Carbon Dioxide in Aqueous Environment-A Quantum Mechanical Charge Field Molecular Dynamics Study

Structure and dynamics of a carbon dioxide molecule in water were studied by an ab initio quantum mechanical charge field molecular dynamics (QMCF-MD) simulation. Radial distribution functions, angular distribution functions, and coordination number distributions as well as dynamical data such as mean ligand residence time and vibrational spectra were utilized for the evaluation of physico-chemical properties of hydrated CO2. These data served for an assessment of hydrogen bonding between solute and solvent molecules. All the results evaluated were compared with available experimental results leading to a good agreement between theoretical and experimental data. The average lifetime of hydrogen bonding between H2O and CO2 resulted as 0.61 ps, which is higher than the hydrogen bonding lifetime of pure water. The vibrational frequencies were also calculated for all the modes of hydrated CO2 to demonstrate the influence of solvent molecules on the IR spectrum of the solute. (C) 2010 Wiley Periodicals, Inc. Int J Quantum Chem 111: 1370-1378, 2011