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

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

JOURNAL OF TRACE ELEMENTS IN MEDICINE AND BIOLOGY

Elsevier

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. Physiochemical properties of the complexes were studied by spectroscopic (solution UV–vis, diffuse reflectance and IR) techniques. Structural X-ray diffraction data could only be obtained for [Cu(sac)2(4-cypy)2(H2O)]. It crystallizes in the tetragonal space group P4cc with a=b=15.313(1), c=13.240(1) Å, and Z=4 molecules per unit cell. The complex is sited on a crystallographic C2 axis with the Cu(II) ion in a square pyramid environment, coordinated at the pyramid basis to the nitrogen atom of two saccharine anions [d(Cu-N)=2.011(3) Å] and the pyridine N–atom of two 4-cyanopyridine ligands [d(Cu-N)= 2.038(4) Å]. The coordination is completed by a water molecule at the pyramid apex [d(Cu-Ow)= 2.189(5) Å]. Elemental and spectroscopic analysis revealed an O-saccharinate coordination mode for complex 2 and a square pyramidal structure. Only complex 2 retains 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 represent useful SOD mimetic compounds.