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To mimic the function of metallohydrolase, [M(bqad)Cl2] (M = Zn(II) (1), Co(II) (2), where bqad = N,N′-bis(2-quinolinylmethyl)amantadine), have been synthesized and characterized by elemental analysis, electronic absorption, IR, and single crystal X-ray diffraction. The structural analysis indicated that metal ions in1and2were coordinated by three nitrogens from bqad and two chlorides, resulting in a distorted trigonal bipyramidal geometry. Kinetic experiments for hydrolytic cleavage ofp-nitrophenyl acetate (pNA) catalyzed by1and2were performed at pH 7.50–10.00 and 298 K. The second-order rate constants (kobs) increased exponentially with variation of pH values. The Co(II) complex exhibited potent catalytic activity. [ABSTRACT FROM AUTHOR]

Two mixed-ligand Cu(II) complexes, [Cu(L 1 )(L 2 )](ClO 4 ) 2 ·H 2 O ( 1 ) and [Cu(L 1 )(L 3 )](ClO 4 ) 2 ·H 2 O·CH 3 OH ( 2 ) (L 1 = N , N ′-bis(2-pyridylmethyl)amantadine, L 2 = 5,5′-dimethy-2,2′-bipyridine, and L 3 = 1,10-phenanthroline), were synthesized and characterized by elemental analysis, UV–Vis, infrared spectra and single crystal X-ray diffraction. Copper ions in 1 and 2 behave the slightly distorted tetragonal pyramid configuration provided by CuN5 coordination set. Both complexes exhibit the quasi -reversible Cu(II)/Cu(I) one-electron redox waves determined by the cyclic voltammetry. Moreover, the frontier molecular orbital energies were obtained by DFT calculations with B3LYP method at LanL2DZ basis. Furthermore, by using NBT assay at pH 7.8, the superoxide dismutase (SOD)-like activity (IC 50 ) of 1 and 2 were measured to be 0.167 and 0.242 μM, respectively. The difference in SOD-like activities of two complexes could be ascribed to the rigidity of the auxiliary ligands. [ABSTRACT FROM AUTHOR]