Fluoride Respectively

https://theses.gla.ac.uk/ Theses Digitisation: https://www.gla.ac.uk/myglasgow/research/enlighten/theses/digitisation/ This is a digitised version of the original print thesis. Copyright and moral rights for this work are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This work cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Enlighten: Theses https://theses.gla.ac.uk/ [email protected] THE PREPARATION AND lUGLEAE MAGNETIC RESONANCE SPECTRA OF SOME VOLATILE FLUORINE COMPOUNDS by Jo to Michaol Winfield A thesis submitted to the University of Glasgow in fulfilment of the requirements for the Degree of Doctor of Philosophy. August 1964 ProQuest Number: 10647846 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uesL ProQuest 10647846 Published by ProQuest LLO (2017). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLO. ProQuest LLO. 789 East Eisenhower Parkway P.Q. Box 1346 Ann Arbor, Ml 48106- 1346 ABSTRACT The preparation of alkyl, phenyl and pentafluoro- phenyl derivatives of non-metallie fluorides has been attempted by reaction of a fluoride with a tetraorgano- tin.. A smooth reaction occurred only with fluorides that are strong Lewis acids. In other cases decomposi tion of the organotin molecule occurred under the conditions necessary to initiate the reaction. The reactions are discussed in relation to the chemistry of organotin compounds and the Lewis acidic- or basic character of the fluorides. The reactions of bis(trifluoromethyl)peroxide with some metal carbonyls have been carried out with a view to preparing trifluoromethoxy derivatives of metal carbonyls* In most cases bis(trifluoromethyl)peroxide reacted as a fluorinating agent; where other products were formed, they were very unstable. The nuclear magnetic; resonance spectra of some polychloropolyfluorobenzenes and fluorobenzenes contain methyl, carboxylic ester and nitro substituents are described. and Spin-spin coupling constants in these compounds are characteristic of the ring positions that the atoms occupy* This has enabled the structures of the compounds to be determined where 19 they were unknown. The effect on the F chemical shif of chlorine and fluorine atoms in different ring positions has been determined and empirical relationshi 19 found for the change in the P chemical shift with a chlorine for fluorine substitution in the ortho, meta and para ring positions. Using these relationships the structures of some chlorofluorophenols have been determined. The effect that a ring substituent in a given 19 position has on the F chemical shift is modified by adjacent substituents. This has been shown also for methyl, carboxylic ester and nitro substituents. Both steric and electronic factors determine a substituent’s 19 effect on the F chemical shift. 19 The F nuclear magnetic resonance spectra of the three isomers of the ly4-dichlorotetrafluorobutadiene, the two isomers of 4-dichlorotetrafluorocyclobutene-l and of two chloropolyfluorocarbcn derivatives of ôulphu hexafiuoride are described. The chemical shifts and coupling constants found are discussed in relation to current theories. The coupling constants of the 1 9 4“'dic?iIorot8trafluorobutadiene isomers have permitted some observations on their conformations to be madOo Coloured solutions of tungsten hexafiuoride in several organic donor solvents and of molybdenimi hexafiuoride and tantalum pentafluoride in hexafluoro- 19 benzene have been prepared. The P nuclear magnetic resonance spectra of the molybdenum and tungsten hexafiuoride solutions show the presence of hexafluorid molecules, inferring that the colours are due to charge transfer interaction. However the effect of such 19 interaction upon the 'P chemical shift of the hexa fiuoride is small- Evidence for the presence of lower valency states of tungsten was found in diethyl ether solutions. AOÎCNOWLEBOMENTS The work described in this thesis was carried out in the Chemistry Department of the University of Strathclyde, Glasgow (formerly the Royal College of Science and Technology). I wish to express my thanks to my supervisor Dr. Do V/o Ao Sharp for his advice and encouragement during this work and to Dr. P. Bladon for instruction in the method of Nuclear Magnetic Resonance spectroscopy Mr. To Boyle is thanked for technical assistanceo This work has benefited as a result of many discussions with the staff and research students of