An Investigation Of The Preparation, Properties And Application Of Some 8-Carboalkoxyethyltin Compounds

The objective of this work has been to prepare and study a series of B -carboalkoxyethyltin halides and the corresponding carboxylate analogues. The chemistry of 8 -carboalkoxyethyltins and other related compounds is reviewed in Chapters 1 and 2 with particular reference to published work on the redistribution reactions of these compounds. Reaction routes to improve yields of tris(A-carboalkoxyethyl)tin halides were investigated. Redistribution reactions at a range of conditions to reduce the conversion rate to the tetraorganotin were particularly successful. An alternative synthesis using zinc chloride and stannous chloride with S-carboalkoxyethyltins was also studied. A series of transesterification reactions and hydrolysis reactions of f-car boalkoxyethyltins were undertaken to obtain more information about the mechanism. On the basis of spectroscopic data structural assignments are proposed for p-carboalkoxyethyltin halides. A related series tris($-carboalkoxyethyl)tin carboxylates was also synthesised and evaluated for biocidal function. In addition, the infra-red spectra of these saits showed interesting variations in %o20 absorptions enabling suggestions to be made about their stereochemistry. Vapour phase osmometry date, suggest that these tris@-carboalkoxyethyl)tin carboxylates are predominantly monomeric, but that this is dependent on the size of the alkyl groups. Both infra-red and Mossbauer date give evidence of electron back donation via the coordinating carbonyl group. This is explained in terms of electronic and steric contribution of the carboxylate group (RCO, The stereochemistry of tris(g -carboalkoxyethyl)tins is considered in the light of this dat. - ). The results of bacteriostatic and fungistatic evaluation of tris(#-carbobutoxyethyl)tin compounds are reported. Unlike simple triorganotin compounds, such as tributyltin acetate, many of the compounds evaluated proved to have low biological activity. The activities of two proved to be notable exceptions: tris(B-carbobutoxyethyl)tin glutamate sodium salt and the 2-ethylmercurithiosalicylate analogue, these are discussed and suggestions made to explain their activity.