SYNTHESIS, CHARACTERIZATION AND BIOACTIVITY OF TRANSITION METAL COMPLEXES WITH CARBOXYAMIDE DERIVED FROM PYRIDINE 2,6-DIAMINE WITH 3-HYDROXY BENZOIC ACID
BIBHESH K. SINGH *
Department of Chemistry, Government Post Graduate College, Ranikhet, Uttarakhand, India
HAMENT K. RAJOR
Department of Chemistry, Ramjas College, University of Delhi, Delhi, India
REKHA CHAUHAN
Department of Chemistry, Government Post Graduate College, Ranikhet, Uttarakhand, India
SAURABH GOYAL
Department of Chemistry, Government Post Graduate College, Ranikhet, Uttarakhand, India
*Author to whom correspondence should be addressed.
Abstract
Carboxyamide ligand N,N’-bis(3-hydroxybenzoyl)pyridine-2,6-diamine and its Co(II), Ni(II) and Cu(II) complexes have been synthesized and characterized by various physico-chemical techniques. Vibrational spectra indicate deprotonation of OH group and coordination of amide carbonyl of the ligand. Mass spectrum explains the successive degradation of the molecular species in solution and justifies ML complexes. The epr of the Cu(II) complex shows gâ•‘> g⊥> 2.03, indicated that unpaired electron most likely reside in the dx2-y2 (or less likely a dxy) ground state, which is consistent with the proposed square based geometry. Electronic spectra and magnetic susceptibility measurements reveal square planar geometry for metal complexes. X-ray powder diffraction data helps to determine the cell parameters of the complexes. Molecular structure of the complexes has been optimized by MM+ calculations and supports a square planar geometry. The bio-efficacy of the ligand and its metal complexes has been examined against the growth of bacteria In vitro to evaluate their anti-microbial potential.
Keywords: Bioactivity, carboxyamide, complexes, spectra, molecular modeling