon: Aocfipozccm afloame +Lfim+ocoflmxuo Lo ocoamnuzdmcv cmfioovemoo +mo+mAmmovezooum.H to wzoao AmmooOLn 30mmzpoc£ o>Huoonmv om: oco .oao .omx .mOmaa spa: ooeoeoaa om amm2m+mmm+mz Aooo ooxaev neooosn co Hoods memo: to Hz mamoo+mmm+m=oo Aoouoz omazmonuo mmoHCD coaumpooo mooscaucoov :OHuomom maze Louomom paw pmzamumo .ooscaocoo .m canoe 11 mooaaoon .Aooo oceanv momaa coauaoaoo no Hana: Amoon ooxfim caumomfiomv ouHHooN so And ..w.ov Hope: Anon UHSHMV xfipume on CH no>ofim amasooaoev oufiHooN mcofiuommm pmwNHMmeIoHo< m m o Hv upooosm ucmumamopuofiom no em pmoaosm nufiaocoe Lo pmaaod .pmlpm 90 um , Anon panamv mcofiufimooEoo mofixo OHHHmumEHuHSE LO mmuwflnhHOE kumE XOHQEOO mcoHpHmOQEOO oofixo OHHHMpoEHuHSE Lo Omzo :oHpmNALoEOmH wcfixommoopoz: wcfixommo oauzawpmo o~m+omeo+mom+mzeo Aoeocooo Haca>v mmouzoooomzo +mooomzo+mom+=mmo umzmzxo ousm no no .Hopucoo coHu3HHOQ :a .mconpmoOLozn .00 no coaumofixo ouoHoEoo 0mmm+zozoum=o+mom+mmz+ommo Aoaoo oHHAtoov mooomoumzo LO\ocm Acfimaonomv omomoummo+mo+ommo moozanNom to ma Om: noxoco m=+0mzo+mo+:0m:o Abouoz omfispozuo moods: coaumpodo mooscapnoov :ofiuomom maze Louomom new unmamumo .ooscfiucoo .m manna 12 Amoco ooxae .oaooomaoov m0ma<\ozuaz to memaa\ozuoo sonoEono Hog sea: memaaxmaoso Lmzuo Anon GHSHMV mLouOEOLQ sea: on Aooo ooxaev Hz ooohooosm Anon ocean manganese to noon ocean .oaooooaomv memaa to Monte can: oouoeopq OCNIHso no .mOmpo Spa: pouoEomo OCN mow mfimosucmm no mcofiuomom , Anon ooxfimv gammy owcwnoxoncofi oozunpfiom no ofiom Hmpocfiz Anon ooxaev anao co scam: m Anon mcfi>oe no ooxfim .ofiumnmfiomv cmaa ooaeaoaoo co nHuoa so .omuoa .oa cofipmmfipnmasmooomomz Acmz+maoammo+mom+aomm+emmo ..m.ov H :ofiumcfipoficomxo Amfimmcucmm condonelpocomfimv .0po .mcfimumpma+mm+oo Acoaoocmcooev cmz+ezo+mzm+oo :Om:o+mzm+oo Honooam HhQOLQOmH ou oon>o0LQ ..w.o .cofiumpozz :oHpmNfiLoE>Hom MCHELomoL oauzamumo Aoouoz omfizpozuo mmoacs cofiumpoao msozcaucoov ooze monomom pom umzamumo cofiuomom .ooscaocoo .m canoe 13 .mm monopomom some pouowo< mofim no m0ma< co ooumoaazm ochno .owmum opzumaoQEou nozoa .nCOoom m pom MApon ocean cacoooaonv memso sea: oooosoho ecmoa Anson ooeaoo monaa Aumfinm mmwlpoumzv mm+moo+oo+0mm AmmooOLQ mommov Ommm+mm+mmmm+mom Aoouoz omfizmonuo mamas: coaumpodo unconfiucoov mama pouomom can umzamumo :oauomom .ooscaocoo .m canoe 1A 36 received some attention though this has been limited. Each general method has its advantages and limitations. The ionic or covalent anchoring procedures are preferred in general since the dry or SLP catalysts may be easily desorbed by immersion in solvents or liquid solvents. For use in gas solid reactions, all three methods could in principle be used. Supports which have been applied for the heterogenizing 31a,32a of homogeneous catalysts may be organic or inorganic: Organic supports: polyamino acids acrylic polymers styrene polymers cellulose cross-linked dextrans Inorganic Supports: silica glass metal oxides Zeolite clay 2. Polymers As a Support for Homogeneous Catalysis This field has certainly been the most intensively studied from a fundamental point of view. A great deal 37 as well as DO of work has been carried out by Grubbs et a1. 38 Braca et al.,39 Graziani et al., by Pittman et al., using polystyrene-divinyl-benzene cross-linked polymers. The most common technique involves linking diphenyl phosphine group to a benzene ring of the polymer as indi- cated in Equation (1). 15 ,CCl5 r.LiPPh2 THF, N: @ Ph2 Dark, P. P -RhHCO (‘13)j (l) @ PPh2RhH(CO) (PPh3)2 < Then by simple ligand exchange it is possible to graft the metal complex onto the polymer, e.g., zero valent nickel complexes, bivalent nickel complexes, Wilkinson complex, II ruthenium complexes, RhH(CO)(PPh3)3, Vaska's complex, and so on. Many catalytic reactions have been carried out with these supported complexes. An interesting feature of these supported complexes is related to the possibility of multifunctionality ob- tained by grafting on the same pelymer with two different catalysts capable of catalyzing two different reactions in a two step process. For example, it is possible to cyclooligomerize butadiene on a nicke1(0) complex and then to hydrogenate the cyclic dimers to the saturated hydro- carbons with the Wilkinson catalyst. An important contribution to the field of multifunctional 16 catalysis has been made by Gates et al.“1 who applied to the "Aldox" process a multifunctional catalyst which con- sists of a rhodium complex and amine groups linked to poly- styrene-divinyl benzene matrix. This industrially important . process is a multistep synthesis involving homogeneous catalysis. Propylene is hydroformylated to give butyr- aldehydes in the presence of a CO or Rh catalyst, the al- dehydes undergo base catalyzed aldol condensation and catalytic hydrogenation of the condensation products yield 2-ethyl hexanal, a major plasticizer alcohol: CH CH tH3CH0 CH Rh 3“ 4 -H20 : 3 CH3-CH=CH2-———-—<: ‘:>»____4> CH3-CH—CH=C-CHO CO+ Amine H2 CH3—0H20H20H0 CH2 CH 3 I H2 Rh 9H3 CH -CH-CH -CH-CHO 3 2 l 9H2 CH3 (2) A representative structural element of the multifunc- tional catalyst is given on Figure l. The multifunctional catalyst beads were compared to a combination of two kinds of catalyst beads, one containing Rh complexes and the other containing only amine groups. The multifunctional catalyst was superior, giving rate constants which were 17 CH—CH 2—CH‘—' CH"2 —CH— CH 2-CH 9 9 9 H2 CH2 Cl ©-P-@ @-r|*@ Cl-Rh-CO H C H P \/ 2 5 CH C1 CH2 CH2 92 9 CH—CHZ—CH—CHz—CH—CHz— H Figure 1. A representative structural element of the multifunctional catalyst. (Examples of olymer supported catalyst applications are provided in able A.) 18 u x e mimaaavooacm enema aaoav , meaa-saoa o: sodomH>ELom0pozz m m x m amm coacocowotoam Aoov Hose: e naauaaoav IN x . me coaoocomosoaz x AmcaavfloooaH: emnaauafioav KI x Aommv coaoocowoeoam mfimzaavaonmu AmcaauaHoav mcaanaaoa mama mammz Aonozv AooHEmHm z: Amocmxaaom mHom m.m.a u x .o: .Ho u m Anvwm cofiumcowOLpzz .xmaeqolmaom nonmaom .umm coauo< oauzamumo meQEoo poupooasm oomOQOpm Amvumoaqsm .mummamumo pontooasm Leahaom no cofiumOfiada< .= manna 19 .mmezHoaoo AnzolmcmpzumvzHoa :H E u zHomm ( . Hosmxamcaa m nwm :oHumNHLmEowHHOOHozo m x m . zHom nmmlmHom Hoovaz a can . omm coanouacoEomaHooHoao onova2m¢mzaaaHoav WenonaHoa I x mm coaoonahosao soocan x eAmnaavoa amcaa AHoaV mnaauaHoa Hm coaooHanoaoam mHouam: .mzoaHoa moEmeo aHoa om coacoHanonoam mHHoonovnmL .moZZNmouaHoa mo22m=o aHoa ApmuwcowOLozn a: :oHumNHpoemHom m zHHmHuLwdv mHom Hoom__ . memoumm .:u m .:u mu m H m H m m N m N H: .coocoo xooH< Honm 4 can :p/aHoa can :07/aHoa a m U I mmHmz :0 m Hmz maaooveoo w: :oHumHzEpouopom: Lo NHHoovszm. zAHV zHom HocHoszQHch>vaom . o : ImmOpo A: coaoaHaeeoeoeoam MHocmmozznmmouaHoa Home am y ozz mouaHoa .mom 20Hu0< owuhHmumo onQeoo omuhoaonm pomoqopm upooasm .ooscaocoo .: oHooe 2O five-fold greater for hydroformylation, 15 fold greater for condensation and 30-fold greater for hydrogenation. 3. Inorganic Support for Homogeneous Catalysts Inorganic supports suitable for use in the attachment of metal complexes may be classified into the following groups: 1. High surface area oxides (mainly 8102, A1203, aluminasilicate type). 2. Layered structures (mica-type silicates (clay), tantalum disulfide and related sulfides, graphite). 3. Cage-type lattices (zeolites). A. Advantages of Inorganic Oxide Over Polymer as u rt Unlike polymers, which are flexible and can be swelled to varying degrees depending on solvent, temperature and pressure, metal oxides have rigid structures. Also, metal oxides are less susceptible than organic polymers to chemi- cal or thermal degradation. A stable structurally rigid support limits the number of surface attached liganding groups capable of binding to the metal complex. Thus, it should be easier to control the degree of coordination un- saturation of the metal center on metal oxide surface, than in the pores of a flexible polymer matrix. Structural r 21 rigidity is also desirable in large scale applications, be- cause the size and porosity of the catalyzed remains constant through the catalytic reaction. Although polymers can be stiffened by crosslinking, they become increasingly brittle with increasing crosslinking and attrition of the polymer particles becomes a particle problem.“b 5. Inorganic Oxides as a Support Much work53 has been carried out by British Petrol- eum which has been intensively studying a wide range of catalytic reactions. The most interesting aspect of the work is related to development of new methods for grafting many homogeneous catalysts on silica. These meth- ods seem to be general.53 The first method (A) involves reaction of a coviling reagent, e.g., (Et-O)3Si-(CH2)n-PPh2, with the silanol groups present on silica to obtain a grafted phosphine. It is then possible by ligand exchange to graft any kind of precursor complex. The method (B) involves first form- ing a metal complex with the (EtO)3-Si(CH2)n-PPh2 coupling agent or ligand. It is then possible to control the num- ber of silane ligands before grafting the complex to the support (Figure 2). Similar functionalization procedures have been adapted by Moreto et a1. and Kochloeff et a1. (silica) and by Capka and Hetflejs (silica, y-alumina, A glass and molecular sieve zeolite).3 c 22 .moHHHm co mHmszumo mzoocowoeoz mo wCHummLo .m opszm meQEoo mzoocowOLouon onQEoo mzoocowoeo: Aoovoooocmmnaamammovuamno + AoovAoooovnmmhaomammovnamumAOomv + mo onQEOO onquo mzoocomoEo: Lompsoopm mcmHHm pcmeH HooviflomoovcmumcoamfimzovnamumAOcmv + cvoooovcm + madamflmmovammAOva m oozemz pompsoopm mequo msoocowopouon onQEoo mOHHHm ocmmHH 00AomowvzmlmnmmlmAmzovalo + NAOOVHomomvnm + mzmmmzom:OIHmio MQHHHm ocmmHH ocmHHm ocmeH oommpzm mOHHHm mamamzomzonamuo + mcaammo-mmoammH0omv + no < oomemz 23 III'AIIIIII' I I‘I. I. mm a coaeocomoaoam AonlmHmzovmcaavaosm om.oo a coaoacomoaoam mHaHmueAmmovezoomcaavaote. am a coaeonasoEomaHo mAquumAmmovmcaEVHooosz am a coaoonatoeomaHo mAaHmumAmzovmsamvaoaz mm.em a coaooHaesoeoooam Anammfimzovmcaavxmfioooovoo mm.em m. coaonHHEtoaoooaz AnHmuezmovaoovmoo em a coaooaacooaoo onumAmzovmcaa\onoonv om coaooHHnotoam a am.mm a coaonHacootoo HonmAmmovmnaavaooo mm a coacoHanocoam aHmmAmmovmo22\oHooam: am < coacoaahoeonH. onumH«movmcamerocm\:MHooa mm a connoHHnotoam nHmmHmzovmnaa\mHonm mm m .eotoaz mAnHmumAmmovumnaaxoovmnm mm m.< .moaoa: a .eoeoam mAnHmumAmmovmcaav Hone em m concocomonoam mAnHmnemmov mHoHe em m coaoocomohoam Haemuemmov «Hoaeoo :o:amm .eom bongo: :oHpo< oHqumumo onQEoo coupooosm comedopm whoaqsm .HmoHHHmV uaoaazm oHcmwhocH co mumszumo mzoocowoeo: no wcHummpw .m oHnme 29 Another method of catalyst immobilization on inorganic supports involves the direct reaction of an organometallic complex with hydroxyl groups on the surface of the support. This method of immobilization is significantly different from the preceding one which uses a coupling agent, since the method of grafting is such that the support acts as a ligand directly bonded to the transition metal. In many cases the formation of 814144 bond or Al-O—M bond are T t involved. It does not seem that in this case, the molecu- lar nature of the catalyst is kept at least in the sense of a homogeneous complex, but the resulting catalyst may ex- hibit very high activity and selectivity compared with the homogeneous counterpart. Very intense research in this field 310’61 and to Yermakov is due to Ballard and coworkers and coworkers.62 The general method involves the reaction of an organometallic with the surface groups of alumina or silica (Figure 3, Table 6). Another alternative in immobilization has been developed by Yermakov63 and closely resembles the usual techniques of heterogeneous catalysis synthesis. After grafting the organometallics to the surface, drastic reducing treatments under hydrogen or oxidizing treatments under oxygen will lead to a wide range of oxidation states. The advantage of using these organometallics as starting materials is the high degree of dispersion obtained on the surface. 25 \ 331—0}: ‘81-0 / -/ \ /\ O + Zr( -allyl)u-——H>O\ /}r + 2 ,’ >81-0H ,si—o / I \ ‘\Si-O \Si-O OBu . / \ i‘ ‘/ \' ” + 2/’\~ 0 Zri + 2BuOH—9 0 Zr 2. / \ / 5 Si-O/ \OBu /Si-O / l I “\Si-OH \/S‘i-O\ .7! d/ + Mo( -a11yl)u.4, OK /Moj + 249\\ \ i-O ‘J /si-0H /s' Figure 3. Direct interaction of organometallic compounds with silica surface. 