A COMPARISON OF THE RATES OF METHYLATION OF MERCURY(II) SPECIES IN AQUATIC MEDIA BY VARIOUS ORGANOTIN AND ORGANO-SILICON MOIETIES

Metals can be methylated in environmental aqueous media by a variety of organotin and organosilicon compounds. Main group metals and metalloids were surveyed for the identification of species that can either donate or accept methyl groups. The methylation of mercury(II) by trimethyltin cation was found to be a bimolecular reaction, the reaction rate of which decreased with increasing chloride concentration. Kinetic investigations using NMR techniques showed that the most important pairs of reactants were (CH3)3Sn+ + HgCl2, (CH3)3SnCl + HgCl2, and (CH3)3SnCl + HgCl-3. Sodium 2,2,3,3-tetradeutero-3-(trimethylsilyl)propionate (TSP) and sodium 2,2-dimethyl-2-silapentane-5-sulfonate (DSS) were found to methylate mercury(II). Organylsilatranes were found to transfer their organic groups readily to mercury(II) to produce organomercury compounds.