Comparative study on the gas to solution phase solvation free energies of model combustion flue gas compounds (N2, O2, CO2, H2O, SO2, and CO) in 178 organic solvents using the IEFPCM-UFF, CPCM, and SMD implicit solvent models at the Gaussian-4 (G4) level of theory

Abstract

Gas to solution phase Gibbs free energies of solvation at 298.15 K for transfer of six representative combustion flue gas compounds (N~2~, O~2~, CO~2~, H~2~O, SO~2~, and CO) were calculated at the Gaussian-4 (G4) level of theory using the IEFPCM-UFF, CPCM, and SMD implicit solvent models for 178 organic solvents. The IEFPCM-UFF and CPCM models yield similar free energies of solvation for all six compounds in each of the solvents considered, having maximum absolute intra-solvent deviations <1.6 kJ mol^-1^. Substantial free energy of solvation differences were observed between the IEFPCM-UFF/CPCM and SMD models, with maximum absolute intra-solvent deviations up to 45.5 kJ mol^-1^. The IEFPCM-UFF and CPCM models displayed strong free energy of solvation correlations with the solvent dielectric constant for each compound, whereas the SMD model exhibits a significantly more variable free energy of solvation relationship with the solvent dielectric constant.