the Chemistry Department and also from the help and encouragement of my wife. The award of a D.S.I.R. Research Studentship for the period I961«64 is gratefully acknowledged. August 1964 University of Strathclyde ABSTHAOT The preparation of phenyl and pentafliioro^ phenyl derivatives of noa-metalllc fluorides has been attempted by réaction of a fluor id© with a tetmorgano- tin.. A smooth reaction oeeurred only with fluorides that are strong Lewis acids. In other cases decomposi tion of the organotin molecule occurred under the conditions necessary to Initiate the reaction. The reactions are discussed in relation to the chemistry of organotin compounds and the Lewis aeidie or basic character of the fluor*ides. The reactions' of bis(trifluoromethyl)peroxide with some metal carbonyls have been carried out with a view to preparing trifluorometho:^ derivatives of metal carbonyls* In most cases bis (trifluoromethyl) perosclde reacted as a fluorinating agent; where other products were formed^ they were very unstable. The nuclear magnetie resonance spectra of some polychloropolyfluorobenzenes and fluorobenzenes containing methylg earb03^1io ester and nitro substituents are described. and Spin-spin coupling constants in these compounds are characteristic of the ring positions that the atoms ooeupy. This has enabled the structures of the cmipounda to he determined where IQ they were unknown. The effect on the F chemical shift of chlorine and fluorine atoms in different ring positions has been determined and empirical relationships found for the change in the chemical shift with a chlorine for fluorine aubstitution in the ortho, meta and para ring positions. Using these relationships the structures of some chlorofluorophenols have been deteminedo The effect that a ring substituent in a given 1 q position has on the F chemical shift is modified by adjacent substituents. This has been shorm also for methyl, carboxylic ester and nitro substituents. Both steric and electronic factors determine a substituent’s effect on the chemical shift. 19 The F nuclear magnetic resonance spectra of the three isomers of the 1 ^4-diohlorotetraf1uorobutadiene, the two isomers of 3 g4-dichlorotetrafluoroGyelobutene-I and of two chloropolyfluorocarbon derivatives of sulphur hexafiuoride are described. The chemical shifts and coupling constants found are discussed in relation to current theories. The coupling constants of the l 0 4-diehlorotetrafluorobutadiene isomers have permitted some observations on their confomations to be made. Cbloured solutions of tungsten hexafluorid© in several organic donor solvents and of molybdenum hexafiuoride and tantalum pentafluoride in hexafluoro»* 19 benzene have been prepared. Tii© f nuclear magnetic resonance spectra of the molybdenum and tungsten hexafiuoride solutions show the presence of hexafiuoride molecules, inferring that the colours are due to charge transfer interaction. However the effect of such IQ interaction upon the F chemical shift of the hexa fiuoride is smallo Evidence for the presence of lower valency states of tungsten was found in dietliyl ether solutionso CONTENTS Pag© Introduction 1 Chapter 1 The Reactions of Non-metallle Fluorides with Orgainotin Compounds 5 Experimental 31 Chapter 2 The Reactions of Bis(trifluoromethyl) peroxide with some Metal Carbonyls 52 Experimental 63 Chapter 3 The Nuclear Magnetic Resonance Spectra of some Fluorobensen© Derivatives 71 Experimental 105 Description of Spectra 108 Chapter 4 The Nuclear Magnetic Resonance Spectra of some Aliphatic FIuorocarbon Derivatives 138 Experimental 161 Description of Spectra 162 Chapter 5 Some Molecular Complexes of Transition ^tal Fluorides 182 Experimental 200 Appendix Apparatus used in the Course of the Work 206 References 215 INTRODUCTION The chemistry of fluorine is very extensive as it is the most chemically reactive element knoim. It will combine directly with the majority of elements either at room or at elevated temperature. The great reactivity of fluorine is due in part to the low energy of the P-P bond (37.7 i 0.2 kcal,mole“^). This is far lower than the bond energies of the other halogens and has been attributed to repulsion between the non^bonding electrons of the F atomso Also the other halogens have vacant d orbitals available for multiple bonding. Fluorine is also the most electronegative

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