Antioxidant potential and secondary reactivity of bis $\{$diphenyl(2-pyridyl)phosphino$\}$copper(II) complex

Copper-based complexes with the general formulas [Cu(L) 2 " role="presentation"> 2 2 _{2} ]Cl 2 " role="presentation"> 2 2 _{2} ( 1 ) and [Cu 2 " role="presentation"> 2 2 _{2} L 2 " role="presentation"> 2 2 _{2} ( μ 2 " role="presentation"> μ 2 μ 2 \mu_{2} -L) μ 2 − " role="presentation"> μ 2 − μ 2 − \mu_{2-} Cl 2 " role="presentation"> 2 2 _{2} ] ( 2 ) and a mixed-ligand anionic complex [Cu(L) 2 " role="presentation"> 2 2 _{2} dedtc][LCl] ( 3b ), where L = diphenyl(2-pyridyl)phosphine and dedtc = diethyldithiocarbamate, were synthesized and structurally characterized. X-ray analysis revealed that the coordination environment around the copper atom in complexes 1-3 is distorted tetrahedral. In monomeric complexes 1 and 3b both diphenyl(2-pyridyl) phosphine ligands are monodentate and are coordinated through the P-atom. In complex 3b two phosphine ligands are attached to copper through the P-atom. The third phosphine ligand acts as a bridged ligand, coordinated to the metal centers through the P-atom and N-atom. Complexes 1 and 3b were tested for radical scavenging activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) as a free radical. A prominent color change after mixing the solution of complex 1 and DPPH was observed, indicating the efficiency of the compound as antioxidant.