First-principle predictions of absolute pKa's of organic acids in dimethyl sulfoxide solution

Yao Fu; Lei Liu; Rui-Qiong Li; Rui Liu; Qing-Xiang Guo

doi:10.1021/ja0378097

First-principle predictions of absolute pKa's of organic acids in dimethyl sulfoxide solution

J Am Chem Soc. 2004 Jan 28;126(3):814-22. doi: 10.1021/ja0378097.

Authors

Yao Fu¹, Lei Liu, Rui-Qiong Li, Rui Liu, Qing-Xiang Guo

Affiliation

¹ Department of Chemistry, University of Science and Technology of China, Hefei 230026, China.

PMID: 14733556
DOI: 10.1021/ja0378097

Abstract

MP2/6-311++G(d,p) and B3LYP/6-311++G(2df,p) methods were found to be able to predict the gas-phase acidities of various organic acids with a precision of 2.2 and 2.3 kcal/mol. A PCM cluster-continuum solvation method was developed that could predict the solvation free energies of various neutral, cationic, and anionic organic species in DMSO with a precision of about 2.0 kcal/mol. Using these carefully tested methods, we successfully predicted the pKa's of 105 organic acids in DMSO with a precision of 1.7-1.8 pKa units. We also predicted the pKa's of a variety of organosilanes in DMSO for the first time using the newly developed methods. This study was one of the first that employed first-principle methods for calculating pKa's of unrelated compounds in organic solutions.