METAL-CHELATES WITH SOME CELLULOSE DERIVATIVES .3. SYNTHESIS AND STRUCTURAL CHEMISTRY OF NICKEL(II) AND COPPER(II) COMPLEXES WITH CARBOXYMETHYL CELLULOSE

Cu(II) and Ni(II) complexes with three grades of carboxymethyl cellulose (CMC) with different degrees of substitution have been synthesized and characterized. Probable structures of the metal complexes are inferred from the electronic and IR spectra, elemental analysis data and magnetic moment measurements. CMC coordinates with Cu(II) and Ni(II) via the carboxymethyl and hydroxyl groups. The effect of the degree of substitution of the CMC on the mode of chelation is discussed. Ni(II) complexes show an octahedral geometry around the metal ion and exhibit the formula [NiL . 4H(2)O]Cl. Cu(II) complexes exist in the square planar form and have the formula Cu(L)(2), where L is uninegatively charged bidentate CMC ligand. The ligand field parameters of Ni(II) complexes are also evaluated.