Neighbor Group Hydration Effects on Carboxylate Basicities in Partly Aqueous Solutions |
| |
| Authors: | Judit Nyíri Béla Noszál |
| |
| Affiliation: | 1. Department of Inorganic and Analytical Chemistry, L. E?tv?s Lóránd University, Pázmány sétány. 1/A., H-1117, Budapest, Hungary
2. Department of Pharmaceutical Chemistry, Semmelweis University, Research Group for Abuse Drugs and Dopings, Hungarian Academy of Sciences, H-1092, Budapest, H?gyes Endre u. 9., Hungary
|
| |
| Abstract: | Protonation constants of carboxylate groups in a variety of compounds were determined in 1,4-dioxane + water solvent mixtures and have been found to depend on the local solvent composition, and their values are modified by adjacent moieties with diferent polarity occurring on the compounds. A relationship has been found between log10K values and solvent composition, and by the neighboring group. Using acetic acid as a reference compound, the extent of the local hydration effect was estimated, and it has been found to be strong for α-ammonium sites, and moderate for nearby peptide and thiol groups. On the other hand, an extra methylene moiety has been found to bring about a moderate dehydration effect. The observed hydration/dehydration effects were observed in the 12–40 mole% range of the actual bulk solvent composition. |
| |
| Keywords: | Water-1,4-dioxane mixed solvents carboxylate basicity hydration effect solvation |
| 本文献已被 SpringerLink 等数据库收录！ |
|
