SYNTHESIS AND STORAGE OF SINGLE PHENYLTIN COMPOUNDS SYNTHESIZED FROM ISOTOPICALLY ENRICHED TIN METAL

Abstract

A method combining liquid liquid extraction and chromatographic fractionation has been developed for the preparation of pure monophenyltin (MPT), diphenyltin (DPhT), and triphenyltin (TPhT), synthesized from isotope enriched Sn-metal using phenylation of SnI4 in diethylether (DEE) followed by quenching with HBr and water. After two successive extractions of the aqueous HBr phase with DEE, more than 99% of the DPT and TPhT were recovered in the combined DEE phase and 94% of the MPT remained in the aqueous phase. The MPT in the aqueous phase was extracted into dichloromethane. The organic phases were vaporised and the PhTs were re-dissolved in MeOH/water/acetic acid/sodium acetate (59/30/6/8, v/v/v/w), which was also used as storing solution. Aliquots of the two solutions containing either DPhT and TPhT or MPhT were injected into a silica based C18 column for isolating and purifying single species. The yield of the purification of MPhT, DPT, and TPht was better than 99%. At -20 °C, all the fractionated phenyltin species were stable in the storing solution for at least 197 days. When these standards were stored at 4 °C or 22°C, 4% to 6% of DPhT and TPhT degraded during 27 days. The degradation of DPT and TPht increased with the ionic strength and acidity of the storage solution.