Carboxy ester hydrolysis promoted by two new bimetallic macrocyclic complexes. Synthesis, characterization and catalytic activity

摘要

A dinuclear macrocyclic ligand containing [12]aneN3 and its two transition metal complexes, [Zn2L(OAc)2](ClO4)2 (1) and [Cu2L(OAc)2](ClO4)2 (2) have been synthesized and characterized on the basis of elemental analyses, molar conductivities, ~1H-n.m.r, IR spectra, electronic spectra and thermal analysis. In addition, the studies on the hydrolysis of a caboxy ester, 4-nitrophenyl acetate (NA), promoted by the two complexes were also investigated. The experimental results indicated that the two complexes can efficiently catalyze hydrolysis of NA, and the k_(NA) for complexes (1) and (2) at pH 7.25, 25 °C, were calculated to be 4.46 x 10~(-2) and 4.21 x 10~(-2) m~(-1) s~(-1), respectively, which are better than those of the corresponding mononuclear complex in the same conditions.