Synthesis, spectroscopic and thermal investigation of Schiff-base complexes of Cu(II) derived from heterocyclic β-diketone with various primary amines

Abstract

The mononuclear complex [Cu(PMFP)(bipy)]ClO4 was prepared by reaction of Cu(NO3)2·5H2O with ligand PMFP and 2,2′-bipyridine. The corresponding Schiff bases were prepared by condensation of [Cu(PMFP)(bipy)]ClO4 with ethylenediamine, ethanolamine and glycine with general formula [Cu(PMFP-SB)(bipy)]ClO4 (where PMFP = 1-phenyl-3-methyl-4-formyl-2-pyrazolin-5one; bipy = 2,2′-bipyridine). All the compounds have been characterized by elemental analysis, magnetic susceptibility, conductometry measurements and 1H-NMR, FT-IR, ESR, electronic spectra and mass spectrometry. Electronic spectra and magnetic susceptibility measurements indicate square planar stereochemistry. Thermal stability, order of kinetics, heat capacity and activation energy of thermal degradation for these complexes were determined by TGA and DSC. Hamiltonian and bonding parameters from ESR spectra indicate the metal ligand bonding is partially covalent.