(181ac) Simulation and Experimental Benchmarking of the Thermophysical Properties of N-Functionalized Alkylimidazoles

Molecular simulations are used to probe the thermophysical properties of a series of N-functionalized alkylimidazoles, ranging from N-methylimidazole to N-heptylimidazole.  These compounds have been previously synthesized, and their solvation properties have been shown to be potentially useful for CO₂ capture from industrial sources.  We report first-principles calculations, which are used to fit electrostatic charges to the molecular models, which are then implemented in a series of molecular dynamics simulations.  Over a range of different temperatures, we benchmark the simulated densities and heat capacities against experimental measurements.  Also, we predict the Henry’s constants for CO₂ absorption and probe the solvents’ structures using molecular simulation techniques, such as fractional free volume analysis and void distributions.  The simulations demonstrate excellent agreement when comparing density values, and the predictions of the heat capacities and Henry’s constants for CO₂ absorption are in very good qualitative agreement with the experiments.  Overall, we find that our simulations are able to closely reproduce the experimental benchmarks and add additional insight into the molecular structure of these fluids, with respect to their observed solvent properties.