Solvation structure and thermodynamics for Pr(III), Nd(III) and Dy(III) complexes in ionic liquids evaluated by Raman spectroscopy and DFT calculation

Moreover, optimized geometries and binding energies of [Pr(III)(cis-TFSA)5]2−, [Nd(III)(cis-TFSA)5]2−, and [Dy(III)(cis-TFSA)5]2− clusters were also investigated by DFT calculations using the ADF package. The bonding energy, ΔEb, was calculated as ΔEb = Etot(cluster) − Etot(RE3+) − nEtot([TFSA]−), and ΔEb ([Pr(III)(cis-TFSA)5]2−), ΔEb([Nd(III)(cis-TFSA)5]2−), and ΔEb([Dy(III)(cis-TFSA)5]2−) were calculated to be −4238.6 ± 6.8, −4362.3 ± 8.2, and −4284.2 ± 7.4 kJ mol−1, respectively. This series of structural results allows us to conclude that [Dy(III)(cis-TFSA)5]2− clusters are more stable state than the [Pr(III)(cis-TFSA)5]2− clusters in [P2225][TFSA]. Furthermore, the average atomic charges and the bond distances of these clusters were consistent with the thermodynamic properties.