Electronic structure and spectroscopic properties of copper catecholate complexes with interligand charge-transfer behavior

The structural and spectroscopic properties of copper catecholate complexes with nitrogen ligands of the α- diimine type are studied by qualitative MO considerations. The characteristic feature of these donor acceptor systems is an interligand charge-transfer from the catecholate donor to the α-diimine acceptor site. The dependence of the interligand charge-transfer absorption band on the energies of the acceptor and the donor levels as well as on the solvent polarity is discussed.