AN ABSTRACT OF THE THESIS OF Jeffrey Templeton Miller for the degree of Doctor of Philosophy in Chemistry presented on IA et)e07, /9816 Title:I.SYNTHESIS OF SUBSTITUTED CYCLOOCTATETR.AENIDE DIANIONS.LI. CYCLOHEPTADIENYL COMPLEXES OF THE d- AND f- TRANSITION ELEMENTS. III.REACTIONS OF CYCLOHEXANONE WITH METAL VAPORS Abstract approved: Redacted for Privacy Dr. Carroll W. De Kock I.Lithium alkyl and aryl monosubstituted cyclooctatetraenide dianions (LiCH-R; R = methyl, n- butyl, sec- butyl, tert- butyl, 287 phenyl and benzyl) were synthesized by the reaction of the appropri- ate organolithium reagent with cyclooctatetraenein diethyl ether or tetrahydrofuran.The reaction occurred cleanly and with good yield of lithium monosubstituted cyclooctatetraenide dianion at ambient or lower temperature for all organolithium reagents studied except tert-butyl-lithium. (TMEDA is needed as an activator for methyl- lithium. )Substituted cyclooctatetraenide dianions were character- ized by chemical reactions, i. e., oxidation,hydrolysis and deuter- olysis, as well as, preparation of organometallicderivatives, sub- stituted uranocenes. A two step mechanismfor the reaction is pro- posed which involves the addition of theorganolithium reagent to cyclooctatetraene followed by proton removal to yield the appropriate ten-Tr electron aromatic dianion. Several other alkyl organometallic compounds failed to produce mono substituted cyclooctatetraenide dianions on reactingwith cyclo- octatetraene.Lithium hexaalkyluranate(IV) complexes reacted with cyclooctatetraene to give uranocene in good yield along with high yields of coupled alkyl products. II.The addition of lithium cycloheptadienide (LiC7H8-R; R c hydrogen, methyl and n-butyl) to lanthanide and actinide chlorides results in the facile formation of unstable cycloheptatrienyl trianion- metal compounds. Characterization of the ten-Tr aromatic cyclohepta- trienyl trianion (C7H6-R-3)was made by identification of the organic products resulting from chemical reactions of the coordinated ligand, for example, hydrolysis, deuterolysis and oxidation, as well as, spectroscopic characterization(1HNMR) of paramagnetic uranium(IV) 1H compounds.Qualitative analysis of the paramagnetic NMR shifts are discussed based on the assumption thatmetal-ligand bond dis- tances and magnetic properties in cycloheptatrienyl-uranium(IV) com- pounds are similar to those of uranocene.Formation of the cyclo- heptatrienyl trianion is believed to occur by the loss of twomethylene protons from the metal coordinated cycloheptadienideion.The role of the lanthanide and acinide metal ions in cycloheptatrienyltrianion formation is discussed. III.Metal atom vapors of several d- and f-transition elements were cocondensed with cyclohexanone at-196°C.Radical reduction of cyclohexanone to bicyclohexy1-1, Pdiol, a pinacol, was observed for elements which are both highly electropositive and form strong metal oxygen bonds, for example, the early transition,lanthanide and actin- ide elements. High yields of aldol condensation products were pro- duced along with a small amount of bicyclohexylidene.Metal atoms .of the latter transition elements were much less reactive with cyclo- hexanone and did not yield a pinacol product. Titanium clusters were prepared by codepositing titanium atoms with a large excess of solvent.Titanium clusters were less reactive than titanium atoms toward cyclohexanone radical reduction reactions. High surface area titanium powders produced by solution techniques, yield pinacols when cyclohexanone reacts in excess andfurther deoxygenate pinacolic dianions to olefins under conditions oflimited stoichiometry. Nitrobenzene was deoxygenatively coupled to azoxybenzene and azobenzene by lanthanide and actinide metal atoms. I.Synthesis of Substituted Cyclooctatetraenide Dianions. U.Cycloheptadienyl Complexes of the d- and f-Transition Elements.III.Reactions of Cyclohexanone with Metal Vapors. by Jeffrey Templeton Miller A THESIS submitted to Oregon State University in partial fulfillment of the requirements for the degree of Doctor of Philosophy Completed June 1980 Commencement June 1981 APPROVED: Redacted for Privacy Associate Professor of Chemistry in charge of major Redacted for Privacy Chairman of Department of Chemistry Redacted for Privacy Dean of Graduate School Date thesis is presented June 27, 1980 Typed by Opal Grossnicklaus for Jeffrey Templeton Miller ACKNOWLEDGMENTS The completion of this manuscript is by no means the accom- plishment of a single individual.I am pleased to share credit for this thesis with Carroll De Kock, who throughout the last four years has provided direction, encouragement, enthusiasm and assistance which has contributed to my personal and professional development.I would also like to