Institute of theoretical chemistry, Ulm University, Albert-Einstein Allee 11, 89069, Ulm, Germany.
Department of chemistry and material science, School of chemical engineering, Aalto University, Kemistintie 1, 02150, Espoo, Finland.
Chemistry. 2022 Oct 21;28(59):e202201667. doi: 10.1002/chem.202201667. Epub 2022 Aug 25.
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.
pKa 值在非水溶剂中对于化学的许多领域都至关重要。尽管它们具有相关性，但我们的知识仍然局限于最基本的性质和少数最常见溶剂中的 pKa 值。利用最近引入的一种计算效率高的方法，我们计算了 21 种溶剂中 182 种化合物的 pKa 值。该数据集首次用于建立所有溶剂之间的通用趋势。我们的计算表明，分子的总电荷和酸性基团的电荷与 Kamlet-Taft 溶剂化参数相结合，足以预测 pKa 值，至少具有半定量的准确性。我们发现，像醇这样的中性酸会受到溶剂性质的强烈影响。与之形成对比的是阳离子酸，如铵离子，其 pKa 值通常几乎完全独立于溶剂的选择。
