CATALYTIC AND MAGNETIC-PROPERTIES OF A NEW SERIES OF BINUCLEAR COPPER(II) COMPLEXES

Binuclear copper(II) complexes of ligands derived from condensation of 2,6-diformyl-4-methylphenol with various aromatic mono- and diamines have been synthesized. Complexes derived from monoamines have the Cu2LCl3 composition and those from diamines have the Cu2L'Cl2 composition, where L and L' represent the ligands. Analytical data, conductance and spectral studies support these formulations. Cu2LCl3 complexes are chloro-bridged, as evidenced by two intense IR bands centred around 300 and 320 cm-1. Magnetic susceptibility measurements show that Cu2LCl3 complexes have low mu-eff values indicating magnetically interacting copper(II) centres and Cu2L'Cl2 complexes have non-interacting copper(II) centres. Cu2LCl3 complexes undergo single-step quasi-reversible reduction at -0.62 V vs SCE. Catalysis of Cu2LCl3 complexes for the oxidation of 3,5-di-t-butylcatechol (3,5-DTBC) and ascorbic acid by dioxygen is studied.