Synthesis and structural studies of complexes of Co(ll), Ni(ll), Cu(ll), Zn(II) and Cd(ll) with substituted chalcones

Abstract

Complexes of Co(II), Ni(II), Cu(II), Zn(lI) and Cd(II) with 3-(2-pyridyl)-l- (2-hydroxy phenyl)-2-propen-l-one (PHPO), 3-(1-naphthyl)-l-(2-hydroxy phenyl)-2- propen-l-one (NHPO) and 3-(3,4-dimethoxy phenyl)-l-(2-hydroxy phenyl)-2-propen-1- one (DMPHPO) have been synthesized and characterized by analytical, conductivity, thermal, magnetic, infrared, electronic and electron spin resonance data. Based on ana- lytical data the stoichiometry of the complexes has been found to be 1 : 2. The conducti- vity data show that all these complexes are non-electrolytes. The infrared spectral data indicate that the ligand PHPO acts as uninegative tridentately towards Co(II) and Ni(II) and bidentately with Cu(lI), Zn(II) and Cd(II). Ligands like NHPO and DMPHPO act as uninegative bidentately with all the metal ions. The electronic spectral data suggest that all the Co(II) complexes and Ni(II) of PHPO complex are octahedral and all the Cu(II) and Ni(II) of NHPO and DMPHPO complex are square-planar. The complex of Zn(II) and Cd(II) are tetrahedral. ESR parameters of Cu(II) complexes have been calculated and relevant conclusions have been drawn with respect to the nature of bonds present in them.