26 so coaomnatoeHo MHocm momaaum0am so :OHumNHpoeHa mHosm momH< :oHumcoHBAOQopomHa :AHHHHmuev 3 :oHpmcoHuLOQOLomHQ zfiHzHHmnev mo: on :oHpmcoHupooopamHQ :HHHHHmlev oz mONH< to mon AH .hm .Ho u an COHumNHLmezHom mxAmImOIev Hz OHM :OHumNHLoEHHom :AHHHHmuev no mONH-O)nM M=Zr, Cr olefin polymeriza- . tion hydrogenation Hz <:>—0H + M0 M=Ni, Pd, Pt supported metal M=Mo oxidation catalyst. 2 O @"erM Figure A. General types of possible surface reactions. (Adapted from Reference 3Ae). As has been mentioned, the methods most studied for complexes immobilization is covalent attachment or ionic attachment of transition metal complexes to support via functional group ligands. Electrostatic binding of cationic metal complexes to crystalline inorganic matrices represents 28 a promising approach to the problem of supported homogeneous catalysts. Unlike covalent methods of attachment, electro- static binding does not require the Support to function as a ligand. The inorganic matrices best studied for the electro- static immobilization of metal complexes are the crystalline two-dimentional layered silicates related to the micas (e.g., montmormillonite or hectorite and the three-dimen- sional silicates or zeolites. Related classes of compounds 65 and graphite66 such as layered transition metal sulfides are also capable of intercalating metals and metal complexes of catalytic interest. Although layered silicates and zeo- lites have been extensively investigated as protic hetero- geneous catalysts, studies aimed at their use as supports for metal complex catalysts are in the first stages of development. Three limitations to the use of an anionic inorganic framework as supports for homogeneous complexes can be anticipated: 1. The metal complex must be cationic. ii. A solution-like environment in the intracrystal regions may be necessary to realize catalytic activity. iii. The reaction may be diffusion controlled. Although a large number of homogeneous metal complexes 29 Table 7. Physisorption and Ion Exchange Reactions in Zeolites and Layered Silicates. Silicate Exchange Cation Catalytic Ref. Application Zeolite + (Na /y-Zeolite) Rh(NH3)g+ Hydroformylation 67 Zeolite + (Na+/y-Zeolite) Cu Cyclodimerization 68 + Co2 Oxidation 69 Layered Silicate +. Na -hectorite Rh2(0AC)fi_x, PPh hydrogenation 70 3 + Rh(diene)L2 hydrogenation 71 _ L=PPh3, diphos 4. [Rh(diene)(diop)] asymetric hydro- genation 72 30 of interest are suitable for binding in layered or three- dimensional studies because they are electrically neutral or become neutral during the reaction and readily desorb from the supports. However in zeolites sometimes desorp- tion can be prevented because of the limited pore size.67 Research Objectives: to synthesize a positively charged metal complex catalyst suitable for intercalation in layered silicate and to examine the properties of the intercalated complex for catalytic hydroformylation. To provide the necessary background for the research, the structures of layered silicates will be reviewed and the properties of homogeneous hydroformylation catalysts will be surveyed. 6. Structural Features of Layered Silicates73 The term clay as used in soil science and geology refers to any inorganic material with a particle size <2u. How- ever, the term "clay" which has been used in this thesis, refers to layered-lattice silicate minerals. In all the groups of mineral shown in Table (8) a common structural feature is a hexagonal sheet of linked SiOu tetrahedra. The vertices of the tetrahedra in each sheet point is one way except for polygriskites and members of the serpentine group. If such a sheet is envisaged as being formed by condensation-polymerization of Si(OH)u units, it will be seen that all the vertices are hydroxyl groups and that the composition of the sheet is Si203(OH)2. The hydroxyl 31 N moH on OOH» o as .NA:OVAOHOeAam.HavaH<.oa.mzvm\eAmz.oov oasesoe Hotocoo mmmuHHsoHELo> «AmovAoHOeAH<.HmeHH<.wzvoo anamooaom cs: on emm mAzoVHOHONHmm Hav mHafleHoa.mzv oaooaooHno Nom NH:OVAOHONHmNHms deLocHz oEom .m oHnmE 32 A.nm> mocmpmumm E099 pmuamp HooHdmu < .ucomopd mCOHumo can :qu ocm zquHezn o>HumHop :qu zpm> mucoucoo poum305b .HmpoCHE zmHo no N OOH too 005 cm poncho wcHucomoLdop .mm.o usonm mH omH:ELom o>oom map CH x ouHuooEm HmoHdzu m :H .ucomopd mcoHumo oHnmowcmnoxo mo mucmHm>Hnoo mo Lopez: on» mH x on com .wz new no .mz we soon :oHamo oHomowcmnoxo so no ucon>Hzoo moo monocoo So I! cm:2.mfimo.avHoHOeHmeHHa.Hovmxxgoo.ozv QUHLOquQSeHOSHm o~m2.mA:ovAOHoeamvaHa.anvm\xfioo.mozv ooasoooo: owes.mH:oVHoHonuavamxH ./"~’ + (3) The reaction is homogeneously catalyzed by a number of transition metal carbonyl complexes. Cobalt is the most 39 widely used catalytic element for this reaction. Rhodium catalysts increase both the reaction rate and selectivity of the process, but it is very expensive. . Commercial use of the hydroformylation reaction is on a large scale. The ultimate commercial products are al- cohols, either l-butanol or 2-ethylhexanol, which are formed by the hydrogenation of the aldehyde, 2¢ethylhexanol is used as a plasticizer82 component. The oxo products also can be used as solvents, lubricants, detergents and so on.83. Despite the highly developed oxo technology based on HCo(CO)u or the catalytic species, there has been no lack of attempts to improve the total yield or the selectivity of the reaction. In addition, efforts have been directed at increasing the activity of the catalysts via variation or modification.Therefore, the oxo reaction has been the subject of a very large number of patents, scientific papers and review articles.8u The complexes summarized in Table 9 have been inten- sively studied as hydroformylation catalyst precursors. Among these metals, rhodium and its derivatives were found more active and at least as selective as cobalt (as carbonyl form), whereas ruthenium and iridium appeared fairly active but less selective. Recently hydridic plat- 85 inum complexes were found to have catalytic activity comparable to that of cobalt. Other metals like iron, osmium, nickel, palladium, and their derivatives tested to AO Table 9. Hydroformylation Catalysts and Their Variants.(8u) Catalyst Precursor Modified By Mn(CO)m M Co, Rh, Fe, Ru, Ir, Os, Pd, etc. e.g., C02(CO)8, Rhu(CO)12, Ru3(co)l2 OS3(CO)IZ, Iru(CO)l2 Hal M(CO)mLn M Co, Rh, Fe, Ru, Ir, Os Hal = Cl, Br L = PR3, P(OR)3, AsR3, etc. e.g., 01Rh(co)(PPh3)2 date showed slight to very slight activity. For a number of other metals like copper, chromium, and tungsten the catalytic activity have not been investigated sufficiently. Reactivities of various metal carbonyls as oxo products relative to cobalt are shown below. Rh > Co > Ru > Mn > Fe > Cr, Mo, W, Ni A -2 -A -6 103-10 1 10 10 10 O Mn(CO)m type complexes are precursor catalysts, but by the addition of CO and H2, a monohydride carbonyl complex is formed according to Equation (A) which is the active species A1 for hydroformylation reactions. Mn(CO)m + H2 + CO_)HMn,(CO)m, (u) 86 Rhu(CO)12t-,Rh6(CO)l6 EA) // HRh(CO)u Active intermediate (species) The problem with this type of catalyst is that the selec- tivity is low, which is not favorable for industrial usage. The normal—to-isomer ratio can be dramatically increased by replacing the CO ligand with organic electron donors such as amines (NR3), phosphines (PR3), phosphites (P(OR)3), arsenes (AsR3), etc.,which is called "ligand modification", and has led to industrially relevant development in the catalyst recycle as well asixlthe oxo process itself.87 HM(CO)m + L2HM(co)m_lL + 00 (6) HM(CO)m_lL + L¢m(co)m_2L2 + 00 (7) HM(CO)m_2L + L2HM(CO)m_3L3 + CO (8) A2 The ligand modification of HCo(CO)u was used by Reppe et al for the first time in 19A1 for stabilizing catalysts. After the basic research conducted by Slaugh, Mulineaus and Wilkinson (1966), ligand modified catalysts have been used for industrial applications. Ligand modification has a dras- tic effect on oxo catalysts where the central atom is Co or Rh. By replacing some of the CO ligands with other donors such as PR3 the selectivity, reactivity and stability of reactions can be changed. For example, the stability of metal hydride carbonyls of Co or Rh modified with electron donors ligands PR3 have been increased. However, the catalyst activity drops when the selec- tivity increases. Also, the ligand modified oxo catalysts are more active in hydroformylation than their unmodified counterparts.88 Selectivity usually has been increased by ligand modification. Recently mixed metals have been used for hydroformyla- tion reactions89 , i.e., Co-Rh or Co—Pt, Co-Fe. Mixed catalysts are said to exhibit particular effects besides an increase in activity. However, the homogeneous catalyzed hydroformylation with a metal carbonyl of the type HM(CO)mLn requires a step after the actual oxo stage to separate, recover and re- process the catalyst. Heterogenized hydroformylation catalysts can be prepared as follows: A3 A. Polymerization or Copolymerization of suitable monomers; B. Functionalization of formed supports (organic and inorganic); C. Precipitation of metals on supports; D. Impregnation method such as SLPC. Method A is rarely used for heterogenized oxo catalysis. The most well-known example is ICI procedure for the polymerization of suitably substituted bis(dialkyl-styrene phosphine) metal halides.90 There is a number of standard methods for the function— alization of polymers, silica gels, zeolites or other supports according to method B. This method has been explained before in Section (I-B2). Method 0 includes systems in which the complex is chemi- sorbed to the supports. The SLPC technique in which the oxo catalysts, dissolved in high boiling solvents (in some cases the ligands themselves are used as solvent), are deposited in the pores of suitable supports where they are made available to the gaseous reactants (alkene and CO + H2) and the use of Co-Al silicates are examples of Method D. The SLPC Technique is very useful in the gas phase hydroformylation reaction which is the subject of re- cent studies of hydroformylation reactions. At the moment, oxo active clusters-polynuclear transition metal carbonyls with M-M bonds are also subject of intensive research. This AA intensification of the research of the transition metal com- plex is also exploited in hydroformylations. The results are less surprising than the fact that the clusters (C03- (CO)9[u3-(C6H5)], and Col,(CO)8(u2-CO)2-(uu-P6H5)2 can be recovered unchanged after the reaction. \ co- “0 o-c- oe—\ / / /Co COO / \ // o-c I‘Sc-o 0'0 p c-o C l I H 0 Q: Figure 6. Cobalt clusters for hydroformylation. Pittman et al.91 have also studied the hydroformylation re- action with cobalt clusters and postulated a mechanism based on the Heck and Breslow mechanism. Table 10 provides some examples of these four methods. The objective of the present study was to examine the properties of intercalated hydroformylation catalysts. “5 om.o.omm NHHooovHonmL acaconoco HaHHam om.o.omm NnHoNAoovnmu oCHnomozo HzHHHm omm mHooVAoooovcm anaconoco HaHHHm ooHHam omm :Hoovsmm deaconoco HaHHHm ooHHHm m omm efioovcmm ocazonozo HaHHam mo.omm mfimcaaVAooVHocm em.em mHonoVHoomL anaconono HaHHam noaHam. noaaam mm mgoovgmcaavoo we mnaaoozm: omm mcaaoofiomomvcm deaconoga m>ouocoaaenaHoa mm Amcoavaooo ocaconoza m>o:ocosaonsHoa mm Amcaavoomfioovcz seasonoca m>onocoaaenaHoa mm mfimnaavmgoovoa ocacnnoca m>ouocosaonaHoa mm mamnaaveHoovoz ocHzonoca m>ouocosannaHoa AsoeaHoaV m cm :Hoovooz HocHanoza ozonzumqucH>HovlaHom < .mom umzHopmo Lonesomnm ucow< wcchHH upoaosm oonuoz .nonaHoooo oouaaaoossH coax coaeoHaesooosoa: .OH oHooe A6 mamcaavoo HAHHone cm (' |.