Stability constants of , Th⁴⁺and Ce³⁺withL-asparagine and thermodynamic parameters

The stability constants of L-asparagine and its complexes formed with , Th4+ and Ce3+ ions were determined potentiometrically using the Calvin–Bjerrum technique as adopted by Irving and Rossotti at different temperatures (290, 298 and 310 K), in 0.1 M KCl. The stability constants were computed using the least-squares treatment method in EXCEL program for proton–ligand and metal–ligand at the temperatures given above. The protonation constants of L-asparagine (log β2) were found to be 13.07 ± 0.01, 12.58 ± 0.10, 12.28 ± 0.16 at 290, 298 and 310 K, respectively. In addition, the thermodynamic parameters ΔH, ΔG and ΔS of L-asparagine and its complexes with metal ions were evaluated and discussed at the same temperatures.