Comparative study on the gas to solution phase solvation free energies of model combustion flue gas compounds (N~2~, O~2~, CO~2~, H~2~O, SO~2~, and CO) in 178 organic solvents using the IEFPCM-UFF, CPCM, and SMD implicit solvent models at the Gaussian-4 (G4) level of theory

Sierra Rayne,Kaya Forest

doi:10.1038/npre.2010.5227.1

Abstract

AbstractGas 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.

Highlights

Implicit solvation models are widely employed in theoretical studies to investigate the energetics of transferring molecules between gas, liquid, and solid phases, and for studying molecular structures, physical properties, and intra- and intermolecular reactions in the solution phase [1]
The majority of benchmarking efforts and applied studies using these types of solvent models are in aqueous solution, with generally more limited work conducted in a relatively small set of common organic solvents such as acetonitrile, dimethylsulfoxide, n-octanol, and methanol, among others
A common property calculated by implicit solvation models is the gas to solution phase Gibbs free energy of solvation for small molecules, which is of value in calibrating/validating the theoretical models and of intrinsic interest for predicting partitioning behavior [23]

Summary

Introduction

Implicit solvation models are widely employed in theoretical studies to investigate the energetics of transferring molecules between gas, liquid, and solid phases, and for studying molecular structures, physical properties, and intra- and intermolecular reactions in the solution phase [1]. The majority of benchmarking efforts and applied studies using these types of solvent models are in aqueous solution, with generally more limited work conducted in a relatively small set of common organic solvents such as acetonitrile, dimethylsulfoxide, n-octanol, and methanol, among others

Results

Conclusion