thank him for the friendship he has shown to me and my family. I would like to thank my wife and daughterfor. their love, sup- port, encouragement and sacrifice over the lastseveral years. I would also like to thank Susan Randall for her fine work in collecting the spectroscopic data on the many extremelydifficult and unstable samples. I am indebted to the National Science Foundation, theOregon State University Research Council and the ChemistryDepartment at O.S. U. for their financial support for this researchand my continuing education. TABLE OF CONTENTS Page I. SYNTHESIS OF SUBSTITUTED CYCLOOC TATETRAENIDE DIANIONS 1 INTRODUCTION 1 Metallation of Olefinic Hydrocarbons by Organolithium. Compounds 2 Addition of Organolithium Compounds to Carbon- Carbon Double Bonds 4 Previous Studies of Organolithium Compound.s with Cyclooctatetraene 8 RESULTS AND DISCUSSION 10 The Reaction of Cyclooctatetraene with Organolithium Compounds 10 The Reaction of Cyclooctatetraene with Lithium Hexaalkyl Uranate(IV) Complexes 17 CONCLUSIONS 19 EXPERIMENTAL 23 General Considerations 23 Synthetic Procedures 24 Preparation of n-Butylcyclooctatetraenide Dianion 24 n-Butylcyclooctatetraene 24 n- Butylcyclooctatriene and n- Butylcyclooctatriene-d2 25 1, P -Di-n- butyluranocene 25 Stoichiometry 26 Tert-Butyl-Lithium and Cyclooctatetraene 27 Lithium Hexabutyluranate(IV) plus Cyclooctatetraene 29 BIBLIOGRAPHY 31 II. CYCLOHEPTADIENYL COMPLEXES OF THE d- AND f- TRANSITION ELEMENTS 34 INTRODUC TION 34 Comparison of the Cycloheptadienide and Cyclopentadienide Anions 34 Cycloheptadienyl Compounds of the Transition Metals 40 page RESULTS AND DISCUSSION 45 Preparation of Lithium Cycloheptadienide 45 Bis (6- Methylcycloheptadienyl) Iron(II) 48 Reaction of Lithium Cyclopentadienide with Dichlorobiscycloheptadienyl Titanium(IV) 49 Reaction of Lithium Cycloheptadienide with Lanthanide and Actinide Chlorides 50 Cycloheptatrienyl Trianion Compounds of Zirconium 60 CONCLUSIONS 62 EXPERIMENTAL 68 General Considerations 68 Preparation of Cycloheptadienide Anions 68 1, 3 and 1, 4-Cycloheptadiene 69 Lithium n-Butylcycloheptatrienyl Trianion, Li C nBu 70 5 Bis(6-Mahyl h -Cycloheptadienyl) Iron(II) 70 Biscyc lope ntadienyl Titanium (III) Chloride 71 Formation and Characterization of the Cycloheptatrienyl Trianion 72 Hydrolysis 73 Oxidation 74 Alkylation 74 Preparation of a Zirconium Cycloheptatrienyl Trianion Compound 77 BIBLIOGRAPHY 79 III. REAC TIONS OF CYCLOHEXANONE WITH METAL VAPORS 82 INTRODUCTION 82 . Reductive Coupling of Carbonyl Compounds to Pinacols 82 Reductive Deoxygenation of Carbonyl Compounds to Dimeric Olefins 85 Reduction of Nitro Compounds by Transition Metal Compounds 91 RESULTS AND DISCUSSION 93 Metal Atom Cocondensation with Cyclohexanone 93 Cyclohexanone Reduction with Titanium Atom/ Solvent Clusters 98 Page Titanium Tetrachloride-Potassium Reduction of Cyclohexanone 102 Nitrobenzene Reduction by Metal Atoms 106 CONCLUSIONS 1 07 EXPERIMENTAL 112 Materials 112 General Procedure for Metal Atom Vapor Plus Cyclohexanone Cocondensation 113 General Procedure for Titanium Atom Vapor/ Solvent Plus Cyclohexanone Cocondensation 114 Cyclohexanone Reduction by Potassium Reduced Titanium Tetrachloride Metal Powders 115 Nitrobenzene-Metal Atom Reactions 115 Spectral Data 116 BIBLIOGRAPHY 119 LIST OF FIGURES Figure Page 1-1. Characterization of Substituted Cyclooctatetraenide Dianions 11 1-2. 2,7-Di-t-butyl-[4,2,01' 6]- bicyclo-octa-2,4 diene. 27 1-3. 6,7 -Di-t- butyl-1,3,5 -cyclooctatriene. 28 2-1. Cycloheptadienide Ion. 34 2-2. Hiickel, Molecular Orbital Energies for Cyclopenta- dienide and Cycloheptadienide Anions. 36 2-3. Calculated Htickel Electron Densities for the Cyclo- heptadienide and Cyclopentadienide Anions. 38 2-4. 13CNMR Shift (Tr -Electron Densities) for Cyclohepta- dienide and Cyclopentadienide Anions. 39 2-5. Chemical Characterization of Lanthanide and Actinide Cycloheptatrienyl Trianion Complexes. 51 1H 2-6. Dipolar Contribution to NMR Shift for C8H8-2. 57 1H NMR Shift for CH7-3. 57 2-7. Dipolar Contribution to 7 2-8. Molecular Orbital Model of theElectronic Structurefor 10 -Tr Aromatic - Uranium(IV) Compounds. 59 2 -9. Activation of Carbon-Hydrogen Acidity by Tr -Bond Overlap. 66 3-1. Mechanism for Pinacolic Dianion Formation. 84 3-2. Mechanism for Tungsten Reduction of Carbonyls to Olefins. 88 LIST OF TABLES Table pale 1-1. Reaction Data for Mono substituted Cyclooctatetra- enide Dianions. 13 1H 2-1, NMR for Ring Protons(U44Complexes). 56 2-2. Mass Spectral Parent Ion Fragmentation Pattern of Deuterolysis Products of CiHea C7H6-R-3, and C7H6-R" (R=H, n-Bu, Me). 75 3-1. Materials for Reductive Coupling of Cyclohexanone. 83 3-2. Materials for Carbonyl Reduction to Olefins. 86 3-3. Metal Properties. 94 3-4. Reaction Products of Cyclohexanone