Synthesis, characterization and biological studies of cobalt(II), nickel(II), copper(II) and zinc(II) complexes of vanillin-4-methyl-4-phenyl-3-thiosemicarbazone

Abstract

Complexes of vanillin-4-methyl-4-phenyl-3-thiosemicarbazone with cobalt(II), nickel((II), copper(II) and zinc(II) metal ions were synthesized and characterized by elemental analysis, molar conductance, magnetic moment, infrared spectra, electronic spectra, 1 H and 13 C NMR, mass spectrum and thermal analysis. The low molar conductance values indicate that all the complexes are non-electrolytes. Spectral studies indicate that the ligand act in a tridentate manner coordinating with the metal ion through sulphur, oxygen and nitrogen atoms. Based on magnetic moment measurements, spectral studies and thermal analysis, suitable geometry was proposed for the metal complexes. Thermal stability of the complexes was ascertained on the basis of thermo gravimetric analysis and the lattice parameters, space group and grain size of the ligand and complexes were determined by using powder XRD measurements. Surface morphology of ligand and complexes were studied using SEM analysis. Antimicrobial studies were carried out against gram-positive, gram-negative bacteria and two fungal pathogens.

The Coordination chemistry and cyclic voltammetry exploration of Cu(II), Co(II), Ni(II) and Zn(II) complexes of novel (E)-3,4-dichloro-N-(2-(1-(pyridin-2-yl)ethylidene)hydrazine-1-carbonothioyl) benzamide ligand

“…This is may be attributable to the high electropositivity of metal ion which withdraw electron density from the multiple bonds like C=N and C=S towards it and then reduce the multiple bond characteristic as well as the effect of the resonance conjugation between the aryl and the C=O groups considers main factor to present the long wavelength. These results seem to be consistent with other research, which found thiosemicarbazone derivative of Ni(II), Co(II) and Cu(II) compounds adopted octahedral geometry [49][50][51] and the other that revealed the square planar geometry of these metal derivatives [52][53].…”

A heterocyclic N'-(4-(diethylamino)-2-hydroxybenzylidene)-4-oxopiperidine-1-carbohydrazide Schiff base ligand and its metal complexes: Synthesis, structural characterization, thermal behavior, fluorescence properties, and biological activities

“…The ligand chromophores transition of π → π* and n → π* group in the UV region. The complex is found to be diamagnetic, as expected for the d 10 system, which may suggest the tetrahedral geometry around the Zn(II) ion [21].…”

Synthesis and antioxidant activities of new nickel(II) complexes derived from 4-benzy- loxysalicylidene-S-methyl/propyl thiosemicarbazones

“…In the UV-Vis spectra of thiosemicarbazones the band observed at 240 nm is attributed to π→π* transition belonging to substitute benzene group. n→π* transitions associated with the imine group of thiosemicarbazone moiety are recorded at 294 and 305 nm [33,34]. These bands were also detected at 240-244 nm and 294-306 nm in the spectra of the complexes.…”