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 (MPhT), 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 DPhT and TPhT were recovered in the combined DEE phase and 94% of the MPhT remained in the aqueous phase. The MPhT 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, DPhT, and TPhT was better than 99%. At -20 ^oC, all the fractionated phenyltin species were stable in the storing solution for at least 197 days. When these standards were stored at 4 ^oC or 22 ^oC, 4% to 6% of DPhT and TPhT degraded during 27 days. The degradation of DPhT and TPhT increased with the ionic strength and acidity of the storage solution.