Synthesis, spectral, thermal, catalytic and biological studies of some transition metal complexes with unsymmetrical Schiff base ligand

Complexes of VOIV, Cr-III, Mn-III, Fe-III, Zr-IV, MoO2VI, WO2VI and UO2VI with an unsymmetrical tetradentate Schiff base ligand derived from 2-hydroxy-5-methylacetophenone, 2-hydroxy-5-methyl-3-nitroacetophenone and carbohydrazide have been prepared. All the complexes have been characterized by elemental analysis, UV-Vis and IR spectroscopy, magnetic measurements and thermal analysis. The complexes were found to be quite stable and decomposition of the complexes ended with respective metal oxides as an end product. The IR spectral data suggest that the ligand behaves as a dibasic tetradentate ligand with ONNO donor atoms sequence towards central metal ion. The solid-state electrical conductivity has been measured over 313-403 K temperature range and all the compounds showed semiconducting behavior as their conductivity increases with increase in temperature. The powder XRD study of VOIV complex suggests the triclinic crystal system to the complex. The VOIV and Mn-III complexes have been tested for the catalytic oxidation of styrene. The ligand and its some of the complexes have also been screened for their antimicrobial activity using various micro-organisms and all of them were found to be moderately active against the organisms.