Insights into the role of zinc(II) sites in hydrolytic enzymes: study of the ZnII/X/(py)2CO (X=Cl−, N3−, SO42−; (py)2COdi-2-pyridyl ketone) reaction systems

A bioinorganic model approach for the investigation of substrate activation by zinc active sites in hydrolytic enzymes has been initiated. Several reaction schemes involving the substrate analogue di-2-pyridyl ketone, (py)2CO, and Zn(II) sources afforded the new complexes [ZnCl2{(py)2CO}](1), [ZnCl2{(py)2C(OMe)(OH)}](2), [Zn2Cl2{(py)2C(OMe)O}2](3), [Zn2(N3)2{(py)2C(OMe)O}2](4) and [Zn2(SO4)2{(py)2C(OMe)(OH)}2(MeOH)2](5), which have been characterized by single-crystal X-ray crystallography and spectroscopic techniques. The chemical and structural identity of the products depends on the solvent, the hydroxide concentration and the nature of the inorganic anion. The biological relevance of the prepared complexes is also discussed.