Copper(II) Complexes of Organophoshonic Acids-A Comparative Study

Abstract

Polynuclear copper(II) derivatives of 1-hydroxyethylidenediphosphonic acid (HEDP), 1-aminoethylidenediphosphonic acid (AEDP, H₄L), α-aminobenzylidene diphosphonic acid (ABDP, H₄L), 1-amino-2-carboxyethane- 1,1-diphosphonic acid (ACEDP, H₅L), 1,3 diaminopropane-1,1,3,3-tetra-phosphonic acid (DAPTP, H₈L), Ethylenediamine-N,N'-bis (dimethyl-methylenephosphonic) acid (EDBDMPO, H₄L), o-phenylene-diamine-N,N'-bis (dimethylmethylenephosphonic) acid (PDBDMPO, H₄L), diethylene triamine –N,N,N',N',N"N-penta (methylene phosphonic) acid (DETAPMPO, H₁₀L) and diethylene triamine –N,N"-bis (dimethyl methylene phosphonic) acid (DETBDMPO, H₄L) have been prepared in aqueous medium. The general formula of derivatives from elemental analysis was found to be Cu₂L.XH₂O (in case of AEDP, ABDP, EDBDMPO, PDBDMPO, DETBDMPO), Cu₅L₂.XH₂O (in case of ACEDP) Cu₄L.XH₂O, Cu₂ H₄L. XH₂O (in case of DAPTP) and Cu₅L.XH₂O (in case of DETAPMPO). The electronic spectra have shown them to be six coordinated with slight distortion from octahedral geometry. Antiferromagnetism was inferred from magnetic moment data. Infrared spectral studies were carried out to determine coordination sites. EPR (Electron Paramagnetic Resonance) spectra that supports the presence of tetragonal distortion and antiferromagnetic behaviour, have also been studied.