| Hit: 8!, I‘ilnl it'll. lazuli. . Ill [[ i t .l't' I :oH osoaccooe Odom notooosm tonne memHa almanavoloovnoo HooonmNHmamo mechaenaHoa ocean: mm eaoovoo: -o- ocaHooN mm mAmnaavooHHAHHouevcm momaa em mhmnaoVAoovmcm conconona HAHHam ooHHam m .mom umszumo nompsoonm pcow< wcchHH uncoonm bosom: ‘I III .ooscaocoo .OH canoe A7 Most hydroformylation catalysts are neutral and are not suit- able for use in layered silicates. In fact, to achieve catalyst immobilization in layered silicate, the catalyst should be positively charged. Cationic complexes of type Rh(diene)- (PPh3): were selected for hydroformylation in homogeneous and intercalated systems. In 1978, Oro et al.105 reported these type complexes are active under mild conditions at temperature and pressure. As will be shown later, however, the catalytically active species derived from Rh(diene)- (PPh3)2+ precursors are electrically neutral and readily desorb from the silicate surfaces. Nevertheless, complexes suitable for the formation of intercalation catalysts were obtained by replacement of the neutral phosphine ligands in RhCl(diene)PPh3 and Rh(diene)(PPh catalyst precursors + 3)2 with a positively charged ligand. There are a few examples of positively charged phosphine ligands in the literature, Table 11 lists some of those ligands. A8 Table 11. Complexes Containing Positively Charged Ligands. + Complex L Ref. Mx (L+) Ph PCH CH + CH 6 3 2 2+ 2PPh2 2Ph 10 2+ 2+ M = C0 or Ni Ph2PCH2PPh2CH2Ph x = 01, Br, I c B (L+) Ph PCH CH PPh CH Ph 10 0 r3 2 2 2 2 2 7 + MX L CH 3 $/' 2\. CH3 Ph 0: PPh 108 + M = Co2 or Ni2+ 2 “0H2”\ 0H2” 2 + [Au(L )013JC1 " (108)b + . ,n ' [Pd(L )2012](Clou)2 (108)b + ' , [W(CO)5L JBFu [P(OCH2 )3 PCH3 J 109 [Ph 2P(CH2)2PPh2CH2Ph] 110 + [W(CO)5L ]I [cis-PhaPCH= CHPPhZ-CH3]: 111 [TransPhZPCH=CHPPh2-CH31+ 111 + [M(CO)5L JBFu [(CH3)2PCH2 CH 2P(CH 3)3]+ 112 [Ph 2PCH2PPh2CH3 1+ 112 M = Cr, MO, W [Ph2P(CH2 )2PPh2CH3 1+ 112 II. EXPERIMENTAL A. Materials Sodium Hectorite (Bl-26) was obtained from the Baroid Division of National Lead Co. in the Pre-centrifuged and spray dried from the idealized unit cell formula is NaO.A2[M85,A2LiO.68A10.O2](818.00)O20(OH’F)A79d and the experimentally determined cation exchange capacity is 73 meq/lOOg.7ub ‘Sodium Montmorillonite (Upton, Wyoming) was obtained from the Source Clay Minerals Depository. The trichlororhodium(III) hydrate used in this study was either obtained as a gift from Monsanto, Co., or pur- chased from Engelhard Industries, Inc. The di-u-chlorotetra- carbonyldirhodium(I) was obtained from Sterm Chemicals Incorporated. Triphenylphosphine, benzylbromide, 1,5- cyclooctadine were purchased from Aldrich Chemical Com- pany, while sodium tetrafluoroborate and potassium hexa- fluorophosphate were purchased from Alfa Products-Ventron. Dowex (AG2-X8) anion (Cl-) exchange resin, 50-100 mesh, was a gift from the Dow Chemical Company. Bis(l,2— diphenylphCSphino) ethane was obtained from PCR, Inc. Sodium tetraphenylborate and silver tetrafluoroborate were purchased from the Alderich Chemical Company. Sodium per- chlorate and activated alumina were obtained from A9 50 Matheson, Colman and Bell. 70% Perchloric acid was purchased from the Allied Chemical Company. l-Hexene was purchased from Pfaltz and Bauer, Incorporated. It was purified by distillation over alumina under argon or nitrogen atmos- phere. All solvents were reagent grade, except that spectro- grade solvents were used for the hydroformylation re- actions and NMR studies. The solvents were degassed prior to use by standard pump-flush or freeze-pump-thaw tech- niques. Benzene and toluene were dried over lithium- aluminum hydride for at least 2A hours and freshly dis- tilled before use. B. Physical Methods 1. Infrared Spectra Most of the infrared spectra were recorded by employ- ing a Perkin-Elmer Model A57 grating spectrophotometer. The samples were prepared by mulling in fluorolube (Hooker Chemical Company) or mineral oil (Nujol), and then placing the mull sample between CSI plates. Also, some IR samples were prepared as solids in KBr disks. A wire mesh screen served as an attenuator in the reference beam of the spectrometer. Mulls of oxygen sensitive samples were pre- pared in a nitrogen filled glove box immediately before measurement. Spectra of hectorite and rhodium exchanged 51 hectorite were obtained by use of a Perkin-Elmer Model 225 IR spectrophotometer. Oriented film samples were pre- pared by evaporating 1% aqueous slurries of hectorite mineral at room temperature. 2. X-Ray Diffraction Studies A Phillips X-ray diffractometer with Ni-filtered CuK(a) radiation was utilized to determine the 001 basal spacing of samples of the layered silicate before and after ex- changed with the desired cationic complex. The basal spacings for the mineral in the dry form were determined by spreading thin films on microscope slides and monitor- ing the diffraction through 2° to 1A° of 28. The X-ray diffraction of mineral wetted with acetone was obtained by replacing the microscope slide with a slab of white, porous, fire brick, and soaking the firebrick in acetone. The peak positions in degrees of 28 were converted to d- spacings with a standard chart. 3. Proton NMR Studies Proton nuclear magnetic resonance (1H NMR) spectra were obtained by use of a Varian T-60 (60 MHz) and a Bruker WHM 250 MHz. The spectra provided a check on the purity and identity of solvents and compounds. Chemical shifts were usually measured relative to tetramethyl silane as an 52 internal standard. A. Phosohorus-Bl NMR Studies Fourier transform, proton decoupled, phosphorus-31 NMR spectra of cationic rhodium complexes were recorded on a Bruker HFX-lO Spectrometer modified for multinuclear 113 and measurements as described by Traficante 32 21., interfaced to a Nicolet 1083 computer with 12K of memory, a Diablo Disc memory unit, and Nicolet 293 I/O Controller. During these measurements an external lock mode was em- ployed, wherein the spectrometer maintained a constant fluorine-l9 lock on a sample of hexafluorobenzene con— tained in a microprobe assembly externally adjacent to the Dewar assembly of the main sample probe. Chemical shifts, relative to 85% phosphoric acid as an external reference, were calcdated by taking the irradiation frequency to be 36.A3 MHz. Spectra were obtained at approximately 36.AA MHz. The second part of our studies on rhodium complexes with positively charged ligands were carried out on a Bruker WH-l80 spectrometer interfaced to a Nicolet 1180 computer with 16K of memory. Spectra were obtained at approximately53.59 MHz. Samples were prepared by mixing solutions of the desired compounds in 10 mm diameter NMR tubes and sealing them with a few turns of black elec- trical tape. Spectra obtained under hydroformylation conditions, were obtained by preparing the samples in a glove box, in a 10 mm tube equipped with two side arms 53 fitted with a female lA/35 pyrex joint. Then the tube was attached to the hydroformylation line and the CO/H2 mixture was added to the solution prior to conducting the nmr experiment. The sample tube was not spun in the probe in this case. 5. Gas Chromatography Gas phase chromatography of liquid samples were re- corded by employing a Varian Associates Model 90P single column chromatograph with thermal conductivity detector. The output of the detector was recorded with a sargent model SR recorder. The hydroformylation products were separated on 6 ft x 3/16 inch column filled with 20% 8,8'oxidipropionitrile on 80/100 mesh chromosorb W. For the separation solvent, l-alkene and 2—alkenes, a 10 ft x 1/8 in 10% UCW-98 (Hewlett-Packard) on 80/100 chromosorb-W (Hewlett-Packard) column was used. The products were identified by GLC comparison with known standards. Also, GC-Mass spectroscopy was used in the identification of products. The percentage of products was determined by integration of the chromatographic peaks. Integrations were carried out by employing the "cutting and weighing" method. 6. Elemental Analysis and Melting Points All chemical analyses were performed by Galbraith laboratories, Inc., Knoxville, Tenn. 51.4 Melting points were determined on a Thomas-Hoover Model 6A06-H capillary melting point apparatus. C. Synthesis All the synthesis were carried out under an inert atmosphere, either in a nitrogen-filled dry box or on vacuum line. 1. [RhCl(COD)J2 Di-u-chlorobis(1,5-cyclooctadiene)dirhodium(l) was prepared by the procedure of Chatt and Venanzi.llu From the reaction of RhCl3-3H20 and COD in refluxing ethanol. The resulting orange crystals were recrystallized from glacial acetic acid. The compound melts at 256°C and de- composes above 258°C with effervescence. 1H NMR (CDC13) A.2(d), 2.A5(m), 1.72(d). Melting point and proton NMR data were in good agreement with literature values.115 2. [Rh(NBD)Cll2 Di-u-chloro(norbornadiene)dirhodium was prepared from RhCl3, 3H2O and NBD in aqueous ethanol as known literature procedure. The crystalline complex darkened at 220°C 1 and decomposed above 2A0°C H NMR (CDCl3), 3.9t, 3.8(m), l.16(t). The NMR and melting point was agreed with literature values.116 55 3. [Rh(COD)(PPh3l2]PF5, [Rh(COD)(PPh3)21BF“ The hexafluorophosphate and tetraphenylborate salts of (l,5-cyclooctadiene)bis(triphenylphosphine)rhodium(I), were prepared according to the method of Schrock and Os- 117 born by the reaction of [RhC1(COD)]2 and PPh in the 3 presence 0f KPF6 or NaB:oo Anny uco>Hom pmszumo cam IHaroozIN A asap a coaesoasonao oosoota m.mnomn:oonm ummHmumo mm 0% +NA chNVHocmHovcm anz ocoxozl H mo :oHumHzenomonoz: nsoocomoeo: .zH oHnt 81 .Hum.N u MHoumcmLB .Huoom u em “ ocogomuH mOoOOH :"oo moCOpoom :H mo.H n monoxomIHum .QEDB :oHuomom mHmo cow u onnwmono Hmuoe mHuH N o O.m NH mm OO OOH H w Hey m.m mH Om Om OOH H m HOV m.m new Hm mm OOH . H O Hmv o\c ocmxomlN Hmcmxo: HmcmudomI: .>:oo Anny oooo< 22m :Haneozum H oeHe mead HHS :oHosoHsOnHo nosoooa noHoz m.nompsoonm uthmumo mm mmmmNHmSNNVAooovnmu nuHs ocoxole no :oHumHzELomonozm anomCDNOEo: .mH mHome 82 catalyst precursors. In fact, the lower ratio of n/b at 100°C must be associated with the dissociation of triphenyl- phosphine under such conditions. In 1978, Oro 33 21 reported that [Rh(COD)(APh3)2]ClOu (A = N, P, As, Sb, Bi) are active catalyst precursors for hydroformylation reactions.105 He also mentioned that the IR spectra of the catalytic solu-. tions resulting from experiments with (PPh3) and (SbPh3) show absorptions which clearly indicate the presence of these coordinated CEO ligands along with bands due to non-co- ordinated C10“- (anion).122 The bands assignable to V (CEO) are located in the 2100-1950 cm.1 region. It was claimed that the CEO bands are characteristic for cationic 117 He proposed that the active carbonylated species. species should be cationic. Further studies on homogeneous systems are listed in Table 16. According to this table, it is especially note- worthy that the addition of triethylamine (NEt3) to the reaction mixture at 25°C increases the reaction rate without influencing the aldehyde distribution (runs8,9), whereas HClOu in DMF as solvent greatly depresses the reaction (run 11). On the other hand, the addition of two moles of NEt3 to the solution containing one mole of H010“ restores the catalytic activity. The addition of HClOu to the complex in acetone solution, caused a dark red color to develop and no hydroformylation product was detected (run 10). The formation of the red color might have been 83 .Hb u cm x ocoxomIH oomN QEDB :oHuommm ”Sum H n meromoam Hmpoa mHHH u Nmuoo HZO.H u mocoxomIHg .Hnm u cmHHOHOm .coHooeoe one oh cocoa no: HOHom can nHeo cHo .Hnm u mm a mumz .COHuomop one on oopom mm: mumz one MHz» :Hm III II I: I- O Hm azO oHH III I: I- I- O Hm ocooooa oOH m.m I: mm we OOH em gzo om m.m II NN m5 ow 3N mcoumo< mm o\: ocoxomIN HmcmxmchnuozIN Hmcmpdomlc .>:oo Hpnv uco>Hom com A oeHe H coHosoHaenHO nosoosa .pompzoopm umszpmo mm wmdmN H mcamVHooovzmu 59H: ocoxomI H mo :oHumHzEpomoncmm mnoocmono: .mH oHomB 8A .H x omH M cm H ocoxozuH HHHH n N: OO Hme.O u HocoxozuHLo H.m am OH H Hm mm EEO othoooog ImHmcaaVHOOOvca mH m mN mu m m: mp ocouoo< oquouOmc :mHmeaHVHOOOOem NH o\c Hmcmxom HmcmuqonI: HEpmV Hazy .