Ab Initio and Density Functional Predictions of Solvation Free Energies of Cyclic Polyethers (CH2CH2O)n (n=2,6) in Aqueous and Tetrachloromethane Solutions

Abstract

Solvation free energies ∆G sol tot of cyclic polyethers (CH 2 CH 2 O) n (n=2,6) in aqueous and tetrachloromethane solutions have been calculated at HF, MP2 and B3LYP/6-311G (d,p) levels of theory using CPCM, IEFPCM and SMD implicit solvation models. It has been found that ∆G sol tot are negative for both solvents, they increase linearly with system sizes and they are more important in water solution. The electrostatic contributions to the solvation free energies ∆G sol ele are also more important in water because of their polar nature. In water, CPCM and IEFPCM models give a close values, which are slightly different from SMD values. In tetrachloromethane solvent CPCM model seems overestimate ∆G sol ele . For both solvents the non-electrostatic contributions to the solvation free energies ∆G sol n-ele provided by SMD are remarkably different to those given by CPCM and IEFPCM models. Normal 0 21 false false false FR X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Tableau Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;}