Ligating properties of 1H- imidazole -4-carboxylic acid

Synthesis of 1H - imidazole - 4 - carboxylic acid complexes derived from cobalt [II], nickel [II], copper [II], palladium [II] and platinum [IV] salts, were carried out. The elemental analyses suggest the formation of l:l, l:2 and l:4 stoichiometries [M:L].Spectral [UV -Vis., and IR] and magnetic susceptibility measurements identified the structures of the complexes. The geometry and the mode of bonding of the complexes were deduced. The thermodynamic parameters of decomposition were calculated. The complexes are of semiconductor properties

role of some metal ions on the dissociation of disubstituted arylazo barbituric and thiobarbituric acids

Potentiometric studies of some disubstituted arylazo barbituric and thiobarbituric acids were carried out. The dissociation constants of the organic compounds and the stability constants of the metal complexes were calculated. The nodes of ionization of the free ligands were explained. The data were explained from different views: the ionization potential of the metal, the atomic radius of the metal and the electronic character of the substituent. A linear free energy relationship between pK[L]and log K[C]values were deduced and explained