Syntheses, characterizations, crystal structures, antibacterial and SOD-like activities of nickel(II) and copper(II) complexes with 2-((Z)-(4-methoxyphenylimino) methyl)-4,6-dichlorophenol

摘要

Three mononuclear nickel(II) and copper(II) complexes, [Ni(L)(2) (py)(2)] (1), [Ni(L)(2) (DMF)(H2O)] (2), and [Cu(L)(2)] (3), where HL = 2-((Z)-(4-methoxyphenylimino) methyl)-4,6-dichlorophenol, py = pyridine and DMF = N, N-dimethylformamide, have been synthesized and their structures determined by single crystal X-ray analysis. Complexes 1-3 crystallized in the monoclinic system of the space groups C2/ c, P2(t/n), and P2(t/c), respectively. The crystal structures of 1 and 2 present an octahedral geometry at the metal center and 3 shows a squareplanar geometry. The FT-IR spectra, UV-vis spectra, and magnetic susceptibility measurements agree with the observed crystal structures. EPR spectra indicate a d(x2-y2) ground state (g(||) g(perpendicular to) 2.0023 and A || A.) for 3 at RT and LNT. The results of simultaneous TG-DTA analyses of 1 and 3 showed the final degradation products are NiO for 1 and CuO for 3. The Schiff base (HL) behaves as monobasic bidentate ligand possessing N and O donor atoms. Electrochemical properties for the complexes are similar and involve two irreversible redox processes. Complex 3 exhibits the ability to inhibit jack bean urease, although its Schiff base has no ability to inhibit urease. Complex 1 exhibits more active scavenging effects against O 2-than HL, 2 and 3 under the same conditions. Antibacterial screening activities of these complexes were also investigated.