Synthesis, structure and SOD-like activity of a ternary Cu(II) complex with 1,10-phenanthroline and L-valinate

The ternary Cu(II) complex with 1,10-phenanthroline (phen) and L-valinate (L-Val) has been synthesized and investigated by elemental analysis, molar conductivity, UV/vis, IR, TG-DTG, and X-ray diffraction methods. The complex crystallizes in the triclinic space group P1 with two molecules in a unit cell of dimensions, a=7.157(2) angstrom, b=11.967(4) angstrom, c=12.249(4) angstrom, alpha=68.290(4)degrees, beta=77.813(5)degrees, gamma=83.490(5)degrees, V=0.952.0(5) nm angstrom(3), R-1=0.0297, and wR(2)=0.0396. The crystal contains two crystallographically independent [Cu(H2O)(L-Val)(phen)](+)subunits Cu1 and Cu2, having a distorted square-pyramidal geometry with the same coordinated atoms around each copper center, the base plane being occupied by two nitrogen atoms of one phen, the amino nitrogen atom and one carboxylate oxygen atom from each independent L-Val moiety, and one water oxygen at an axial position. The SOD-like activity of the complex has been measured by means of modified nitroblue tetrazolium (NBT) photoreduction, and the IC50 value (the concentration of the complex which causes the 50% inhibition of NBT reduction) of the complex for disproportionation of (O) over bar2(circle) is 2.48x10(-7) M. The experimental results show that the complex is a potent superoxide dismutase mimic. CCDC: 267641.