p-Nitrophenyl acetate hydrolysis promoted by Zn(II) and Co(II) complexes with the tripodal ligand of N,N′-bis(2-quinolinylmethyl)amantadine

AbstractTo 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 in 1 and 2 were coordinated by three nitrogens from bqad and two chlorides, resulting in a distorted trigonal bipyramidal geometry. Kinetic experiments for hydrolytic cleavage of p-nitrophenyl acetate (pNA) catalyzed by 1 and 2 were 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.