Catalytic oxidation of two-electron donors by dinuclear copper(II), nickel(II) and cobalt(II) complexes and epoxidation of olefins using iron(III) complexes

Abstract

Dinuclear copper(II), nickel(II), cobalt(II) and iron(III) complexes derived from the Schiff base ligands obtained from the condensation of 3,3′-dimethyl-4,4′-diaminobiphenyl and pyridine-2-aldehyde and mononuclear iron(III) complexes of Schiff bases from substituted anilines and pyridine-2-aldehyde have been synthesised. Conductivity measurements on dilute solutions revealed that the dinuclear complexes are 1:4 electrolytes while the mononuclear complexes are 1:2 electrolytes. The geometry of the complexes is assigned based on spectral and magnetic susceptibility values. Catalytic activity of these complexes for the oxidation of two-electron donors such as 3,5-di-t-butylcatechol (3,5-DTBC) and ascorbic acid is examined. Dinuclear iron(III) complexes show greater activity than the mononuclear complexes for the epoxidation of olefins, namely cyclohexene and styrene using iodosyl benzene as oxygen source.