CATALYTIC-OXIDATION OF 2-ELECTRON DONORS BY DINUCLEAR COPPER(II), NICKEL(II) AND COBALT(II) COMPLEXES AND EPOXIDATION OF OLEFINS USING IRON(III) COMPLEXES

Dinuclear copper(II), nickel(II), cobalt(II) and iron(III) complexes d erived from the Schiff base ligands obtained from the condensation of 3,3'-dimethyl-4,4'-diamino-biphenyl and pyridine-2-aldehyde and mononu clear iron(III) complexes of Schiff bases from substituted anilines an d pyridine-2-aldehyde have been synthesised. Conductivity measurements on dilute solutions revealed that the dinuclear complexes are 1:4 ele ctrolytes while the mononuclear complexes are 1:2 electrolytes. The ge ometry of the complexes is assigned based on spectral and magnetic sus ceptibility values. Catalytic activity of these complexes for the oxid ation of two-electron donors such as 3,5-di-t-butylcatechol (3,5-DTBC) and ascorbic acid is examined. Dinuclear iron(III) complexes show gre ater activity than the mononuclear complexes for the epoxidation of ol efins, namely cyclohexene and styrene using iodosyl benzene as oxygen source.