Notes. Activation of dioxygen and catalytic oxidation of ethanol to acetaldehyde and hydrogen peroxide by copper(<scp>I</scp>) complexes containing 2,2′-bipyridyl and tertiary phosphine ligands

Abstract

Reactions of [Cu(bipy)Ll](bipy = 2,2′-bipyridyl; L = PPh3, PMePh2, PBun3, or PEt3) with O2 alone in dimethylformamide and SO2 plus O2 in dichloromethane lead to the formation of [Cu2(bipy)2(OH)2]l2 and precipitation of Cu[SO4]. The complex [Cu(bipy)Ll] catalyses the oxidation of ethanol by dioxygen to acetaldehyde and H2O2 in the presence of equimolar quantities of Na[OC2H5]. Added phosphine acts as a strong inhibitor and the catalytic decomposition of H2O2 by the complexes leads to their deactivation. A tentative reaction mechanism is discussed.