摘要:
Metal complexes of Niacin (3-pyridin carboxylic acid) were prepared in aqueous medium and characterized by different physico-chemical methods. On the basis of elemental analysis the empirical formula of the complexes have been proposed as [Fe(C(6)H(4)NO(2))]Cl(2), [Co(C(6)H(4)NO(2))]Cl, [Zn(C(6)H(4)NO(2))]Cl, [Cd(C(6)H(4)NO(2))]Cl and [Hg(C(6)H(4)NO(2))]Cl. IR spectral data indicate that the metal-ligand bonding occurs through nitrogen atom of aromatic ring and oxygen atom of COO-group. UV-visible spectra show that Fe(III) and Co(II) complexes show d-d electronic transition in addition to pi -> pi*, n -> pi* and n -> sigma* transitions. The Fe(II) and Co(II) complexes are paramagnetic. QSTG analysis data strongly support the absence of water molecules in the complexes, and the weight of the residue corresponds to the respective metal oxides. Cyclic voltammetric studies suggest that the redox properties of Zn(II), Cd(II) and Hg(II) in their complexes are modified compared to the uncoordinated metal ion. The CV data also indicate that the charge transfer processes are not reversible.