>:oo uco>Hom umszHmo cam IszuozIN madmmopm DEHB m H :oHcsoHsonHO oosoooa o.Oomm no oeHnoo Ioo: :H OoooHootoocH +NHmnaaOHOOOng ceHs ocoxomIH no coHooHHEEOOObOH: .HH oHooe 85 the result of reaction of acid with acetone under the reaction conditions. C. Hydroformylation with Intercalated Rh(diene)(PPh3lz: The supported catalysts were generated by passing CO:H2 (1:1) through a suspension of Rh(diene)(PPh3)2T4 hectorite in acetone or DMF. Table 17 lists the results for the heterogeneous hydro- formylation of l—hexene with Rh(COD)(PPh3)2+-hectorite as the supported catalyst. When acetone is used as solvent, the reaction is very slow and unidentified products are formed at 1 atm. By increasing the pressure to 5 atm, the rate of reaction can be significantly increased (run 12). In the case of DMF as solvent the reaction was started im- mediately (no induction period) (run 13). Therefore, the reaction in DMF was much faster than in acetone. The filtrate from runs 12 and 13 (Table 17) were active toward hydroformylation. These results clearly indicated that such activities were due to the desorption of the active species in the solution. Significantly the desorbed rhodium complex is more active than Rh(COD)(PPh3)2+ in homogeneous solution. For example, the desorbed complex in DMF under— goes ~1A2 catalyst turnovers in 2A hours at 25°C (n/b = 3/1), whereas only N50 turnovers occur in A8 hours with Rh(COD)(PPh3)2+ as the catalyst precursor (pf. Table 1A, run A and Table 17, run 13). Since electrical neutrality 86 must be maintained inifluesilicate structure, it is Clear that the complex which desorbs from the negatively charged silicate surfaces cannot be cationic.p At this point two questions can be raised. First, why does Rh(COD)(PPh3)2+ desorb during the course of hydroformylation reaction, and second, why desorption in DMF is much greater than in ace- tone. Recently, Crabtree and Felkinl-23 found that the hydro— formylation of 1-Hexene in benzene with Rh(COD)(PPh3)2+ in the presence of triethylamine as base and one mole of triphenylphosphine gave reaction rates and product ratios n/b identical to those obtained with an authentic sample of RhH(CO)(PPh3)3. Moreover, they were able to isolate the latter compound from the reaction mixture in high yield. + H2/CO Rh(COD)L2 + L——> HRh(CO)L3 (ll) NEt3 S=benzene (Crabtree & Felkin) (1979) (11) Based on these results by Crabtree and Felkin together with our findings on the behavior of homogeneous and inter- calated systems (Tables 1A, l6, 17), it is likely that the active species is a neutral monohydride HRh(CO)x(PPh3)2, which exist in equilibrium with a cationic dihydride H2- Rh(CO)X(PPh3)2+ which is not active for hydroformylation: 87 + H2/Co + Rh(COD)L2 -———€> HéRh(CO)XL2 (12) A etone (x=l,2) H Rh(CO) L +-*'HRh(CO) L + H+ (13) 2 x 2 5-' x 2 The proton equilibrium proposed in Equation (13) not only accounts for the observed acid-base dependence of the homogeneous catalyst, but it also provides a mechanism for desorption of rhodium from the intercalation catalyst with- out loss of electrical neutrality in the silicate structure, or shown in Equation (1A) and (15). + + Rh(COD)(PPh3)2(solv) CO-H H2Rh(CO)x(PPh3)2(solv) ' 2 }> 1:1 (1A) H2Rh(CO)x(PPh3)2(solv)+ H+(solv)+HRh(CO)X(PPh3)2 (15) 88 Since the silicate sheets act as a base according to the Equation (15), the desorbed monohydride is taken out of equilibrium with the inactive dihydride and consequently the activity of the desorbed catalyst is greater than the activity of the catalyst formed directly from Rh(COD)- (PPh in homogeneous solution. 3)2+ According to the results listed in Tables 1A and 17, Catalysts showed better activity in DMF than in acetone. Previous studies of the effects of solvents were shown to have a marked effect upon the rate of hydroformylation reaction and in some cases, alter the product distribution.12u When Cth(CO)(PPh3)2 is used as a catalyst precursor for hydroformylation, as the polarity and concommitant bas- icity of the solvent increases, the selectivity of the catalyst also increases. The addition of excess triphenyl- phosphine to the polar solvent such as DMF results in a further increase in selectivity as well as a four-fold acceleration in rate. Also, the reaction in the polar sol- vent is initially fast and reaction decreases with time. The rate of hydroformylation in a nonpolar solvent such as benzene is initially slow, but reaction becomes faster as the solvent becomes more polar with the presence of product aldehyde.l2u At this stage it can be pointed out that the polarity of the solvent has an effect on the rate of reaction. The difference between acetone and DMF depends on their I 89 acceptor number (AN) and donor number (DN) which are listed as follows: Table 18. Physical Constants for Acetone and DMF. . Dielectric Acceptor Donor Solvent Constant Number Number Acetone 20.7 12.5 17.0 DMF 36.1 ---- 26.6 DMF is more polar than acetone and also has a higher elec- tron donor number and higher electron acceptor number than acetone. The acCeptor number (AN) and donor number (DN) 125 were defined by Gutmann et al. The acceptor and donor number empirically measure the electrOphilic and neucleo- philic properties of solvents. The acceptor numbers are derived from a change in 31F nmr chemical shift of Et 0? 3 dissolved in the solvent relative to (C6H5)2 POC1 as a reference. The donor numbers were defined from a negative AH value of the Equation (16) -AH = D.N. (l6) EPD + SbCl + EPDSbCl 5 5 where EPD corresponds to the electron pair donor solvent. 90 Since DMF has a higher DN and should accept a proton more readily than acetone, it is the more favorable solvent, for formation of a monohydride from the dihydride, which is known to be on active species for hydroformylation reaction. In the present work, additional studies were done with Rh(diene)(PPh3)2+ as the Catalyst precursor for hydro- formylation reaction of 1-hexene. When [Rh(COD)(PPh3)2]- B(C6H5)A was used for hydroformylation reaction, its ac- tivity was two times faster than [Rh(COD)(PPh ]PF6 as 3)2 a catalyst precursor. After A8 hr 50% of the l-hexene was converted to the aldehyde with n/b = 2.6. No substrate isomerization or hydrogenation was detected. Also, as mentioned before, according to the Equation (12), there is an equilibrium between the dihydride rhodium complex H2Rh(CO)x(PPh3)2+, and the monohydride rhodium complex HRh(CO)x(PPh3)2 and either HPF6 or HB(C6H5)2. Since HPF6 is a stronger acid than HB intermediate 92 The proton decoupled 31P resonance spectra of Rh(COD)- 4. PPh - a ( 3)2 consists of a doublet at 26.9 ppm (JP-Rh 1A6.5 Hz) (Figure 11a). The 31 P NMR spectrum of complex Rh(CO)x- (PPh3)2 which was formed by addition of CO to the Rh(COD)- (PPh3)2+ in acetone, shows a singlet at -3l.6 ppm at -30°C (Figure 11b), the complex gave a doublet at -32 ppm (JP-Rh = 75.7 Hz) (Figure 11c). These results indicate that a fast exchange occurs between two phosphine groups at room temperature. The 31P NMR spectrum of reactive inter- mediate (Equation 18) formed by addition of CO:H2 (1:1) 2 = 73.2 Hz) at and l-hexene to the solution contains Rh(CO)x(pph3) consists of a doublet at -32.5 ppm (JP-Rh -30°C (Figure 12a). The spectrum of an aged hydroformyla- tion solution (still catalytically active) showed a doublet at -3l-5 ppm (JP_Rh a 151.A Hz) which was assigned to phosphorus coordinated to the rhodium, and a singlet at '29-9 ppm due to 0PPh3 (Figure 12b). The hydroformylation solution eventually loses activity, even in the presence of fresh l-hexene. Catalytically inactive solution was dark red. The 31 P NMR spectrum showed only one singlet at -25.0 ppm (in acetone) due to P0Ph3. This result shows that no triphenylphosphine was coordinated to rhodium, and as a consequence of this, the catalyst had decomposed. At a ratio Of 2-Atl Of PPh3th, the catalysts did not lose activity and, also, no red solution was formed. As a result, it can be concluded that: l) the exchange of COD + with CO is fast (5 min), 2) in case of Rh(CO)X(PPh3)2 Figure 11. 93 31P NMR spectra of (A) [Rh(COD)(PPh3)2+]PF6 O-OIM in acetone at 25°C; (B) [Rh(COD)(PPh3)2]+ + CO, 0.01 M in acetone at 25°C, (0) at -30°C number of accumulated scans = 10000. 9A I . i MWWJ Awmwmmmw 480 312 NMR spectra of [Rh(COD)(PPh3)2]PF6 + CO-H2, 0.01M in acetone under hydroformyla- tion condition at -30°C (A) after 2 hr; (B) after 16 hr. 96 I I l I l ’80 '60 -4O -20 o 97 there is a fast exchange between two phosphine groups, 3) as long as two or more triphenylphosphines are coordinated to rhodium, the catalyst is active for hydroformylation reaction, A) the catalyst is very sensitive to trace amounts of oxygen which depress catalyst activity. 3. Utilization of P-P+IiCationic Phosphine Ligand At this point it was felt that the problem of rhodium desorption from the intercalation catalyst could be circum- vented by replacing the neutral ligand (PPh3) in a known hydroformylation system, RhCl(COD)PPh3), with the positively charged ligand such as Ph2PCH20H2P+Ph(CH2Ph), abbreviated P-P+. A similar approach has been used to prepare layered silicate catalysts for olefin hydrogenation.78 For this purpose the reactions of rhodium complexes such as [Rh- (diene)01]2, Rh(diene)+, [Rh(CO)Cl]2 with (P-P+) were in- vestigated. + l. |RhCl§COD)|2 + P-P Precupsor Catalyst System a. Homogeneous - The first system studied is based on RhCl(COD)P-P+ as the catalyst precursor. A proposed scheme for formation of catalytically active intermediate [RhH2- (C0)x(P-P+)212+ is described by Equations (19-21). %LRhC1(COD)12 + P-P+ + [Rhc1 98 [RhCl(COD)(P-P+)]BFu + p-P+ + [RhCl(COD)*(P-P)2](Bpu) 2 (20) + 2+ . + + 3+ [RhCl(COD)*(P-P )2] + CC.H2 z [RhH2(CO)X(P-P )2] (21) [RhH2(CO)x(P-P+)21+ z RhH(00)x(P-P+)§+ + H+ (22) where COD* is monodentate COD. Although [RhCl(COD)(P-P+)1- BF“ was found not to be active for l-hexene hydroformyla- tion at 25°C and 1 atm pressure, it showed activity at 100°C and 600 psi. Table 19 lists the results of this catalyst precursor in acetone, dichloromethane and benzene. RhCl(COD)P-P+ is an active hydroformylation catalyst, but it gives low normal to branched aldehyde product ratio (n/b : 0.6). The low n/b aldehyde ratio may be the result of an equilibrium between RhH(CO)X(P—P+) and RhHcoo Anny uco>Hom com HanmeN IHznuozIN R oEHB so one u :oHuonHomHa posoonm H» m m.n0mp:oonm umszumo mm 2mm+mImHQoovHonm 59H: ocoxomlH mo :oHumHaenomonozm mnoocomoeoz .mH oHome 100 .H\OON u rm\ozoxoguH .H.H u N:\OO mHno OOO mOoOOH Hozoeooo :H NH.O n HocogocIHL II. III I II . m :.m HN II wH Ho we a CH mH m.N mN II NN mm no 2 2 NH m.H mN : mN m: OOH m N NH o\: ocoxmclN Hmcmpcoo Hmcmxon Hmcmudomlc .>:oo HSVDEHB em com IHH:BMIN IHmnpozIN R zxm +dIm :oHOsoHpenHo cosoopa m.n0mHsOopm pmHHmomo mm +mImAaoovcmHo :on ocoxole do :oHuoHHEnomoHozm mnomcoNOEom .ON oHomB 101 hydroformylation of l-hexene with RhCl(COD)P—P+BFu as the catalyst precursor with ratios of P-P+ to Rh equal to 2:1, Azl, and 10:1. No activity was observed at room temperature and 1 atm pressure. The lack of activity at 25°C may be due to the lack of Rh-Cl bond cleavage and formation of a Rh-H bond. However, the catalyst was active at 100°C and 600 psi. The results in Table 20 show that increasing the ligand to rhodium ratio, effects the following: 1) aldehyde selectivity (n/b) is increased; 2) The rate of reaction is decreased; 3) The isomerization of (l-hexene to 2-hexene) is decreased. These results agree with those obtained when trans- RhCl(CO)(PPh3)2 is the catalyst precursor for hydroformyla- tion reaction. In 1968, Wilkinson et a1.121a reported that when trans-RhX(CO)(PPh3)2, X = halogene, was used as cata- lyst precursor, the active species formed by hydrogenolysis is RhH(CO)(PPh3)2 or RhH(CO)2(PPh3)2. These species were also formed when the stable complex RhH(CO)(PPh3)3 was used as the catalyst precursor. On the basis of these investigations and comparisons with related systems, two 121 consistent mechanisms were proposed; Dissociative (I) and Associative (II) pathways for the catalytic reaction. These differ in the mode of attack of the alkene on the catalyst. The overall hydroformylation mechanisms proposed by Wilkinson are shown in Figure 13. 102 ti «P Rh 4 i F4,..60 .1 I - - a R W 7 If La, I'v'IR fast L""R'II-co 5 .1. I V Rh“ V I." ‘- 1 L . CO co CO e/ test 11 / I4 (II) I L I L x 23 17'" I.’R'h lilflsii A"”,//’ R'h/H H2:sIow s I.’ l ‘L - _ CO 1 L a PP": Figure 13. Dissociative (I) and Associative (II) mechanism of hydroformylation reactions (according to G. Wilkinson, et a1. 1968). 