Oxidation of ethanol by cobalt, iron, and rhodium complexes

Abstract

Aerial oxidation of ethanol in the presence of an aromatic azo-compound and CoX₂(X = F, Cl, O₂CMe, or ClO₄) or iron(III) chloride gives a stoicheiometric amount of acetaldehyde with CoCl₂, Co[O₂CMe]₂ and FeCl₃ but no oxidation occurs with CoF₂ and Co[ClO₄]₂. Addition of nitrogen-donor ligands promotes the oxidising activity in CoF₂, and this effect is discussed and a mechanism is proposed for the oxidation. The cobalt(II) chloride–aromatic azo-compound combination effects slow catalytic oxidation of a potassium propionate–propanol mixture. Several rhodium comolexes which catalytically oxidise ethanol are reported, and 5% Rh–C dehydrogenates ethanol smoothly at its boiling point.