DIRECT PRODUCTION OF BUTYLTIN CHLORIDES FROM A PAIRED ELECTROORGANIC SYNTHESIS

Butyltin chlorides were produced directly from butyl chloride and a ti n cathode in several undivided cell reactors with tetraethylammonium c hloride and acetonitrile solvent. The complex reaction chemistry was i nvestigated primarily in a small batch cell with a 1 cm2 planar cathod e. Current densities from cathodic linear potential sweeps at 1 mV s-1 were correlated successfully with current densities and butyltin prod ucts from potentiostatic experiments. Potential windows on product for mation and other major limiting reactions were thereby identified. Pro duct yield was shown to be strongly dependent on electrolyte gas condi tions, with yield decreasing as the reactor is increasingly deaerated. Use of the initial open circuit potential (i.o.c.p.) as an indicator of reaction gas conditions proved to be a convenient and reproducible technique. Under favourably oxidized conditions, current densities in the product formation potential region ranged from 66 mA cm-2 at -2.74 V vs SCE to 250 mA cm-2 at -2.98 V vs SCE which are considerably high er than previously reported current densities for this synthesis. Surp risingly, the aeration history of butyl chloride prior to synthesis ma y be an important factor in subsequent product yield.