103 In the "dissociative" pathway the complex 1 loses one phos- phine, (path Ia) and affords the unsaturated hydride 2 which coordinates to an olefin forming 3 (path b). Insertion (path c) affords the unsaturated alkyl, A, which adds a phosphine to form the saturated alkyl, 5, (path d). Wil- kinson speculates that in step 5 the opposite mode of ad- dition may be favored. Carbonyl migratory insertion (path e) affords the unsaturated acyl, 6. Oxidative addition of hydrogen to the unsaturated acyl, 7 (path f), is proposed to be the rate determining step. This is plausible in the sense that the overall reaction rate is first order in [H2]. Such an oxidative-addition should be accelerated by phos- phine ligands. However, the available evidence does not rule out a binuclear elimination as the product-forming step (g, h). The final step in Wilkinson's proposed mechanism is a fast, irreversible, intramolecular, reduc- tive-elimination of, I (path g) affording, 2 which acquires CO regenerating l (path h) and thus completing the catalytic cycle. Note also the unusual gig orientation of phosphines, which Wilkinson postulates for this cycle. Wilkinson also proposed a questionable associative mechanism (Figure 13, path II), path 1, which involves an unprecedented 20- electron intermediate, 9. The remaining steps (J, . . .) are the same as those in the dissociative-reaction cycle. Therefore, on the basis of the results which were ob- tained by positively charged ligands (Table 20) and those 10“ reported for rhodium -PPh3 complexes, it can be mentioned that by increasing the concentration of free ligand, the associative pathway is favored over the dissociative path- way and more product selectivity is observed. Wilkinson also reported in the reversible addition of LnM-H to alkene to give an alkyl complex, there are two main factors which are not independent.121 The direction of addition may be Markownikov or anti-Markownikov. Only Markownikov-addition leads to isomerization. The direction of addition will depend on the polarity of the M-H bond and steric effects in the presence on the metal of ligands of high n-acidity, such as carbon monoxide will increase the polarity of the M-H bond in the direction M5'—H5+. This will increase the extent of Markownikov addition. The presence of weaker n-acid ligands will have the opposite effect. The presence of bulky ligands such as R P can 3 generate substantial steric inhibition to the formation of the metal alkyl, especially where R is aryl. The steric interaction will be at a maximum when such groups are trans to each other and mutually cis to the hydride group or the alkyl formed from it as in (Figure 13, 2a). When R3P groups are cis as in (Figure 13, l), the steric in- hibition to alkyl formation will be minimized though prob- ably not negligible. An increase in L+/Rh ratio will form the associative pathway and more steric n inhibition. Therefore, more product selectivity is observed and the 105 rate of hydroformylation reaction is decreased, because the associative pathway is slower than the dissociative path- way. Also, isomerization of l-hexene to 2-hexene is de- creased because steric inhibition is increased. In conclusion, it can be mentioned that electronic and steric factors both have effect on selectivity. In the case of bulky ligands such as R P, steric factor is probably 3 more important than electronic factors, but in some cases the electronic factor can play an important role on selec- 126 2) tivity. For example, when RhClCO(PPh2NRlR is used as a catalyst precursor for hydroformylation of l-hexene, the selectivity is dependent on the nature of R1 and R2. In fact,the highest aldehyde selectivities are obtained with f:‘ electron withdrawing aminophosphine (¢2P-N __ ) and the lowest aldehyde selectivities are observed with ¢2P-NMe2, On the basis of these investigations and those we ob- tained, it can be mentioned that by increasing the concen- tration of bulky ligands in solution, aldehyde selectivities can be increased. Also by changing the nature of substi-s tuents on the ligands, it is possible to change the selec- tivities. 2. Hydroformylation of l-hexene with Intercalated Catalysts The active species for hydroformylation was generated by the addition of CO:H (1:1) to a solution of 2 106 + RhCl(COD)P-P++P-P at 600 psi and 100°C. Then it was inter- calated as follows: (acetone) Na+(solv) + ARh(CO)x(P-P+)§+ ARh(CO)x(P-P:)2+ _______________ A 3 H, Cl _______________ (2“) Table 21 lists the results which were obtained by the homogeneous and heterogeneous systems. By comparing runs 20, 21, it can be seen that the product distribution of the heterogeneous system is different from the homogeneous system. Although the rate of hydroformylation with the supported system is lower than the homogeneous system, the ratio of normal to branched aldehyde is increased. In runs 22 and 23 in which the ratio of P-P+:Rh is uzi, iso- merization of l-hexene to 2-hexene (cis + trans) is sig- nificantly decreased and selectivity is increased. In the supported catalyst system, the production of linear aldehyde is increased considerably in comparison to the homogeneous hydroformylation. Previous studies on homogeneous hydroformylation of olefins indicated that there are several pathways for olefin insertion into the metal hydride bond. Figure la AI .Hnowm cmnocoxozlao smuocoxozlan .HHH n m:\oo memo com mOoooa mocouoom c“ m:.o u mocoxoclagm .Huoom 107 I .ll' ‘ lI-J'I .I: m.m o w II mm mm mm ma ocmuwfimohmch mm Amzoocomosozv +mnm m +mImAQoovzmHo mm m.m II mm II mm mm 50 z n :.m In mm s: mm V mm om NH oooeosoosoese Hm m.H u- mm s . mm m: 00H m sfiosoocomoeozv , aua H + +auaAooovsmHo om n\: ponuo ocoxmmlm Hmcmucom Hmcmxoz Hmcmuqomlc .>:oo Ar: umhahumo cam usssomnm ussceozum a mafia zxm hosesoasemaa oosooaa . mum m + Inooovnmao cud; ocoxozla mo cofiumH>ELomopozz mzoocowopouo: pcm mzoocoono: .Hm canoe 108 . ..e.oo.z= u 2:. women :ofiuauuposoma manfimmoo zuaz coauoaasnohopcaz on» go Emucmnooz .za opzwfia 5.9-8.3. 39.8.3. 3331...... 5.93:. genera—nu... 8:81:33. 838.323.. 2.38.1.5 1.5.2.3.. 3.323.. .. NP =3: *9 9.. O /o:.cs¢ 4|. 3.60:5... 1|"... 2-5...- “ ..GL .. -s o\ _ ..+ . 8e . a... .w £6 ....o ....o ..l... .._ / > >. _ h V O ..O-..ws.4nu nulls. ..Ou.o._.c|¢ flu» 31.51.515-- = 0F 9.. OP \ 2|: 2.. / . uil . . \on.n.T.Us- Jul. 318-515-: “W 3-5-5... .. . o ..O .1 5w 8 . / .0 4|... 0 M: N d. ..G:..on...ou. H ..B .530:- «Hw 3.+..5I..o1..cs.- > — 2— a. - ._ m. ..:- a. a ..:... m /on.=o:.=uu..cuu Al. 1-8:..Ou..6-..o-.. nu ..:..On...on...o-.. all» .Lnfiwuaus o\ 2+ 8+ 109 shows the mechanism of hydroformylation with possible iso- merization with (HM(CO)m = Hm). Three isomeric aldehydes can arise from a metal carbonyl hydride complex. Further studies showed that the coordination of two or more bulky ligands to the central atom would lead to the formation of aldehyde (15,16). By increasing the concentration of ligand (PR3) in solution the selectivity of linear aldehyde was increased. It can be concluded that more bulky groups in rhodium carbonyl complex would favor intermediate 5. This in turn leads to the formation of linear aldehyde as a major hydroformylation product. By comparing the sup- ported catalyst with homogeneous system, a similar explana- tion can be proposed as follows: ' Two intermediates 3 and 9 in Figure 15 would lead to the formation of branched and linear aldehyde respectively. The methyl group in intermediate 3 has interacted sterically with both the P-P+ ligands and the silicate layers. On the other hand the latter interaction should be reduced in intermediate 9. Thus intermediate 9 should be favored in the inter- I calated state and should favor formation of linear aldehyde. Also it was observed that in the supported catalyst systems the substrate isomerization was decreased, and the rate of hydroformylation was lower than the homogeneous system. Previously reported investigations of homogeneous hydro- formylation have indicated that in the case of olefins llO ocoxocla 3 I C . QBMANIQTM... -._.A z I _ + 0:0 0|- :0 .muoocm ouMoHHHm on» coozuoo mo coaummfiposomfi new coauwamspomoppzn Lou mzmznuma oHnHmmom .m. osowam Am. Am. A». / \ Z/ N j Z I!- a.---_..- .-I.- ..e... a, m All-III N . v8}-.. fill-I- ~=o\ : ‘ ammo . x 8. .3 m .-m _\ nlhv . ..... n .\ '4’ 1 J/ z .IMHMWk .2. / E . .3 E . ammo, . .mmzo/ . H E. . \ . \ :2. + lzn Adlll 5!: H ..:-zxu «.8 4., _ :60 m \ I m . , m .. . = .5 moi-.. .8 .. 111 higher than propylene in chain length, double bond shifts can occur.8uf Isomerization in cobalt catalyzed hydro- formylation reaction is enhanced by low carbon monoxide partial pressures (50 atm) and higher reaction temperatures USO-190°C).127 Complete isomerization of l-dodecene was observed by Asinger and Berg under hydroformylation conditions at 150-200°c.128 In contrast, when organophosphines or organoarsines are added to rhodium catalyst systems, isomerization can be completely suppressed so that the products obtained cor- responds directly to the olefin charged. Asinger, Fell, and Rupilius129 demonstrated the complete inhibition of isomerization using octene-l and octene-h and a Bu3P complex of rhodium in the presence of excess Bu3P. They obtained substantially the same results when they used tricyclohexyl- phosphine as a ligand. The phenomenon of nearly complete retardation of double bond migration was also observed under nonhydroformylating conditions using octene-l and HRh(CO)(PBu)3 in the presence of excess Bu P. Under the 3 same conditions, a phosphine free system yielded an equi- librium distribution of isomers. Similarly, Evans, Osborn and Wilkinson121a observed the inhibition of isomerization of l-pentene by using HRh(CO)(PPh3)3 in the presence of excess ph3P. In addition, they found that H-atom exchange was much more rapid than isomerization using DRhCO(PPh3)2 and l-pentene, but that exchange was completely eliminated 112 in the presence of excess PPh3. Apparently, the formation of a five-coordinate tris-triphenylphosphine complex pre— vents coordination of the olefin to the metal and there- fore only subsequent isomerization. According to this evidence andtfluepossible pathways (Figure l“) for isomerization of olefins under hydroformyla- tion conditions, it can be proposed that the isomerization pathways are also available under intercalation conditions, (Figure 15, pathway III). As explained before, the intermediate 8 leads to linear aldehyde while the intermediate 2 would result in both branched aldehyde and isomerization of l-hexene to 2-hexene. In fact the presence of a methyl group in intermediate 3 and its steric interaction with the other ligands and silicate layers should cause this intermediate to be less favored intermediate 3. Therefore the hydroformylation reaction gives linear aldehyde as a major product, in all inter- calated catalyst system. By increasing the concentration of bulky positively charged ligands between the layers I the amount of isomerized olefin is significantly decreased. 3. Solvent Effects To investigate the effects of solvents, the active species which was generated from RhCl(COD)P-P+ + lP-P+ and CO:H2 at 600 psi and 100°C was utilized for hydroform- ylation in DMF and in benzene. Table 22 lists the results 113 .coom coon mm: :ofipdpomoo pcmofimficwfim omwo man» CH: .Huowm A cmnocoxozla o .Huowm u cmuocoxozlan .HHH u m:\oo mama ooo muoooa .oCOpoom CH $3.0 u monoxozlagm mmwo cofiuomop panofieficmfim oz ma oooumamopoucH pm @500 m II mm :H mm ow m nmsoocomoso: +m-m H +m-dfiooovcmao mm *mzo 0.0 HH m m: m: mm :m opoumamopoch mm azc m... o. m mm mm co. m oAnsoocomoeozv +m-m H +m-mflooovnmao :m .>Hom n\: Losuo ocoxomlm Hmcwxo: Hmcmuoomuc .>coo An. Lomasoopm 22m -.a:ooz-m a osee seafloooo n :ofiusnfisumfio posoopm zxm w.w=mo cam .mza cfi.homL:oopm omzamuwo mm +mlm Ifiaoovzmao spa: ocoxo:-H mo coaumHzELoQOLcm: msoocowopouom 0cm msoocoono: .mm canoe 114 of these experiments. The results of Table 22 show that the activity of the catalyst and the product distribution depends on solvent. Homogeneous hydroformylation in DMF is faster than in benzene, because the solvation of the positively charged catalysts in polar solvent (DMF) is better than in nonpolar solvent (benzene) runs (2u,26). In the supported catalyst system the aldehyde selectivity and the rate of reaction depends on two factors: 1) The extent of swelling of the interlayer. 