In presenting the dissertation as a partial fulfillment of the requirements for an advanced degree from the Georgia Institute of Technology, I agree that the Library of the Institute shall make it available for inspection and circulation in accordance with its regulations governing materials of this type. I agree that permission to copy from, or to publish from, this dissertation may be granted by the professor under whose direction it was written, or, in his absence, by the Dean of the Graduate Division when such copying or publication is solely for scholarly purposes and does not involve potential financial gain. It is under- stood that any copying from, or publication of, this dis- sertation which involves potential financial gain will not be allowed without written permission. 3/17/65 b PART ONE KINETICS OF THE DEUTERIUM EXCHANGE OF SUBSTITUTED METHYL ACETATES PART TWO EQUILIBRIUM IN THE ISOMERIZATION OF CERTAIN UNSATURATED COMPOUNDS A THESIS Presented to the Faculty of the Graduate Division by Louis Gates Mahone In Partial Fulfillment of the Requirements for the Degree Doctor of Philosophy in the School of Chemistry Georgia Institute of Technology October, 1966 PART ONE KINETICS OF THE DEUTERIUM EXCHANGE OF SUBSTITUTED METHYL ACETATES PART TWO EQUILIBRIUM IN THE ISOMERIZATION OF CERTAIN UNSATURATED COMPOUNDS Approved: Chairman zJ 1111111•■•••■■•■•■•■■ ••=1111.•■•■•6 Date approved by Chairman: )1 I 946 ii ACKNOWLEDGMENTS I wish to thank Dr. Jack Hine for his supervision of this work and for his many enlightening discussions of chemistry in general. Thanks are due also to Dr. Charles L. Liotta who assisted me in the latter phases of this work. I am grateful to Dr. Leon Zalkow for serving on the reading committee and to other faculty members and students who assisted me in various ways. I am grateful also to the Rayonier Corporation for financial assistance in the form of a fellowship. TABLE OF CONTENTS Page ACKNOWLEDGMENTS ii LIST OF TABLES LIST OF ILLUSTRATIONS viii SUMMARY PART ONE Chapter I. INTRODUCTION 2 II. EXPERIMENTAL RESULTS Chemicals 14 Instrumentation 19 Distillation Columns 19 Gas-Liquid Chromatography Instruments 19 Gas-Liquid Chromatography Columns 19 Titration Assembly and pH Meter 20 Infrared Instrument 20 Constant Temperature Bath 21 Boiling Point Determinations 21 Nuclear Magnetic Resonance Spectrometer 21 Quantitative Infrared Spectrometry 21 Titration of Base Solution 26 Treatment of Kinetic Data ...... .. • • e 0 • • • 27 General Kinetic Procedure 29 Investigation of Alkoxy Exchange for Methyl 3-Ethoxypropionate 30 Kinetics of the Drying of Methanol ...... 33 III. RESULTS AND DISCUSSION 36 Kinetic Results 36 Taft Correlation of Rate Constants 43 Electronegativity Correlation of Rates . ...... 50 IV. CONCLUSION 56 APPENDIX 57 ▪ • • iv LITERATURE CITED ...... • . • • 83 PART TWO Chapter I s INTRODUCTIONeoeooebo•o•Oe0o0•Goe•oe 87 II. EXPERIMENTAL RESULTS 101 Chemicals 101 Instrumentation 121 Equilibration of 3 -Methoxy -1 -methylthiopropene 122 Attempted Equiligration of trans-l-Methoxy-4- methylthio -2 -butene ........ ........ • • 123 Equilibration of the Methyl 4-Methylthiobutenoates . 127 Isomerization of Methyl 4 -Methoxycrotonate ..... 130 Isomerization of the 1-Methoxypropynes and Methoxyallene . 134 Attempted Equilibration of 3,3-Dimethoxy-l-propene and 1,1-Dimethoxy-l-propene . 