Thermoanalytical study about histidine and cysteine-cadmium interactions

Infrared spectroscopy, thermogravimetry and differential scanning calorimetry techniques were used to study the metal-amino acid interactions for adducts of the general formula CdCl₂·nL (n=1.0 or 1.5 and L=histidine or cysteine). After characterization the thermal degradation process was kinetically followed by a non-isothermal method. The infrared data confirmed that the cation is coordinated the carboxylic oxygen atoms of the amino acid molecules. The thermogravimetric results indicated that the main step of the thermal degradation of all amino acid adducts is connected to the rupture of the metal-ligand bonds, to give the associated activation energies values of 77, 44, 55 and 41 kJ mol^-1 for CdCl₂·nL, n=1.0 and 1.5, for histidine and cysteine, respectively. This revised version was published online in July 2006 with corrections to the Cover Date.