Synthesis, structures, and urease inhibition of nickel(II), zinc(II), and cobalt(II) complexes with similar hydroxy-rich Schiff bases

Four new nickel(II), zinc(II), and cobalt(II) complexes, [Zn(L-1)(2)]center dot H2O (1), [Ni(L-1)(2)]center dot H2O (2), [Ni(L-2)(2)] (3), and [Co(L-3)(2)]center dot H2O (4), derived from hydroxy-rich Schiff bases 2-{[1-(5-chloro-2-hydroxyphenyl) methylidene] amino}-2-methylpropane-1,3-diol (HL1), 2-{[1-(2-hydroxy-3-methoxyphenyl) methylidene] amino}-2-ethylpropane-1,3-diol (HL2), and 2-{[1-(5-bromo-2-hydroxyphenyl) methylidene] amino}-2-methylpropane-1,3-diol (HL3) have been synthesized and characterized by elemental analyses, infrared spectroscopy, and single-crystal X-ray determination. Each metal in the complexes is six-coordinate in a distorted octahedral coordination. The Schiff bases coordinate to the metal atoms through the imino N, phenolate O, and one hydroxyl O. In the crystal structures of HL1 and the complexes, molecules are linked through intermolecular O-H center dot center dot center dot O hydrogen bonds, forming 1-D chains. The urease inhibitory activities of the compounds were evaluated and molecular docking study of the compounds with the Helicobacter pylori urease was performed.