Preparation and infrared characterisation of some new organotin carboxylate polymers

Abstract

There has been considerable interest in recent years in the synthesis and structure of monoorganotin polymers [l-3] containing carboxylate groups. Cleavage of the tin-carbon bond by carboxylic acids under rigorous conditions has so far been applied for the synthesis of these polymers. In this paper we wish to report the preparation of a few new polymers using a relatively convenient route involving cleavage reactions of tin-carbon bonds in triorganotin carboxylates (R$nOCOR where R = phenyl, Ph; Propyl, Pr; Butyl, Bu; Cyclohexyl and R’ = H, CH2, CH,CH,) with mercury(I1) salts such as mercuric halides and acetate. In a typical reaction run, to a solution of triorganotin carboxylate in ether or benzene, a solution of mercuric salt (1: 1) in ether was added dropwise with stirring. Although a white precipitate was formed immediately, the mixture was stirred for a further 4 hours at room temperature to ensure complete reaction. The volatiles were removed and the residual solid was extracted with hot benzene which left a white insoluble polymeric material (infusible up to 360 ‘C, except for the formate; -0COH group containing polymers which decomposed at about 270 “C). The benzene extract on fractional crystallisation afforded triorganotin halide and organomercuric halide. By contrast, reaction of mercuric acetate with triphenyltin acetate afforded diphenyl mercury and a tin polymer. The products obtained from these reactions were characterised by analytical and spectral data. Considering the stoichiometry, the following equations may be proposed to account for the reaction products: