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Computational Study of the Influence of Solvent on <sup>16</sup>O/<sup>18</sup>O Equilibrium Isotope Effects in Phosphate Deprotonation Reactionsстатья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 15 мая 2024 г.
- Авторы: Kolmodin Karin, Luzhkov Victor B., Åqvist Johan
- Журнал: Journal of the American Chemical Society
- Том: 124
- Номер: 34
- Год издания: 2002
- Издательство: American Chemical Society
- Местоположение издательства: United States
- Первая страница: 10130
- Последняя страница: 10135
- DOI: 10.1021/ja012669r
- Аннотация: Results from theoretical calculations of 16 O/ 18 O equilibrium isotope effects (EIEs) on deprotonationof phosphate and methyl phosphate monoanions as well as their deuterated counterparts are reported. The EIEs are calculated from the Bigeleisen equation using harmonic vibrational frequencies from several quantum mechanical methods (HF, DFT, MP2, and AM1). All methods correctly predict the qualitative trends in the EIEs related to the different isotope substitutions. However, the calculated gas-phase values are found to be systematically higher than those experimentally observed in aqueous solution. On the other hand, the addition of explicit solvent molecules (up to 24 waters) in the first solvation shells of the phosphate ion substantially improves the calculated EIE, which approaches the experimental value withincreasing size of the water cluster. The large effects of surrounding water molecules on the phosphatedeprotonation EIE can be explained by the strong solute-solvent interactions, which result in solvent coupledvibrational modes of the phosphate ions.
- Добавил в систему: Лужков Виктор Борисович