Synthesis, crystal structures, and urease inhibitory activity of Schiff base copper and nickel complexes

Abstract

Urease inhibitors can inhibit the decomposition rate of urea, and decrease the air pollution caused by ammonia. In this paper, three new copper(II) and nickel(II) complexes [Cu2L2(μ1,1-N3)2] (1), [Cu(HL)2]Br2 (2), and [Ni3L2(DMF)2(μ2—η1:η1-CH3COO)2(μ1,1-N3)2] (3), where L = 5-bromo-2-(((2-isopropylamino)ethyl)imino)methyl)phenolate, HL = 5-bromo-2-(((2-iso­propylammonio)ethyl)imino) methyl)phenolate are synthesized and characterized. The complexes are characterized by elemental analyses, IR, UV-Vis spectra, molar conductivity, and single crystal X-ray diffraction. The X-ray analysis indicates that Cu atoms in complexes 1 and 2 are in square pyramidal and square planar coordination, respectively. The Ni atoms in complex 3 are in octahedral coordination. The molecules of the complexes are linked through hydrogen bonds and π⋯π interactions. The inhibitory effects of the complexes on jack bean urease are studied, which show that the copper complexes have a strong inhibitory effect on urease.