Nickel (II) and cobalt (II) complexes with bidentate nitrogen-sulfur donor pyrazole derivative ligands: Syntheses, characterization, X-ray structure, electrochemical studies, and antibacterial activity

摘要

The synthesis, characterization, antibacterial activity and cyclic voltammetry of bidentate N,S donor pyrazole derivative ligands abbreviated as Na(EtNCSPz) (1), Na(PhNCSPz) (2), Na(PhNCSPz(me2)) (3), Na (PhNCSPz(me3)) (4) and their metal complexes with Ni(II) and Co(II) metal ions are reported, where Pz = pyrazole, Pz(me2) = 3,5-dimethylpyrazole and Pz(me3) = 3,4,5-trimethylpyrazole. All of the synthesized ligands and complexes have been characterized by physicochemical and spectroscopic methods and the crystal structures of [Ni(EtNCSPz)(2)] (1a) and [Ni(PhNCSPz(Me3))(2)] (4a) have been determined by X-ray diffraction analysis. The X-ray crystal structure of both the complexes describe a square planar coordination geometry. The electrochemical studies show that the synthesized complex is an electrochemically active species, furthermore, substitution electron donating groups on the ligands shift the reduction and oxidation potentials to negative values. Antibacterial activity results indicate these complexes possess high activity against gram-positive and gram-negative bacteria compare to the free ligands. (C) 2020 Elsevier Ltd. All rights reserved.