The trialkyltinderivatives of difunctional organic reagents such as thioglycol, dycolic acid, thioglycolic acid and so on and the trimethylmetal (M = Si, Ge, Sn) derivatives of thioglycol were prepared, and their thermal properties were investigated. A novel disproportionation reaction was found for some trimethyltin derivatives, which gave tetramethyltin and dimethyltin derivatives. Bis(trimethyltin)