REACTIVITY OF THE TRIPODAL TRITHIOL 1,1,1-TRIS-(MERCAPTOMETHYL)ETHANETOWARD METHYL-MERCURY AND ETHYL-MERCURY HALIDES

The reaction of the tripod-like trithiol MeC(CH2SH)3 with MeHgI or EtH gCl in organic solutions, in presence of a base such as pyridine or tr iethylamine, allows the isolation of the trimetallic derivatives MeC(C H2SHgR)3 (R = Me or Et). An X-ray structure determination for the meth ylmercury complex has been carried out. Crystal data: monoclinic, spac e group P2(1)/a, a = 11.892(9), b = 18.621(2), c = 13.932(2) angstrom, beta = 90.95(3)degrees and Z = 8. The structure has been solved by th ree-dimensional Patterson and Fourier syntheses and refined by least s quares to a conventional R value of 0.036. The complex can be essentia lly described as an aggregate of three, virtually independent. linear two-co-ordinated methylmercury thiolates. However H-1 and C-13-{H-1} N MR spectra have shown that the trend of the reaction of methylmercury iodide with the trithiol, in pyridine solution, is quite different fro m that of the corresponding reaction with a related monothiol such as propane-1-thiol. This discrepancy has been ascribed to the potential c helating ability of the tripodal thiol, which should allow the formati on of intermediate chelated species, in which the metal atom has co-or dination numbers greater than two.