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Photoisomerization Paths of α,ω-Diphenylpolyenes: Reaction Rate Dependence on Temperature, Excitation Wavelength, and Deuterationстатья
Статья опубликована в высокорейтинговом журнале
Статья опубликована в журнале из списка Web of Science и/или Scopus- Авторы: Dobryakov Alexander L., Schriever Daria, Quick Martin, Pérez-Lustres J.Luis, Ioffe Ilya N., Kovalenko Sergey A.
- Журнал: Journal of the American Chemical Society
- Год издания: 2024
- Издательство: American Chemical Society
- Местоположение издательства: United States
- DOI: 10.1021/jacs.4c09134
- Аннотация: The photoisomerization rate kiso of trans-stilbene (tS) and trans–trans-diphenylbutadiene (ttD) is studied in solution and compared to that in jet/gas. Rice–Ramsperger–Kassel–Marcus (RRKM) theory correctly predicts the tS rate in jet, kRRKM = Am exp(−Ein/kTm) with Ein = 1398 cm–1, and Am = 1.8 ps–1 corresponding to frequency νiso = 60 cm–1 of the reactive mode, Tm being the molecular temperature. However, the behavior in solution cannot be explained by the RRKM rate alone. In solution the rate kiso = AS exp(−Eb/kTS) has a similar form, but depends mainly on solvent temperature TS and proceeds much faster, AS = 19 ps–1, Eb = 1520 cm–1 in n-hexane. Moreover, excitation at high excess energy, resulting in molecular temperature Tm = 607 K, affects the rate only slightly, unlike in jet, and contrary to common theoretical models. The experimental results clearly indicate two isomerization paths in solution: via relatively slow intramolecular activation Am ∼ 1 ps–1, and by much faster solvent activation AS = 18 ps–1 due to solute–solvent interactions (collisions). The data in n-alkanes confirm previously established power dependence kiso ∼ ηα on viscosity η, with α = 0.30 for tS, and α = 0.35 for ttD. With Eη being the viscosity barrier, its contribution to Eb can be isolated, giving the intramolecular barrier Ein = (Eb – αEη), slightly lower than in jet/gas, probably due to the dispersive/induction interactions in solution.
- Добавил в систему: Иоффе Илья Нафтольевич
Прикрепленные файлы
| № | Имя | Описание | Имя файла | Размер | Добавлен |
|---|---|---|---|---|---|
| 1. | Полный текст | dobryakov-et-al-2024-photoisomerization-paths-of-α-ω-diphen… | 3,2 МБ | 22 ноября 2024 [Ioffe] | |
| 2. | Экспертное заключение | zakl-jacs.pdf | 1,3 МБ | 22 ноября 2024 [Ioffe] |