SPECTROSCOPIC STUDIES ON MIXED-LIGAND COPPER(II) COMPLEXES

Mixed copper(II) complexes, Cu(bzyoxb)(diam)X (where bzyoxb = benzyl-( 2-oxobutanoat) diam = N,N,N',N'-tetramethylethylenediamine (tmen) and N-methyl-1,4-diazacycloheptane (medach), and X = ClO4-, Cl- and CH3CO2 - (OAc-)), have been prepared. Their structures and properties were ch aracterized by elemental analysis, UV-Vis, IR and Far IR spectroscopy and magnetic measurements. The square planar complexes were only obtai ned in presence of perchlorate anion, whereas the five coordinated com plexes were obtained for both Cl- and OAc- counter-anions. The d-d abs orption bands of perchlorate complexes were found to be linearly corre lated with the donor number of solvents or coordinating anions. The re sults are discussed in terms of the extended donor-acceptor concept.