A Monte Carlo simulation study of solvent effect on Eu3+ to Nd3+ ion mutation

The solvent effects on the relative free energies of salvation of Eu3+ to N d3+ ion mutation have been investigated using a Monte Carlo simulation of s tatistical perturbation theory. Comparing the relative free energies of Eu3 + to Nd3+; ion mutation, in H2O (TIP4P) in this study with those of the pub lished works, that in H2O (TIP4P) is -19.11 +/- 0.36 kcal/mol in this study , that of the published work in H2O (TIP3P) is -23.6 kcal/mol and that of e xperimental work is -19.2 kcal/mol, respectively. There is good agreement a mong the three studies, considering both methods of obtaining hydration fre e energies and the standard deviations. For the present Eu3+ and Nd3+ ions, the relative free energies of solvation vs. Born's function of bulk solven ts decrease with increasing Born's function of bulk solvents except for CH3 OH, THF and MeOMe. The strong ion-solvent intel actions in CH3OH, THF and M eOMe solutions could be due to the electron pair donor properties of the so lvents to ion, i.e., Donor number of CH3OH. THF and MeOMe established by Gu tmann. There is also good agreement between the calculated structural prope rties in this study and the published works obtained by computer simulation s and experiments. (C) 2001 Elsevier Science B.V. All rights reserved.