Synthesis, characterization, crystal structures, and urease inhibition of copper(II) and Zinc(II) complexes derived from benzohydrazones

A new copper(II) complex [Cu(L¹)(NCS)(CH₃OH)] (1) and a new zinc(II) complex [ZnCl₂(HL²)] · CH₃OH (2), derived from 4-bromo-N’-(pyridin-2-ylmethylene)benzohydrazide (HL¹) and 4-methoxy-N’-(pyridin-2-ylmethylene)benzohy-drazide (HL²), were prepared and characterized by elemental analysis, IR and UV-Vis spectroscopy and single crystal X-ray diffraction. The hydrazone HL¹ coordinates to the Cu atom in enolate form, while the hydrazone HL² coordinates to the Zn atom in carbonyl form. Single crystal structural analyses indicate that the hydrazones coordinate to the metal atoms through the pyridine N, imino N, and enolate/carbonyl O atoms. The Cu atom in complex 1 is in square pyramidal coordination, and the Zn atom in complex 2 is in trigonal-bipyramidal coordination. The inhibitory effects of the complexes on Jack bean urease were studied, which show that the copper complex has strong activity on urease.