ELECTROCHEMICAL OXIDATION OF SILATRANES

Cyclic voltammetry and voltammetry on a rotating ring-disc electrode h ave been used for the electrochemical study of silylated cyclic deriva tives of triethanolamine-silatranes. Silatranes in acetonitrile on a g lassy carbon electrode undergo electro-oxidation at high potentials. T he process is diffusional and proceeds with one-electron transfer. Ele ctro-oxidation is irreversible at scan rates below 100 mV s-1, partial ly reversible at higher scan rates (v = 200, 500 mV s-1) and reversibl e at low temperatures (T < -10-degrees-C). The primary products of ele ctro-oxidation are cation radicals of relatively low stability. The pr ocess is coupled with chemical reactions, which are retarded at low te mperatures. The potentials of electro-oxidation are affected significa ntly by the electronic effects of substituents at the silicon atom. Th is leads to the conclusion that silatranes undergo electro-oxidation w ithout preceding cleavage of donor-acceptor bonding N --> Si.