STUDIES ON THE INTERACTION OF SELENITE AND SELENIUM WITH SULFUR DONORS .1. 2-MERCAPTOETHANOL

Raman spectroscopy and proton and Se-77 NMR have been used to show tha t selenous acid reacts with 2-mercaptoethanol (HOC2H4SH), according to Ganther's reaction (H.E. Ganther, Biochemistry, 7, 2898 (1968)). H2Se O3 + 4HOC(2)H(4)SH --> HOC2H4SSC2H4OH + HOC2H4SSeSC2H4OH + 3H(2)O The bis(hydroxyethylthio)selenide decomposes readily in strongly acidic an d moderately basic solution to selenium and disulfide, HOC2H4SSeSC2H4O H --> Se + HOC2H4SSC2H4OH Selenium dissolves in excess hydroxyethylmer captide to give the catenated anion, HOC2H4SSe- HOC2H4S- + Se = HOC2H4 SSe- Air oxidation of this equilibrium mixture yields disulfide and se lenium. Formation of the hydroxyethylthioselenide is endothermic (Delt a H = 0.66 +/- 0.02 kJ mol(-1)).