Solvent Effect on the Proton Magnetic Resonance Spectra of Dimethyltin Dichloride, Trimethyltin Chloride and Trimethyllead Chloride

The chemical shifts of methyl protons (t(M–CH3) values) and the coupling constants between the methyl protons and the metal atom JM–CH3values for dimethyltin dichloride, trimethyltin chloride, and trimethyllead chloride have been measured in thirty-two organic solvents. From the relation between the t(M–CH3) and the JM–CH3values, the solvents used here have been classified into four groups. Carbon tetrachloride is representative of the first groups. The second group consists of usual polar organic solvents which can coordinate to the metal atom. The third consists of nitrobenzene, benzonitrile, pyridine, and its derivatives among the solvents studied here. The fourth consists of alkyl- or halogen-substituted aromatic solvents. The configurations of trimethyltin chloride in these solvents have been discussed on the basis of the J119Sn-CH3values and the intensity of the Sn–C symmetric stretching band relative to that of the asymmetric one. The effects of the temperature and the concentration of the solute on the t(Sn–CH3) and the J119Sn-CH3values of trimethyltin chloride have been examined in several solvents.