Computation of the pKa values of some neutral molecules and anions in aqueous solution

CHED 959

Daqing Gao,, Yinjuan Cui, Ermir Pjetri, Anibal Davalos, Eza Chikashvili, and Jessica Lenis. Department of Chemistry, Queensborough Community College of The City University of New York, 222-05 56th Avenue, Bayside, NY 11364
In this paper, we present our results on the computation of the pKa values of some neutral molecules and anions, including the carbon acids acetonitrile, methyl acetate, acetamide, N,N-dimethylacetamide, as well as acetate, bicarbonate, and dihydrogenphosphate, in aqueous solution by using a variety of solvation models such as the CPCM in Gaussian 03 and SM6 in Smxgauss and high level gas phase ab initio MO calculations. In particular, we treated the solute molecule with one, two and three water molecules in the continuum model. This work provides important information on the use of explicit water molecules with the continuum models in the pKa calculations.