136 III. RESULTS AND DISCUSSION . ........ 138 Syntheses of Olefins 138 Assignment of Structure 144 Nuclear Magnetic Resonance Spectroscopy 144 Infrared Spectrometery 149 Olefin Equilibria 151 IV. CONCLUSION 157 APPENDIX ............. 158 LITERATURE CITED 169 VITA 173 V LIST OF TABLES PART ONE Table Page 1. Boiling Point of Some Chemicals Used 18 2. Beer's Law for the 1960 cm -1 Band of Benzene in Carban Tetrachloride 24 3. Lambert's Law for the 1960 cm-1 Band of Benzene, 20 Volume Per Cent in Carban Tetrachloride 24 4. Summary of Deuterium Exchange Kinetic Data at 35 ° 58 5. Taft Correlation of Rate Constants for the Esters XYCHCO2CH3 59 6. Deuterium Exchange of Methyl Acetate--0.0972 M Sodium Methoxide 60 7. Deuterium Exchange of Methyl Acetate--0.0511 M Sodium Methoxide 61 8. Deuterium Exchange of Methyl Propionate-- 0.306 M Sodium Methoxide 62 9. Deuterium Exchange of Methyl Propionate-- 0.172 M Sodium Methoxide 63 10. Deuterium Exchange of Methyl Butyrate-- 0.579 M Sodium Methoxide 64 11. Deuterium Exchange of Methyl Butyrate-- 0.315 M Sodium Methoxide 65 12. Deuterium Exchange of Methyl 3-Methoxypropionate-- 0.0103 M Sodium Methoxide 66 13. Deuterium Exchange of Methyl 3-Methoxypropionate-- 0.00989 M Sodium Methoxide 67 14. Deuterium Exchange of Dimethyl Succinate--0.0431 M Sodium Methoxide 68 vi. Table Page 15. Deuterium Exchange of Dimethyl Succinate-- 0.0264 M Sodium Methoxide 69 16. Deuterium Exchange of Methyl Hydrocinnamate-- 0.203 M Sodium Methoxide 70 17. Deuterium Exchange of Methyl lydrocinnamate-- 0.284 M Sodium Methoxide 71 18. Deuterium Exchange of Methyl Methoxyacetate-- 0.1045 M Sodium Methoxide 72 19. Deuterium Exchange of Methyl Methoxyacetate-- 0.0882 M Sodium Methoxide 73 20. Deuterium Exchange of Methyl Dimethoxyacetate-- 0.644 M Sodium Methoxide 74 21. Deuterium Exchange of Methyl Dimethoxyacetate-- 0.634 M Sodium Methoxide 75 22. Deuterium Exchange of Methyl Fluoroacetate-- 0.0944 M Sodium Methoxide 76 23. Deuterium Exchange of Methyl Fluoroacetate -- 0.0922 M Sodium Methoxide 77 24. Deuterium Exchange of Methyl Difluoroacetate-- 0.362 M Sodium Methoxide 78 25. Deuterium Exchange of Methyl Difluoroacetate-- 0.560 M Sodium Methoxide 79 26. Deuterium Exchange of Methyl Phenylacetate-- 0.0043 M Sodium Methoxide 80 27. Rough Deuterium Exchange of Methyl 3- Ethoxypropionate. 81 28. Kinetics of the Drying of Methanol at 64.5° 82 29. Density of Sodium Methoxide-Methanol and Sodium Methoxide-Methanol-0-d Solutions at 250 82 vii PART TWO Table Page 1. Composition of Equilibrium Mixture for Unsaturated Sulfides, Sulfoxides, and Sulfones 89 2. Equilibration of the 1-Methoxy-3-methylthiopropenes at 50.0 ° in Dimethyl Sulfoxide 124 3. Analysis of the Isomerization of trans -1 -Methoxy- 4 -methylthio-2 -butene in Dimethyl Sulfoxide ..... 125 4. Equilibration of the Methyl 4 -Methylthiobutenoates 129 5. Isomerization of Methyl 4-Methoxycrotonate in tert-Butyl Alcohol at 20 ° and 35 ° 132 6. Equilibration of Methyl 4-Metgoxycrotonate in tert-Butyl Alcohol at 35.0 135 7. Nuclear Magnetic Resonance Data for Isomers of Methyl 4-Methoxycrotonate in 50 per cent Carbon Tetrachloride . 145 8. Nuclear Magnetic Resonance Data for Isomers of Methyl 4 -Methylthiocrotonate in 50 per cent Carbon Tetrachloride . 