Mécanisme général de réduction sur électrode de mercure des composés organostanniques aliphatiques R 2SnX 2 en milieu hydroalcoolique

Abstract

A general reduction mechanism for the aliphatic disubstituted compounds R 2SnX 2 with R=CH 3, C 2H 5, C 4H 9, t-C 4H 9, CH 2CH 2COOEt, in water-alcohol or methanol-lithium chloride media can be proposed after the study of the electrochemical reduction of 3,3′-(dibromostannio) diethylpropionate and chronocoulometric measurements. Except for the t-butyl derivatives in water-alcohol mixtures, the first step needs two electrons; dialkyltin which is formed polymerises or reacts with the depolarizer and gives the dimer (R 2SnX) 2. A second two-electron step can be observed. It seems that all the differences between the compounds investigated depend on the interactions between mercury and the reduction product, they are functions of the R group, the solvent and the ligand X. A discussion of these effects is given.