Electrochemical reduction of selenium in aprotic solvents: Application to the selective electrosynthesis of dialkyl selenides and/or diselenides

Abstract

Grey elemental Se x can be reduced electrochemically to Se 2− 2 in aprotic media (DMF, CH 3CN, THF). The electrochemical reduction occurs beyond −0.8 V vs. SCE on platinum and glassy carbon electrodes and −1.1 V on mercury. When the catholyte contains an alkyl halide, symmetrical dialkyl selenides and diselenides are competitively obtained. From the cyclic voltammetric behaviour of these compounds, it has been possible to define conditions which promote the formation of diselenides at the expense of selenides. Diselenides are preferentially generated on solid electrodes, at potentials close to −0.8 V, whereas selenides are obtained on mercury.