Spectroscopic, magnetic, and electrochemical behavior of the copper(II) complex of carnosine.

Different physicochemical studies were undertaken with polycrystalline samples of the complex [Cu2(carnosine)2(H2O)2].2H2O. The infrared spectrum was discussed in comparison with that of free carnosine and on the basis of the known structural data. Magnetic susceptibility measurements were performed between 4.2 and 300 K, showing an effective magnetic moment of 1.79 BM. Both the electronic (reflectance) and ESR spectra were compatible with the existence of a dx2-y2 ground state. The axial reversed ESR spectrum could be explained on the basis of a very weak interdimeric coupling mechanism. The electrochemical behavior, investigated by cyclic voltammetry, shows that the complex possesses a very high redox stability. The possible SOD-like activity was tested using the NBT/superoxide reduction assay. The results show a negligible SOD activity.