Potentiometric and H-1 NMR studies of binary and ternary complexes of thiamine hydrochloride with copper (II), zinc (II), nickel (II) or cobalt (II) and various secondary ligands

The interaction of thiamine hydrochloride with Cu (II), Zn (II), Ni (II), C o (II) and different secondary ligands like imidazole, tryptophan, phenylal anine, pyridine, 2,5-dicarboxylic acid, thiodiacetic acid, thiodipropionic acid and iminodiacetic acid have been studied potentiometrically. The inter action of these ligands with thiamine and tryptophan or thiamine and imidaz ole with Zn (II) in D2O solution have also been studied by H-1 NMR and the changes observed confirm the inter-ligand interactions between thiamine and TRP or thiamine and imidazole. The electronic spectra also confirm the int er-ligand interactions between thiamine and TRP or phenylalanine.