Proton magnetic resonance studies of tris(trimethylsilyl)thallium

The intermolecular exchange of trimethylsilyl groups in tris(trimethylsilyl)thallium in a variety of solvents has been studied by n.m.r. spectroscopy, and values derived for the activation energy. The effect of trimethylamine in slowing the exchange has been studied, and evidence for the formation of an adduct Tl(SiMe3)3,NMe3 is given. Trimethylthallium has a marked catalytic effect on the exchange: evidence for mixed methyl–trimethylsilyl-thallium species is presented.