2) The polarity of solvent. In the supported catalyst system when DMF was used as the solvent (run 25) a low n/b ratio is observed. Also, significant desorption occurs during the hydroformylation reaction. In benzene no significant reaction ( 5%), (run 27) is observed. In acetone (Table 21, run 21) the n/b ratio is higher than in DMF and no desorption occurs. Table 23 lists the 001 basal spacings of Na+-hectorite partially exchanged with the positively charged rhodium complex. According to this table and previous studies; the interlayer spacing increases as the polarity of the solvent increases. In benzene, which is a nonpolar solvent, no significant swelling is observed. When acetone is used as solvent the interlayer spacing increases from 23.1 to 25.1 A, which agrees with the existence of solvent between the layers. Based on the difference between the thickness 115 Table 23. 001 Basal Spacing of Na+-Hectorite After Partial Exchanged with RhCl(COD)P-P+ + P-P+ Under Hydro- formylation Condition. 001 Basal Condition Spacing (A) Dry 18.4 Wet (Acetone) 20.5 Wet (Benzene) 18'” Wet (DMF) ’ 2“°5 116 of the silicate sheets (9.6 A) and the observed (001 X-ray reflection (18,u K), it can be estimated that the average thickness of the interlayers (8.8 A) agrees well with the values expected from molecular models for a monolayer of Rh complex with positively charged ligands. In the case of DMF as solvent, the thickness between silicate layers is larger than acetone because of its higher polarity relative to the acetone. The desorption problem with DMF, probably is due to its higher DN numbers relative to the other solvents (Table 18). According to the Equation (25) DMF can be coordinated to the central atom by displacement of some P-P+. Finally, the resulting complex was neutral and it was desorbed from the layered silicate and P-P+ was remained between the silicate sheets. The IR studies of the filtrate solution didn't show any P-P+ band posi- tions although (CEO) stretching was observed at the region 2000 cm‘l. At this stage it can be concluded that DMF and benzene are not good solvents for hydroformylation of l- hexene with supported positively charged rhodium complex. HRh(CO) L22+ + DMF _____.. L+(DMF) + HRh(CO)XDMF (25) 117 0. Characterization of the Homogeneous Hydroformyla- + tion5Cata1vsts.ContaininggP-P A 31P NMR study was undertaken in an effort to better understand the nature of the homogeneous hydroformylation + catalysts containing P-P , an attempt was made to compare these results with those as obtained for triphenylphosphine rhodium complexes. It was felt that 31P NMR studies would allow the charac- terization of the catalyst precursors and the active species which was exchanged into the Na+-hectorite structure. Ace- tone d6 was used as the solvent in these studies. As it is described in the literature,78 P-P+ cleaves the chloride + bridge of [RhCl(COD)]2 to produce RhCl(COD)(P-P )BFu at 1:1 P-P+:Rh ratio. %[Rh01(c00)]2 + P-P+-->-Rh01(COD)P-P+ (25) Figure (l6a,b) show the 31? NMR spectrum of RhCl(COD)- P.P+ at -30°C. The two non-equivalent phosphorus atoms and the rhodium give rise to an ABX pattern. The spectrum 130 At -30° was analyzed according to Becker's treatment. + in acetone, 6p 8 -30.l ppm, 5p = —27.l ppm, JPRh = 150 Hz, JP-P+ = 58.9 HZ, and JP+-Rh = —5.6 Hz. These results were similar with those reported (lit.,131 at + 28°C: 9 = ‘29-5 ppm, 5p = “27-3 ppm, JPRh = 1&9 HZ: JP_P+ = 5M Hz, JP+_Rh = 7 Hz and at —80°c 6p = -3l.8 ppm. 118 Figure 16. 31? NMR spectra (A,B) of RhCl(COD)P-P+BFu 0.01% in acetone (d6) at -30°C, number of accumulated scans, NS = 10000. A l l l _ I l -40 -30 ‘20 .10 0’ B _; L l l L 1 1 -32 -31 '30 -29 -28 -27 -26 120 + 5p = -27.3 ppm, JP-Rh = 153 Hz, J + = 62 Hz and J P-P P+-Rh = -6 Hz in CH2C12 as solvent). A solution formed by the addition of another equivalent of P-P+ to RhCl(COD)(P-P+) give the 31? NMR spectrum, shown in Figure lu. The spectrum consists of a multiplet 5Pc = -u2,u ppm JPc-Rh = 2lu.8 Hz, a doublet at dp = -27.6 ppm JP—P+ = 34 Hz and a multiplet ABX pattern between -29.9 to -28.8 ppm (dp = -29 6 ppm and 5p+ = -28.7 ppm). Based on NMR results the structure formed from 1:1 RhCl(COD)P-P+ P-P+ is proposed to be the PcPc+ NMR lines are assigned to the positively charged ligand which is cis to the two trans ligands (Pt-Pt+). Also, no free positively charged ligand 31 (P-P+) was detected by P nmr spectra. .4. Cl P - \ /t t /’Rh ‘\ P +"Pt Pc\p + t ‘c Similar behavior has been reported in literature for tri- phenylphosphine:78 %[RhCl(COD)]2 + pph3 . RhCl(coo)PPh3 (27) 2RhCl(COD)PPh + 2PPh + RhCl(PPh3)3 + RhCl(COD)PPh (28) 3 3 3 121 31P NMR spectrum of RhCl(COD)P-P+-P-P+ in 0.01fl solution of acetone (d6), NS a 10000. Figure 17. 122 -'20 ~10 -30 -4'0 -50 123 RhCl(COD)PPh3 : RhCl(COD) + PPh3 (29) The 31? NMR spectrum of a RhCl(COD)PPh3 at 30°C showed a doublet at 5p = -30.6 (JP-Rh = 151 Hz in CH2C12). The addition of another mole of triphenylphosphine produced RhCl(PPh3)3 as a major product. No free triphenylphosphine was detected at 28°C by 31P NMR. On the other hand, by lowering the temperature to the -80°C some free triphenyl- phosphine was detected, (lit78 31? NMR. 5pc = -h8.9 ppm, épt = -32 2 ppm. JPCRh = 192 Hz, JPCPt = 38 Hz, J t = 1U6 Hz). A solution of 1:1 RhCl(COD)P-P+:P-P+ was treated with CO:H2 at 600 psi and 100°C.‘ The final solution was divided into two fractions under nitrogen. The first fraction was 31 used directly for P NMR studies and the second fraction was taken to dryness in vacuum and then it was redissolved 31P NMR spectra of both fraction were 31 in acetone-d6. The the same. Figure 18a shows the P NMR spectrum of mentioned solution. There are two sets of resonances, each containing six lines. Chemical shifts and coupling constants are listed in Table 2A. No free (P-P+) was detected. Therefore, two P-P+ ligands are coordinated to rhodium as the central atom. In addition a solution of 1:1 RhCl(COD)PPh3:PPh3 was treated with CO:H2 at 600 psi and 100°C. The 31? NMR spectra of that solution shows a doublet at 5p = -31 ppm 124 Figure 18. 31P NMR spectra of (A) RhCl(COD)P-P++ P-P+ + co-H2 (1:1) 0.01g in acetone (d6) at -30°C. (B) RhCl(COD)PPh3 + PPh3 + CO/H2 (1:1), 0.01% in benzene at 25°C. NS = 10000. 125 -3O -40 _l -50 126 (JP-Rh = 128 Hz), and another doublet with lower intensity at p = -3l.l ppm (JP-Rh = 128 Hz) at room temperature in benzene. No free triphenyl was detected in the 31? NMR spectra (Figure 18b). Also, no signal belonging to hydrogen attached to rhodium was detected by NMR studies. 4. Table 20. 31? NMR Data for 1:1 RhCl(COD)(P-P )zP-P+ Under Hydroformylation Conditions. p + JP-Rh JP-P+ Set (ppm) (ppm) (Hz) (H2) 1 -3l.5 -29.1 12“.9 31.2 2 -32 -28.5 120.9 18.7 By comparing this spectrum with the one obtained for solution of 1:1 RhClCODP-P+:P-P+ + (CO:H2) in Figure 18a, it can be concluded that the active species which is formed by positively charged ligand, has the same structure and chemical behavior as triphenylphosphine. On the basis of this evidence, two structures can be proposed under hydroformylation conditions. // Rh--- - - - -Rh and \ /' \ "U I "U 'U\ / 127 The dimeric structure is analogous to that of [Rh(CO)- (PPh3)2]2, which has been proposed by Wilkinson,87a to form when HRh(CO)(PPh3)3 is used as a catalyst precursor for hydroformylation reaction. In the presence of carbon monoxide a dicarbonyl complex was formed: HRh(CO)(PPh3)2 + 00 : HRh(C0)2(PPh3)2 (30) which can then dimerize according to the reaction C0 + 2HRh(CO)2(PPh3)2 fi' [Rh(CO)2(PPh3)2]2 (31) 2 Wilkinson also reported that a red dimer is formed by bubbling nitrogen or argon gas through a solution of [Rh(C0)2(PPh3)2]2 N 2 [Rh(CO)2(PPh3)2 58 [RhC0(PPh3)2]2 + 200 yellow red In the presence of dichloromethane or ethanol the red dimer can be isolated as [Rh(CO)(PPh3)2S]2 O H /\ D (Ph3P)2(s)Rh;:~;;Rh(s)(P h3)2 C H O 128 The red dimer exhibit the following IR CEO stretching. 8 Lit: 7a IR for [Rh(CO)(PPh3)2, CH2012]2 compound. In Solid In Solution 1765 W 1980 S 1739 S 17140 S The difference in the solid state and solution IR bands was attributed to the presence of only dimeric in the solid state and the presence of both monomeric and dimeric in solution. The monomeric and dimeric carbonyl dimers are formed from HRh(C0)(PPh3)3 in the absence of coordinated chlorine. In 1970 Evans et al.1218. suggested that rhodium catalyst precursors containing chlorine can form from an active hydride complex by the following reaction sequence: $1 +H Ph3P\.? ,H H\\ .PPh3 2 “ 1” - I” Ph3P-Rh-CO -——9 (an i; (Rh PPh3 slow P113? CO\Cl Ph3P \CO The 31Piflflispectrum Of RhCl(CO)(PPh3)2 shows a doublet at dp = -29.1 ppm (JP-Rh = 125 Hz) in CD013. This coupling constant is the same as that obtained for 1:1 RhCl(COD)P-P+: + P-P + (CO+H2). However, it was realized that for identi- fication of exact structure of the active species further information was needed. 129 For this purpose an attempt was made to crystallize the complex from solution. Crystallization was achieved by concentration of an acetone solution of RhCl(COD)P-P+ + P-P+, followed by separation of solid from pentane or from a mixture of dichloromethane and ether or CHCl3, (yield 80%). The color of the solid product was yellow. Figure 19a shows the IR spectrum of this species crystallized from pentane. r A strong band at 1975 cm.1 is assigned to a CEO stretching vibration, and the band at 1700 cm.1 is attributed to the carbonyl stretching vibration of acetone. The bands around ; 1600 cm-1 are most likely due to phenyl group skeletal E l l and lUAO vibrations. Bands around 1500 cm- , 1H80 cm- cm"l could be assigned to the methyl group scissoring vibra- tions also might be due to aryl skeletal vibrations. The bands at 1300-1150 cm.1 are probably due to phenyl group in plane C-H bending vibration. The broad band at 1120 cm-1 to 1000 cm-1 is characteristic of tetraphenyl borate anion.119 In the region 850 to 600 cm”1 the three relatively sharp bands are assigned to phenyl group C—H out of plane bending vibrations. The spectrum confirms the presence of P-P+, CO and solvent (acetone) which are coordinated to the rho- dium as central atom. A sample prepared by crystallization from concentrated solution in pentane gave the following chemical analysis for [RhCl(CO)(P-P+)2(acetone)2](BFu)2 Found: Rh, 6.7%; P, 8.28%; C, 61.U%; H, 5.31%, C1, 2.5% Calc.: Rh, 6.9%; P, 8.3%; C, 61.1%; H, 5.38%; Cl, 2.h%. Figure 19. 130 Infrared Spectra of 1:1 mixture of RhCl(COE>)-—' + + P-P :P-P in acetone under hydroformylation condition (A) crystallized in pentane; (B) I°€3" crystallized in CHC13, 131 Dean 600.0 GOO? D 1 emu o9. opal com. 82 q 4 _ l O3 81 com com coo p 2.51. q q q q q - u H DOOM GOO? . 132 Figure 20. Infrared spectra of 1:1 mixture of RhCl(COD)- + P-P+:P-P + l-Hexene under hydroformylation condition (recrystallized in CHCl3). 133 can Be GOO GOO» 000v OOmw q oc&p q OO£N 13A The single, strong C0 band at 1975 cm"1 in the IR spectrum confirms the presence of a terminal carbonyl group, not a bridging carbonyl. Also, when the complex is recrystallized in CHCl3 or mixture of CH2C12 and ether no strong bands due to bridging C0 are seen around 1800 to 1700 cm.1 (Figure 19b). Figure 20 also shows the IR spectrum of Cth(COD)P-P++P-P+ under hydroformylation conditions. Therefore the IR evidences and chemical analysis suggests that the product is best formu- lated as [RhCl(CO)(P-P+)2](B(C6H5)u)2°x Acetone (X = 2,3). + + 5. Rh(diene) . P-P Precursor System Since hydrochloric acid is formed in the conversion of the [RhCl(COD)]2 precursors to [RhH(CO)(P-P+)212+, the hydroformylation reaction occurs under acidic condition. The acidic solution does not favor hydroformylation reac- tion of l-hexene, but it favors isomerization of l-hexene to 2-hexene. At this stage it was thought that Rh(diene)+ complexes (diene = COD, NBD) which do not contain chlorine, would be a better precursor for hydroformylation and might decrease the extent of isomerization of olefin. The reaction sequence which was examined is described below AgBFu + [RhCl(COD)]2 + [Rh(COD) JBFH + AgCl(s) [Rh(COD)]BFu + 219-?+ + [Rh(COD)(P-P+)2]3+ 135 CO:H2 (1 1) [Rh(COD)(P-P+)233+ e€> [HRh(CO)X(P-P+)2]2+ + H+ Catalyst intercalation was achieved by exchange of the active species with Na+-hectorite: + Na (solv) + HRh(CO)x(P-P+)22+.