Thermochemical study of mixed ligand complexes of rare earths with glycine andL-alanine

In order to obtain the standard molar enthalpies of formation of Rare-Earth amino acid coordination compounds, precise isothermal solution-reaction calorimetric method was used. The value of ΔrH m Θ of two coordination reactions was determined at T=298.2 K. From the experimental results and other auxiliary values, the standard molar enthalpies of formation of Ln(Gly)5/2(Ala)3/2(ClO4)3·H2O(s) [Ln=La, Yb] at T=298.2 K were obtained. The values of them is to be ΔrH m Θ [La(Gly)5/2(Ala)3/2(ClO4)3·H2O(s)]=−3545.45 kJ/mol and ΔrH m Θ [Yb(Gly)5/2(Ala)3/2)(ClO4)3·H2O(s)]=−3793.81 kJ/mol, respectively.