Standard molar enthalpy of formation of Nd(Gly)2(Ala)3Cl3·2H2O(s)

The mixed complex of Nd3+ with glycine and alanine, Nd(Gly)2(Ala)3Cl3·2H2O, was synthesized and characterized by IR, elementary analysis, thermogravimatric analysis and chemical analysis, and the dissolution enthalpies of NdCl3·6H2O(s), 2Gly(s) + 3Ala(s) and Nd(Gly)2(Ala)3Cl3·2H2O(s) were determined in 2 mol/L HCl by the classical solution calorimetry. By designing a thermochemical cycle according to Hess‘ law and through calculation, we obtained the reaction enthalpy of neodymium chloride six-hydrate with glycine and alanine: ΔrH°m(298.15 K)=37.24±0.299 kJ/mol, and the standard enthalpy of formation of Nd(Gly)2(Ala)3Cl3·2H2O(s): ΔfH°m[Nd(Gly)2(Ala)3Cl3·2H2O, s, 298.15 K] = −4441.6±8.262 kJ/mol.