Universal Trends between Acid Dissociation Constants in Protic and Aprotic Solvents

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
Degree programme
Chemistry - A European Journal, Volume 28, issue 59
pKa values in non-aqueous solvents are of critical importance in many areas of chemistry. Our knowledge is, despite their relevance, still limited to the most fundamental properties and few pKa values in the most common solvents. Taking advantage of a recently introduced computationally efficient procedure we computed the pKa values of 182 compounds in 21 solvents. This data set is used to establish for the first time universal trends between all solvents. Our computations indicate, that the total charge of the molecule and the charge of the acidic group combined with the Kamlet-Taft solvatochromic parameters are sufficient to predict pKa values with at least semi- quantitative accuracy. We find, that neutral acids such as alcohols are strongly affected by the solvent properties. This is contrasted by cationic acids like ammonium ions whose pKa is often almost completely independent from the choice of solvent.
Funding Information: Calculations were performed at the Chalmers Centre for Computational Science and Engineering (C3SE) and the Finnish IT centre for science (CSC). M.B. and K.L. acknowledge financial support from the Jane and Aatos Erkko Foundation through the “Renewable energy storage to high value chemicals” project. M.B. also acknowledges support from the Dr. Barbara‐Mez‐Starck foundation. Open Access funding enabled and organized by Projekt DEAL. Publisher Copyright: © 2022 The Authors. Chemistry - A European Journal published by Wiley-VCH GmbH.
DFT, diazepam, ibuprofen, morphine, non-aqueous solvents, pharmacology, pKa
Other note
Busch, M, Ahlberg, E & Laasonen, K 2022, ' Universal Trends between Acid Dissociation Constants in Protic and Aprotic Solvents ', Chemistry: A European Journal, vol. 28, no. 59, e202201667 . https://doi.org/10.1002/chem.202201667