Three 24-membered macrocyclic binuclear Cu(II) complexes for modeling Cu,Zn-SOD were synthesized by condensation reactions of 2,6-diacetylpyridine with 3-oxapentane-1,5-diamine, in which 2 metal centers linked via SCN-, N3- or imidazolate bridge. The former 2 complexes are new. They were characterized by several phys. methods, and the binding of imidazolate bridged complex with halides, azide and thiocyanate ions was studied by EPR and electronic spectra. Among them azide coordinates to Cu(II) as the 5th ligand in the axial position, and thiocyanate breaks the imidazolate bridge. These results are similar to the binding of SOD. As for the binding of halide ions, chloride displaces the imidazolate bridge and fluoride, bromide have no significant effect on the model complexes.

Key words: PYRIDINE P, COPPER COMPLEX, SUPEROXIDE DISMUTASE, PARAMAGNETIC RESONANCE, DINUCLEAR COMPLEX, ELECTRONIC SPECTROSCOPY