(709a) Computational Study of the Proton Affinity, 1 H NMR Chemical Shifts, and Thermophysical Properties of Imidazole Derivatives

Liu, H., University of Alabama
Bara, J. E., University of Colorado
Turner, C. H., University of Alabama

There has been increasing interest in developing new materials for CO2 capture. One of the approaches is to synthesize polymer membrane using imidazole derivatives as the monomer. These imidazole derivatives are able to react with aqueous CO2 to form bicarbonate anions, thus enabling facilitated transport of CO2 through the membrane. In order to better understand the chemical and thermophysical properties of imidazole derivatives, we have employed quantum mechanics and molecular dynamics methods to calculate the proton affinities, 1H NMR chemical shifts, and absorption properties of a variety of imidazole derivatives. From our simulations, a quantitative characterization of the effect of various exocyclic substituents on the proton affinity of imidazole was achieved. In particular, we find that electron-donating groups are able to increase the proton affinity of imidazole. In addition, the calculated 1H NMR chemical shift and thermophysical properties are in excellent with experiment. These results will be helpful for future experimental design of new materials to be used for CO2 capture.