Spectrochemical properties of noncubical transition metal complexes in solution. XII. Angular overlap studies of salicylideneethylenediamine Cu(II) complex in various solvents

As a part of our general interest in the UV-Vis spectroscopy of multidentat e mixed-donor ligands, the (salicylideneethylenediamine)Cu(II) complex has been prepared and characterized by elemental analyses, solubility in common solvents, molar conductivities, and ultraviolet (UV), and visible (Vis) sp ectroscopy. The combined results of spectrophotometric measurements and EPR spectra, as well as known the X-ray structure for solids, were used to det ermine the structure of the investigated complex in solutions. The spectra of [Cu(salen)] (H(2)salen = salicylideneethylenediamine), were measured in various solvents at room temperature, resolved by Gaussian analysis, and an gular overlap model (AOM) treated in C-2v, symmetry. Because of over-parame trization problems, the bis(salicylaldehyde)Cu(II) complex has been charact erized and AOM treated. The results of this have been used for AOM studies of [Cu(salen)]. The effect of the solvents upon the sigma- and pi -bonding ligand abilities is discussed.