__;. HRh(CO)x(P-P+)2 + Na+ Table 25 lists the results for hydroformylation of 1- hexene with the catalyst at 600 psi and 100°C. The hydro- 3 formylation rate and selectivity were found to be the same in case of Rh(COD)+, 2P-P+ and Rh(NBD)+, 213-2+ in both homo- geneous system (runs 28, 30) and also in heterogeneous case (runs 29, 31). By comparing homogeneous (runs 28, 30) and intercalated system (runs 29, 31), one may conclude that intercalation significantly decreases the extent of olefin isomerization and increases the n/b aldehyde ratio. These results clearly show that the absence of chlorine in the catalyst system, which has the potentiality to produce hydrochloric acid, decreases the amount of olefin isomeriza- tion. No desorption of rhodium complex occurred in these systems, since the filtrate was inactive. Chemical analysis of the intercalated catalyst shows: Rh, 0.27%; P, 0.50%. This means the ratio of P-P+:Rh = 2:1. Rh(COD)+ and Rh(NBD)+ react readily with trace amounts 136 .noosoosd coaoooos oo.e.r:oo.::o .Huomm u zmuocoxozla MHHH u m:\oo mama oom MOoooH moCOQoom :a 83.0 n monoxozlagm w.m II II mm mm om :m nonmamopoucH Hm m.a II N am no 00H m mzoocomoEozv mum m + .+..omz.sm. om o.m m In mm om om :m acoumamopoucH mm o.m - 0. cm co co. m .nooccomoeoz. +m-m m .+m.aoovnm. mm o\: opozuo ocoxomlm Hmcmxoz Hmcmudomlc .>:oo Ass mongooopm cam -Hmseoz-m n 05.9 ewenmm zxm R soaozoaaenso nosoosa Iopm umzamumo mm moxoam .mEoumzm poumamopouCH ccm msoocoonoz :« whompzo Eoo +Aocofipvcm spa: ocoxomla no cofiumazspouopozm .mm manme 137 of oxygen at P-P+ = Rh(diene)+ a 2‘1- The active species is still very sensitive to oxygen. The oxygen sensitivity limits the utility of these systems. Increasing the P-P+: Rh ratio from 2:1 to 10:1 allowed the catalyst to be re- cycled several times without a significant decrease in activity (Table 26, run 32). Also, it is found that the rates of hydroformylation reaction with [Rh(COD)]BFu + F 10 P-P+ and [Rh(COD)]BFu + lOPPh3 were approximately the same (runs 32, 33). For the intercalated catalyst system, the active catalyst was generated by the addition of CO and H2 to a solution of Rh(COD)+, 10 P-P+ and then allowing i the active species to exchange with hectorite. However, l-hexene hydroformylation with this intercalated catalyst in acetone was immeasurably slow. It was thought that by saturating the interlayers of Na+-hectorite with positively charged ligand (P-P+), and then allowing the surface-bound ligand to complex Rh(diene)+, one might be able to achieve better accessibility of the intercalated rhodium. Therefore Na+-hectorite was exchanged with positively P-P+. X-ray analysis showed the 001 basal spacing to be 18.8 3, which indicates one monolayer of positively charged ligand between the silicate sheets. Figure 21 shows the IR spectrum of Na+-hectorite (A) and of P-P+/hectorite + Rh(COD)+ before hydroformylation (B) and after hydroformylation (C). By comparing the three spectra, one can identify the presence of coordinated CEO 138 .poELom Coon mm: onQeoo oHnmpm zpo> m .ooOOH «Hod com um H.H n mm\oo CoHpprm Conga +mAaoovau Cqu coownoxo Con» .+mnm Cqu ooumpsumm Coon mm: ouHCouoozlmz am Cam CH .Hnoom M CmuoCoxomnH ”Hzmv Com CH .Huoom CmuoCoxomlH mmsooCmmoEo: CH mHmQ ooo mooOOH moCouoom CH 2:.o u moCoxolegm m.m OH - om es cm as +Hooovsm.+a-m Hm H.m m s om , so OOH H +d-aOH + +H.ooovsm. mm H.m : w mm om OOH H msaaoH + +H.ooo.sm. mm C\C nCoCuo oCoxom-m Hmmeo: HmCmqumnc .>Coo ACV Comasoopm Com nHzCuoz-m . H oEHE Eoummm zxm n soHosoHsenHo oesoosa .Eoumzm poumHmoCouCH CCm msooCom IoEo: CH Compsoopm umszpmo mm +HoCoHpvcm Cqu oCoxole Ho CoHumHzEComonoaz .om oHnt Figure 21. 139 Infrared spectra (KBr disks) of A, Na- hectorite. and (B) the P-P+-hectorite + Rh(COD)+ system before hydroformylation. Spectrum C is for the P-P+-hectorite + Rh(COD)+ system after hydroformylation. 1H0 :8 8a. 8... - 89.. 83 o H can 2.3 . 3.. 8m. . 8m. 8..“ Sam 33 0&0 . 00«w 141 in the spectrum after hydroformylation due to the strong band at 2000 cm-1. The bands at 1H80, lAAO are assigned to methylene group scissoring vibrations (P—P+ ligand) and three bands around 750-650 cm‘1 can also be assigned to the phenyl group of the positively charged ligands. The P-P+- hectorite + Rh(COD)+ system was active for hydroformylation reaction as shown in Table 26, run 3h, it can be seen that (a) the n/b aldehyde selectivity was increased relative to E homogeneous solution, (b) no isomerization of l-hexene to 2-hexene occurred and (c) the rate of hydroformylation was E; relatively slow. Also, no desorption of rhodium complex was observed. This supported catalyst was found to be one of the best systems for hydroformylation reaction. 6. |Rh§C022Cl|2 + P-P+ Catalyst Precursor System A catalyst precursor was prepared by allowing [Rh(CO)2- C1]2 to react with P-P+ as proposed below:_ benzene + ————> 2RhCl(CO)2P-P+ [Rh(CO)2C1]2 + 2P-P warm benzene + ~3>RhCl(CO)(P-P )2 + Rh Carbonyl RhCl(CO)2P-P 2” h I‘ + The IR spectra of RhCl(C0)2P-P+ and RhCl(CO)(P-P )2 exhibit a band at 1975 cm“1 which is assigned to a terminal C50 stretching frequency and two bands around 1H80 and luuo cm"l 1N2 which are assigned to the CH2 scissoring or in plane de— formation of phenyl rings. Three bands at 750 to 690 cm-1 are assigned to C-H out of plane deformations of the phenyl rings bonded to phosphorus (Figure 22). These results were in agreement with those reported for the reactions of [RhCl(C0)2]2 with triphenyl phosphine132 [Rh(CO)201]2 + 2PPh3 + RhCl(CO)2PPh + + RhCl(CO)(PPh3)2 + Rh Carbonyl 3 RhCl(CO)2PPh3 has been assigned a trans structure. The complex exhibits a terminal CEO vibration at 1980 cm-1 and a Rh-Cl stretch at 295 cm'l. The same behavior was observed when [Rh(CO)2Cl]2 was allowed to react with P-P+. [RhCl(CO)(P-P+)2](BFH)2 was obtained as a pale yellow precipitate after the reaction of [Rh(CO)2Cl]2 + 2P-P+ in benzene at 25° for 2“ hr. The active species which was generated by the addition of CO/H2 to a 1:1 solution of P—P+:[RhC1(C0)(P-P+)2] at 600 psi and 100°C was exchanged with Na+-hectorite in a nitrogen filled glove box. Table 27 lists the results for 1U3 .Huowm n CmuoCoxomlH .0o00H ch HmQ 000 .oCouoom CH $2.0 u moCoxomlHHm m 0v mm HF mm 0H poumHmoCopCH m 0m mm :m 00H m mzooCoono: m-mm m + H+d-dv HoovsmHo m H\C oCoxom-m Hmmeo: HmCMQCo: . .>Coo. AC0 Eoumzm IHHCquIm a oEHE zxm & COHuanLumHQ QOSUOLH ImCm N m..HOmcHSO anHoooo no +o-d . HHoHoovsm. seHs osoxom-H co soHomHHesoCosoH: .sm oHooe 1L1“ Figure 22. Infrared spectra (KBr disks) of RhCl(CO)2- + .. .1? P P BJ-uo 145 000 000w 000m 000? 00a 0&v 00Np 1&6 hydroformylation of l-hexene with the homogeneous and inter- calated catalyst systems. The results indicate that the n/b aldehyde selectivity was increased and the isomeriza- tion of 1-hexene was decreased by intercalation. In all of the intercalated catalyst systems investi- gated in this work, it was observed that the actual rate of hydroformylation was always slower than the corresponding ‘1 rate of hydroformylation in homogeneous conditions. The immobilization of the homogeneous catalyst probably results in loss of mobility and accessibility of the metal complex, which should have a great influence on the rate of reactions. ' SUMMARY This dissertation has shown that cationic rhodium com- plexes such as [Rh(diene)(PPh3)2]+A: where diene = NBD or COD and A-= PFE, B(C6H5);, are active catalyst precursor for hydroformylation reaction at 25°C and 1 atm. The conver- sion of l-hexene was appreciably lower in acetone than in. DMF. The rate of reaction at 600 psi and 100°C was faster than at room temperature and 1 atm Pressure, but the amount of isomerization increased and the normal to branched aldehyde ratio decreased. By increasing the PPh3;Rh ratios to 10:1, aldehyde selectivity was increased and isomerization was decreased. Solvated sodium ions in the layer silicate hectorite were readily exchanged by Rh(diene)(PPh3)2+ rhodium complexes. 1A7 IR and X-ray studies confirmed this result. The supported catalyst systems were active for hydroformylation of 1- hexene, but extensive rhodium desorption occurred under hydroformylation conditions. It was clear that the complex which desorbs from the negatively charged silicate surfaces could not be cationic. Further studies of the effects of acid (HClOu) and base (NEt ) on the activity of the homo- 3 geneous catalysts showed that the reactive intermediate was a neutral monohydride complex which was in equilibrium with inactive rhodium dihydride complex, H2Rh(CO)x(PPh3)2+. Therefore, the neutral intermediate was readily desorbed from the silicate surfaces. Positively charged rhodium complex analogs RhH(CO)x- (PPh3)2 suitable for intercalation was prepared first by reaction of Ph2P(CH2)2P+Ph2(CH2Ph) with rhodium(I) complexes such as [RhCl(diene)]2, Rh(diene)+ where diene = COD or NBD under hydroformylation conditions. These catalysts were active both in homogeneous and intercalated systems. In all of supported catalysts n/b aldehyde selectivity in- creased and isomerization of l-hexene to 2-hexene decreased relative to homogeneous solution. 31P NMR studies confirmed that the coordinating ability of the positively charged ligand (P-P+) in solution is similar to triphenyl phosphine (PPh3). Also, C1Rh(CO)(S)2— (P-P+)2, S = acetone was isolated as one of the major re- active intermediates during the course of hydroformylation reaction. REFERENCES 10. 11. 12. 13. l“. 15. REFERENCES A. Nakamura, M. Tsutsur, "Principles and Applications of Homogeneous Catalysis", John Wiley & Sons, N.Y., 1980, pp. 1-9, and references therein. K. F. Purcell and J. C. Kotz, Inorganic Chemistny, p. 963, and references therein. (a) G. w. Parshall, J. Mol. Catal., 0, 203-270 (1978). ’ (b) F. R. Hartley, CHEMTECH, 686 (1980). P. Pino, F. Piacenti, M. Bianchi, I. Inwender and P. Pino (Eds), "Organic Syntheses Via Metal Carbonyls", Wiley-Interscience, New York, 1977, Vol. 2, p. A3. R. gowler, H. Connor, R. A. Baehl, CHEMTECH, 722, 197 . R. L. Pruett, J. A. Smith, U.S. Patent, 3,917,661 (1975), Chem. Abs., @3, 30033 (1976). C. S. Cronan, Chem. Eng., §fl_(26), 109 (1977). F. E. Paulik, Catal. Rev., 6, 09 (1972). H. Hohenschutz, N. VonKutepow, W. Hummele, Hydrocarbon Process., 35 (11), 1A1 (1966). J. F. Roth; J. H. Craddork, A. Hershman; F. E. Paulik, CEMTECH., l, 600 (1971). J. Smidt, W. Hafner, R. Jira, R. Sieber, J. Sedlmeier, A. Sabel, Angew. Chem. Int. Ed., 1, 80 (1962). S. A. Miller, Chem. Process. Eng. 50(6), 63 (1969). J. A. Blay, U.S. Patent, 3,983,208 (1976); Chem. Abs., §_6_. 20025 (1977). E. Welton, German Patent, 2,027,280 (1970); Chem. bS°3 13: 63983 (1971)- __ ZDQ N. Winnick, German Patent, 1,91U,572 (1969): Chem. 95-: 1E, 59773 (1970). PC) 1A8 16. 17. 18. 19. 20. 21. 22. 23. 2A. 25. 26. 27. 28. 29. (11), G. H. R. B. 139 . Towle, R. H. Balwin, Hydrocarbon Process, 99 1A9 (196A). . Lowery, A. Aguilo, Hydrocarbon Process., 5 103 (197A). Twig, Chem. Ind., A76 (1966). Stobaugh, V. A. Calarco, R. A. Morris, L. W. Stroud, Hydrocarbon Process., 23, 99 (1973). G. Wilke, Angew Chem. Int. Ed., 3’ 105 (1963). T. Alderson, E. L. Jenner, R. V. Lindsey, J. Am. Chem. Soc., 91. S638 (1965). Dupont, Chem. Eng. New (April 26) 30, 1971. F. J. Bellringer, C. E. Hollis, Hydrocarbon Process, 31, 127 (1968). M. W. Abs. Farlow, U. S. Patent, 2,518,608 (1950), Chem. 3;, 639 b (1951). ““ G. Alexmills, CATAL-Rev. SCI. ENG. 99(1), 69 (1976). E. L. “79, (a) (b) (a) (b) (e) (a) (b) (C) Muetterties and J. Stein, Chem. Rev., V. 19(6) (1979), and references therein. R. L. Pruett, Ann. N.Y. Acad. Sci., 395, 239 (1977). ~ E. L. Mutterties, Science, 196, 839 (1977). B. L. Hoymore and J. A. Ibers, J. Am. Chem. Soc., 26. 3325 (1974). C. D. Meyer and R. Eisenberg, J. Am. Chem. Soc., 29. 136a (1976). S. Bhaduri and B. F. G. Johnson, Trans. Met. Chem., 9, 156 (1978). L. Marko and B. Heil, CATAL. REV. SCI. ENG., §(2). 269 (1973). W. S. Knowles, M. J. Sabacky, B. D. Vineyard, Adv. Chem. Ser., 132, 275 (197A). B. D. Vineyard, W. S. Knowels, M. J. Sabacky, G. L. Bachman and D. J. Weinkauff, J. Am. Chem. Soc., 99, 59A6 (1977). 30. 31. 32. 33- 3A. 150 (a) F. A. Cotton, G. Wilkinson, "Advanced Inorganic Chemistry", John Wiley & Sons, 1980, pp. 163- 165, 26A-265. (b) G. A. Cotton, et al. J. C. S. Dalton, 181, 1978. (c) D. E. Fenton, Chem. Soc. Rev., g, 325 (1977). (a) J. Manassen (1973), In "Catalysis, Progress in Research" (F. Basolo and R. L. Burwell, Jr., eds), pp. 177-188, Plenum, New York. (b) J. C. Bailer, Jr., Catal. Rev. Sci. Eng. 19(1), 17 (1974). (c) J. P. Candlin and H. Thomas, Adv. Chem. Ser., 132, 212 (197A). (a) F. R. Hartley and P. N. Vezey, Advan. Organometal. Chem., $1, 189 (1977). ‘ (b) Z. M. Michalska, D. E. Webster, Chemtech, 9, ll7_(l975)- (c) R. L. Pruett, Advances in Organometal. Chem., £1, 1-57, Academic Press, New York, San Francisco, London, 1979- C. N. Satterfield "Heterogeneous Catalysis in Prac- tice", p. 5-7, copyright 1980. (a) D. G. H. Ballard, Advan. Catal. 