Diimine complexes of iron(II), cobalt(II) and copper(II); Synthesis, spectral and electrochemical study

Tris chelate complexes, [M(L-L)(3)](2+) (M = Fe2+, Co2+, Cu2+; L-L = Ph-N=C(Ph)C(Ph)=N-Ph) have been synthesized and characterized by elemental analyses, IR and visible spectral data. Their oxidation reduction characteristics have been investigated by cyclic voltammetry technique. All these complexes exhibit in-tense MLCT absorptions in the visible region. When compared to that in corresponding bipyridine complexes the positions of these bands are found significantly shifted. Their cyclic voltammogram show a reversible one electron oxidation wave and an irreversible two electron reduction wave. The spectral and electrochemical properties of the complexes have been interpreted in terms of pi acid behaviour of the Ligand.