146 9. Nuclear Magnetic Resonance Data for cis and trans 1 -Methoxy- 3 -methylthiopropene in 50 per cent Carbon Tetrachloride . 147 10. Nuclear Magnetic Resonance Data for cis and trans 3 -Methoxy- -methylthiopropene in 50 per cent Carbon Tetrachloride . 148 11. Summary of Infrared Spectra of Olefins 150 12. Results of the Base-catalyzed Equilibrations of Certain Olefins 152 viii LIST OF ILLUSTRATIONS PART ONE Figure Page 1. Beef's and Lambert's Laws for the 1960 cm Band of Benzene in Carbon Tetrachloride 25 2. Kinetics of the oDeuterium Exchange of Dimethyl Succinate at 35 with a Sodium Methoxide Concentration of 0.0431 M 31 3. Plot of Hypothetical Deuterium Exchange Data Imposing a Kinetic Isotope Effect of Ten 41 -* 4. Taft Plot of a + o vs. Log k for the Esters X Y — 44 XYCHCO2CH3 5. Taft Plot of Monosubstituted Acetates of the Type XYCHCO2CH3 46 6. Correlation of Electronegativity and Rate for the Esters XYCHCO2CH3 52 PART TWO Figure Page 1. Infrared Spectrum of cis-3-Methoxy-l- methylthiopropene 159 2. Infrared Spectrum of trans-3-Methoxy-1- methylthiopropene 160 3. Infrared Spectrum of cis-1 -Methoxy-3- methylthiopropene 161 4. Infrared Spectrum of trans-1-Methoxy-3- methylthio-l-propene 162 5. Infrared Spectrum of trans-1-Methoxy-4- methylthio-2-butenoate 163 ix Figure Page 6. Infrared Spectrum of Methyl cis-4-Methoxy- 3-butenoate ..... ... ........ 164 7. Infrared Spectrum of Methyl 4-Methylthio- crotonate 165 8. Infrared Spectrum of Methyl cis -4-Methylthio- 3-butenoate 166 9. Infrared Spectrum of Methyl trans -4 -Methylthio - 3-butenoate 167 10. Nuclear Magnetic Resonance Spectrum of trans -1 - Methoxy -4 -methylthio -2 -butene in Carbon Tetrachloride 168 SUMMARY PART ONE According to the Pauling equation defining electronegativity the energy of a carbon-X bond in a saturated compound can be expressed as 2 BEC-X = 1/2 (BE + BE ) + 23(Xx - X6) C-C X- ( where BE's are the bond energies (in kcal/mole) of the bonds denoted by subscripts and X's are electronegativities. If the electronegativity of carbon stand in the order C sp > C sp 2 > C sp3 as has been reported, the C-X bond energy should be affected by the hybridization of this carbon in such a way that when X is highly electronegative the bond energies should stand in the order C -x > C 2-X > C -X. There are data that sp 3 sp sp suggests that fluoroolefins are less stable than their saturated ana- logues, however, there are other factors which complicate interpretation of this data. The energetics of reactions involving a change in the hybrid- ization of a carbon atom bound to X should be affected by the electro- negativity of X. Thus L,H for the transformation of C sp3 -X to C sp2-X should contain a term due to the enthalpy of rehybridization. E up - BEc = 1/2 ( 2 -C - ) B C 2-X Sp 3-X C sp sp 2 BBC sp 3-Csp 3 up 2 2 + 23(Xc 2 - 2X6 2Xx - X6 3 + 2X6 3Xx) sp sp sp 11 If the same transformation is considered in which X is replaced by Y, an analogous equation can be written; furthermore, the difference,pRx is simply stated in terms of the differences in electronegativity Xy Xx and Xcsp2 - Xcsp3. Nix Pay - - — = 46(X6 sp2 X6 sp3)(Xx - Xy) In as far as entropy changes are independent of the nature of the sub- stituents,&N.H =ziPF, and this equation becomes a linear free energy relationship which may be applied to equilibria and kinetic processes.