39, 269 (1973). (b) L. L. Murrell "Advanced Materials in Catalysis" (Ed. J. J. Burton and R. L. Garton, p. 239-265 and references therein (1977). (c) M. S. Scurrell "Catalysis", p. 215-2Al and references therein. (d) See Reference (31b), (32a). (e) J. M. Basset and A. K. Smith, "Fundamental Homo- geneous Catalysis", ed. by M. Tsutsui and R. Ugo. Plenum Press, N.Y., p. 69, and references there— in. (f) M. S. Scurrel, Platinum Metals Rev., 21, 92 1977. (g) R. H. Grubbs, Chemtech, 512 (1977). (h) Yu. I. Yermakov, Cat. Rev. Sci. Eng., 13, 77 (1976). 35- 36. 37. 38. 39. A0. A1. A2. A3. AA. A5. A6. A7. 151 (i) D. D. Whitehurst, Chemtech, AA (1980). (J) B. C. Gates and J. Lieto, Chemtech, 195 (1980). J. Villadsen and H. Liveberg, Catal. Rev. Sci. Eng. 11: 203 (1978). R. R. Rony and J. F. Roth, J. M01. Catal., 1. 13 (1975/76). (a) R. H. Grubbs and R. C. Kroll, J. Am. Chem. Soc., 9;, 3062 (1971). (b) R. H. Grubbs, C. Gibbons, R. C. Kroll and C. Brubaker, J. Am. Chem. Soc., 95, 2373 (1973). (a) C. U. Pittman, L. R. Smith and R. M. Hanes, 1. Am. Chem. Soc., 91, 17A2 (1975). (b) C. U. Pittman and L. R. Smith, ibid, 91, 17A9 (1975). G. Braca, G. Sbrana, C. Carlini and F. Ciardelli, "Catalysis, Homogeneous and Heterogeneous", Delmon and Jannes, 307 (1975) and references therein. M. Graziani, G. Strukul, M. Bonivento, F. Pina, E. Cerniaand N. Palladino, ibid., p. 33. R. F. Batchelder, B. C. Gates and F. P. Kuijpers, "Proceedings of the Sixth International Congress on Catalysis, 1976", Ed. G. C. Bond, P. B. Wells and F. C. Tompkins, Thé'Chemical Society, London 1, A99 (1977) C. U. Pittman, Jr., B. T. Kim, and W. M. Douglas, “0: 590 (1975), J. Org, Chem. W. Dumont, J. C. Poulin, T. P. Dang and H. B. Kagan, J. Am. Chem. Soc., 99, 8295 (1973). T. H. Kim and H. F. Rase, Ind. and En . Chem., (Pro- duct Res. and Development), 15, 2A9 (1976). S. Jacobson, W. Clementz, H. Hiramoto and C. U. Pitt- man, J. Mol. Cata1,, 1, 73 (1975/76). C. U. Pittman, Jr. and R. M. Hanes,.J. Am. Chem. Soc., 99, 5A02 (1976). W. O. Haag and D. D. Whitehurst, "Proceedings 5th International Congress on Catalysis 1972". North Hol- land, Amsterdam, 1, A65 (1973). A8. A9. 50. 51. 52. 53. 5A. 55. 56. 57. 58. 59. 152 A. Gupta, A. Rembaum and H. Gray, Organomet. Poly [Symp], 1977 Pub. 1978, P- 155. F. Hojabri, J. Appl. ChemgiiBiotchnol., fig, 362 (1976). I. Dietzman, D. Tomanova and J. Hetflejs, Coll. Czech. Chem. Comm. 39, 123 (197A). M. Mejstrikova, R. Reriche and M. Kraus, ibid, _9, 135 (197A). C. U. Pittman, Jr., S. K. Wuu, and S. E. Jacobson, J. Catal., 33, 87 (1976). 7‘ (a) I. V. Howell, R. D. Hancock, R. C. Pitketly and P. J. Robinson, "Catalysis Homogeneous and Hetero- geneous", Delmon and Jannes, ed., pp. 3A9 (1975). Pitketly and P. J. Robinson, J. Organomet. Chem., 91. 189 (1975). (0) Ibid, §_7_, 203 (1975). (d) K. G. Allum, R. 0. Hancock, I. V. Howell, R. C. Pitketly and P. J. Robinson, J. Catalysis, 99, 322 (1976). (e) T. J. Pinnavaia, J. G. S. Lee and M. Abedini, "Silylated Surfaces", D. Leyden, ed., Morden and Breach, N.Y., pp. 333 (1980). (h) K. G. Allum, R. D. Hancock, 8. M. Kenzi, R. C. ' R. Jackson, J. Raddlesden, D. J. Thompson and R. Whelan, J. Organomet. Chem., 125, 57 (1977). M. Capka and J. Hetfle, Coll. Czech. Chem. Comm., 99, 15A (197A). K. G. Allum, R. D. Hancock, I. V. Howell, T. E. Lester, S. McKenzie, R. C. Pitketly and P. J. Robinson, J. Organomet. Chem., 107, 393 (1976). L. L. Murrel, A. A. Oswald and R. L. Hartherink, Preprints, Div. Petr. Chem. National Meeting, Am. Chem. Soc., Chicago, p. 1226 (1977). F. R. W. P. Wild, G. Gubitosa and H. H. Brintzinger, J. Organomet. Chem., 1A8, 73 (1978). K. G. Allum, R. D. Hancock, S. McKenzie and P. C. Piketly, Proc. 5th Int. Congress Catal. 1972, A77 (1973). 61. 62. 63. 6A. 65. 66. 57. 68. 69. 70. 71. 72. 73. 7A. 153 K. G. Allum, R. D. Hancock, I. V. Howell, T. E. Lester, S. McKenzie, R. C. Pitkethy and R. J. Robinson, J; Catal. 33, 331 (1976). D. G. H. Ballard, Adv. Cat., 23, 263 (1973) and references therein. '— Y. I. Yermakov, Cat. Rev., 13, 77 (1976) and references therein. —‘ V. A. Zakharov and Y. I. Yermakov, Catal. Rev., Sci. Eng., 19 (1), 67 (1979)- N. Takahashi, I. Okura, and T. Keii, J. Am. Chem. Soc., 91, 7A89 (1975). Ref. 30(a), p. 51A-515 and references therein. M. A. Boersma, Advanced Materials in Catalysis, p. 67-99 (1977) (ed. by J. J. Burton and R. L. Garten). E. Mantovani, N. Palladiano, A. Zanobi, J. of M01. Catal., 3, 285 (1977/78). (a) I. E. Maxwell, R. S. Dowin s and S. A. J. Van- Langer, J. of Catal., 61, 85 (1980). (b) Ibid, §;, A93 (1980). S. Tsuruya, H. Miyamoto, T. Sakae and M. Masai, J. of Cat., 63, 260 (1980). T. J. Pinnavaia, R. Raythatha, J. G. S. Lee, L. J. Hollaran, and J. F. Hoffman, J. Am. Chem. Soc., 101, 6891 (1979). T. J. Pinnavaia and R. Rahthatha, submitted for pub- lication. T. J. Pinnavaia and Han Min Chang, unpublished. (a) R. E. Grim, "Clay Mineralogy", 2nd ed., McGraw- Hill, New York, 1968, pp. 77-92. (b) R. M. Barrer, FRS "Zeolites and Clay Minerals as Sorbents and Molecular Sieves", Academic Press, 1978, pp. AO7-A86 and references therein. (a) D. M. Clementz, T. J. Pinnavaia, M. M. Mortland, J. Phys. Chem., 11, 196 (1973). 7A. 75. 76. 77. 78. 79. 80. 81. 82. 83. 8A. 15A (b) M. McBride, T. J. Pinnavaia, M. M. Mortland, Am. Mineralogist, 6g, 66 (1975). (c) T. J. Pinnavaia, "Magnetic Resonance in Colloid and Interface Science", ACS Symp. Ser., 3A, H-A. Resing, C. G. Wade, eds., 1976, p. 9A. S. I. Zones M. R. Palmer, J. G. Palmer, J. M. Doemeny, G. N. Schrauzer, J. Am. Chem. Soc., 100, 2113 (1978). B. K. G. Theng, "The Chemistry of Clay-Organic Re- actions", John Wiley & Sons, Inc. New York, NY, 197A. D. B. Fenn, M. M. Mortland and T. J. Pinnavaia, Clays and Clay Minerals, 21,315 (1973). W. H. Quayl and T. J. Pinnavaia, Inorg; Chem., l8, 28A0 (1979). (a) H. E. Doner, M. M. Mortland, Science, 166, 1A06 (1969). (b) M. M. Mortland, T. J. Pinnavaia, Nature Phys. Sci, 229, 75 (1971). (c) T. J. Pinnavaia, M. M. Mortland, J. Phys. Chem., 15, 3957 (1971)- (d) D. B. Penn, M. M. Mortland, T. J. Pinnavaia, Clays, Clay Minerals 21, 315 (1973). (a) T. Endo, M. M. Mortland and T. J. Pinnavaia, Clays and Clay Minerals, 28, 105 (1980). (b) T. Endo, M. M. Mortland and T. J. Pinnavaia, Clays and Clay Minerals, 29 (2), 153 (1981). Otto Roelen, Ger. Pat. 8A 95A8 (1938); Chem. Zentr., 1953, 927. E. J. Wickson, H. P. Dengler, No. 11, 69 (1972) "Hydrocarbon Process". B. Conils, "New Synthesis with Carbon Monoxide", (ed. J. Falbe), N. Y. (1980),11, p. 1 and references therein. (a) F. E. Paulik, 6(1)z A9-8A (1972)., Catal. Rev. (b) R. Lai and E. Ucciani, Advances in Chemistry Series, 132, 1— 26 (197A). 8A. 85. 86. 87. 88. 90. 91. (c) (d) (e) (f) (g) 155 A. T. Jurewicz, L. D. Rollmann and D. D. White- hurst, ibid, pp. 2A0-251. P. Pino, G. Consiglio, C. Bott eghi and C. Salmon, 9696, pp. 295-323. P. Pino, F.Piacenti and M. Bianchi, V. 2, pp. 93-231, (1977) "Organic Synthesis via Metal Car- bonyls", (ed. by I. Wender and P. Pino). Roy L. Pruett, V. 17, pp. 1-60 (1979), Advances in Organometallic Chemistry. See footnote cited in 83 pp. 1-225. G. Y. Hsu and M. Orchin, J. Am. Chem. Soc., 97, 3553 (1975). G. Sontos, B. Heil and L. Marko, Ann. N.Y. Acad. Sci., 3.32, (a) (b) (c) (d) (e) (f) (g) (a) (b) A7 (197“). D. Evans, G. Yagupsky, G. Wilkinson, J. Chem. Soc (A), 2660 (1968). “————— G. Yauupsky, C. K. Brown, G. Wilkinson, J. Chem. Soc., Chem. Commun. 12AA (1969). Ibid, 1392 (1970). D. E. Moris, H. B. Tinker, 9, 55A (1972). A. J. Draesmith, R. Whymann, J. Chem. Soc., 362 (1973). R. Whymann, J. Organomet. Chem., 66, C23-C25, 197“, 81, 97 (197A), 9“, 303 (1975)- P. Calderazzo, Angew Chem., 69, 305 (1977). F. Piacenti, et al., J. Organomet. Chem., 39, 257 (1970). J. P. Grima, F. Choplin, G. Kaufman, J. Organo- met. Chem. , 129, 221 (1977). T. Kitmura, T. Joh, J. Organomet. Chem., 66, 235 (197A). P. L. Ragg, ICI (Ltd), DE-As 2000 829 (1972). (a) (b) R. C. Ryan, C. U. Pittman, J. P. O'Connor, J. Am. Chem. Soc., 99, 1986 (1977). C. U. Pittman, R. C. Ryan, CHEMTECH (9), 170 (1978). 92. 93- 9M. 95. 96. 97. 98. 99. 100. 102. 103. 104. 105. 156 C. U. Pittman, G. 0. Evans, CHEMTECH, Sept. 1973, p. 560. C. U. Pittman, Jr., S. E. Jacobson, H. Hiramoto, J. Am. Chem. Soc., 91, 477A (1975). M. 0. Farrell, C. H. VanDyke, L. J. Boucher, S. J. Metlin, J. Organomet. Chem., 169, 199 (1979). R. L. Burwell, CHEMTECH, June, (197“) 370. R. D. Hancock, I. V. Howell, R. C. Pitkethy and P. J. Robinson, "Catalysis:Heterogeneous and Homogeneous", (ed. by, B. Delmon and G. Janes) (1975) pp. 361-371. 0. Johnson, ibid, p. A97. G. C. Bond, P. B. Wells F. C. Tompkins, The Chemical Society London, V. 1, A88 (1977). E. H. Homeier, UOP, Inc. U.S. h,070,AO3 (1978). J. S. Yoo, U. _S. 3, 9H0, HA7 (1976), Atlantic Richfield Co. J. P. Friedrich, Ind. Eng. Chem. , Prod. Res. Div., 17, 205 (1978) P. R. Rony and J. F. Roth, J. of M01. Catal., l, 13 (1975/76). (a) L. A. Gerritsen, A. VanMeerkerk, M. H. Vreug- denhil, J. J. F. Scholten, J. Mol. Catal., 9, (d) 139 (1980). (b) L. A. Gerritsen, J. M. Herman, W. Klut and J. J. F. Scholten, J. Mol. Catal. ,9, 157 (1980) (c) L A. Gerritsen, J. M. Herman, W. Klut and J. J F. Scholten, J. Mol. Catal., g, 2A1 (1980). (d) L. A. Gerritsen, W. Klut, M. H. Vreugdenhil, an nd J. J. F. Scholten, J. Mol. Catal. , g, 257 (1980). L. J. A. Gerritsen, W. Klut, M. H. Vreugdenhil and J F Scholten, J. Mol. Catal., 9, 265 (1980). R. Uson, L. A. Oro, C. Claver, M. A. Garrolda, {. Mol. Catal., 9, 231 (1978). 106. 107. 108. 109. 110. 111. 112. 113. 11H. 115. 115. 117. 118. 119. 120. 121. 157 C. Ercolani, J. V. Qua%liano, L. M. Vallariano, Inczsi_flbim1_AcLa. 3. 21 (1969)- R. C. Taylor, R. A. Kolodny, Inorg. Nucl. Chem. Letters, 1, 1063 (1971). (a) D. Berglund, D. W. Meek, J. Am. Chem. Soc., 963' 518, (1968). (b) D. Berglund, D. W. Meek, Inorg. Chem., 6, 2602 (1969). R. D. Bertrand, D. A. Allison, J. G. Verkade, J. Am. Chem. Soc., 2g, 71 (1970). (a) R. L. Keiter, D. P. Shah, Inorg. Chem., 1;, 191 (1972). (b) R. L. Keiter, L. W. Cary, J. Am. Chem. Soc., 9_, 9232 (1972). R. C. Taylor, R. L. Keiter, L. W. Carry, Inorg. Chem. Li, 1928 (197“). J. A. Connor, J. P. Day, E. M. Jones, G. K. McEwen, J. Chem. Soc. (D), 347 (1973). D. D. Traficante, J. A. Sims, M. Mulcahy, J. Magn. Res., £9, H8“ (197A). J. Chatt and L. M. Venanzi, J. Chem. Soc. (A), M735 (1975). H. C. Volger, M. M. P. Guasbeek, H. Hogeveen and K. Varieze, Inorg. Chim. Acta., 9, 1&5 (1969). H. C. Volger and H. Hogveen, Rec. Trav. Chim., B6, 1066 (1967). ‘— R. R. Schrock and J. A. Osborn, J. Am. Chem. Soc., 23, 2397 (1971). P. Uguagliati, G. Deganello, L. Busetto and U. Belluco, Inorg. Chem., 1625 (1969). M. Green, T. A. Kuc and S. H. Taylor, J. Chem. Soc. (A), 233” (1971). H. G. Horn and K. Sommer, Spectrochim. Acta. A., g1, 10H9 (1971). (a) D. Evans, J. A. Osborn and G. Wilkinson, 6. Chem. Soc. (A), 3133 (1968). 121. 122. 123. 12“. 125. 126. 127. 128. 129. 130. 131. 132. 133. 158 (b) C. K. Brown and G. Wilkinson, J. Chem. Soc. (A), 2753 (1970). J. Peone and L. Vaska, Angew. Chem., 66, 511 (1971). R. H. Crabtree and H. Felkin, J. Mol. Catal., 9, 75 (1979). See Reference 8u(f), pp. 29-32. (a) U. Mayer, V. Gutmann and W. Gerger, Monat. fur Chem., 106, 1235 (1975). (b) V. Gutmann and R. Schmid, Coord. Chem. Rev., l3, 253 (197”). . Grimbolt, J. P. Bonnelle, C. Vaccher, A. Movtreux, . Petit, J. Mol. Catal., 9, 357 (1980). Chem. Soc. C, “88 (1966). J F F. Piacenti, P. Pino, R. Lazzaroni and M. Bianchi, J F. Asinger and O. Berg, Chem. Ber., 66, MAS (1955). (a) B. Fell, W. Rupilius, and F. Asinger, Tetrahed- ron Lett., 3261 (1968). (b) F. Asing, B. Fell, and W. Rugilius, Ind. Eng; Chem., Prod. Res. Develop., _, 21A (1969). E. D. Becker, "High Resolution NMR - Theory and Chem- icaé Applications" Academic Press, New York, Ch. 7 (l9 9). . T. Quayle, Ph.D. Thesis, Michigan State University, 1979. T. H. Brown and P. J. Green, J.A.C.S., 99, 2359 (1970). P. Uguagliati, G. Deganell, L. Busetto and U. Belluco, Inor . Chem., 8, 1625 (1969).