Superoxidedismutase-mimetic Copper(II) complexes containing saccharinate and 4-aminopyridine/4-cyanopyridine

E. G. FERRER; BAEZA, N.; L. NASO; CASTELLANO, E. E.; O.E.PIRO; P. A. M. WILLIAMS

JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY

ELSEVIER GMBH

Año: 2010 vol. 24 p. 20 - 26

0946-672X

Two copper(II) complexes, [Cu(sac)2(4-cypy)2(H2O)], 1 and [Cu(sac)2(4-Ampy)2(H2O)], 2 (4-cypy: 4-cyanopyridine; 4-Ampy: 4-aminopyridine) were prepared. Physicochemical properties of the complexes were studied by spectroscopic (solution UV–vis, diffuse reflectance and IR) techniques. Structural X-ray diffraction data could be obtained only for [Cu(sac)2(4-cypy)2(H2O)] that it crystallized in the tetragonal space group P4cc with a=b=15.313(1), c=13.240(1) A (amstrong) , and Z=4 molecules per unit cell.The complex was cited on a crystallographic C2-axis with the Cu(II) ion in a square–pyramidal/environment, coordinated at the pyramid basis to the nitrogen atom of two saccharine anions/[d(Cu–N)=2.011(3) A (amstrong) and the pyridine N-atom of two 4-cyanopyridine ligands [d(Cu–N)=2.038(4) A (amstrong).The coordination was completed by a water molecule at the pyramid apex [d(Cu–Ow)=2.189(5) A (amstrong). Elemental and spectroscopic analyses revealed an O-saccharinate coordination mode for complex 2 and a square–pyramidal structure. Only complex 2 retained its structure in methanolic solution. However, both complexes were able to catalyze the dismutation of superoxide anion (O2) (pH 7.5) at micromolar concentrations. Therefore, these complexes behaved as useful SOD-mimetic compounds.