Excited‐state structure and photochemical ring‐opening dynamics of 1,3,5‐cyclo‐octatriene from absolute resonance Raman intensities
| العنوان: | Excited‐state structure and photochemical ring‐opening dynamics of 1,3,5‐cyclo‐octatriene from absolute resonance Raman intensities |
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| المؤلفون: | Richard A. Mathies, Mary K. Lawless |
| المصدر: | The Journal of Chemical Physics. 100:2492-2504 |
| بيانات النشر: | AIP Publishing, 1994. |
| سنة النشر: | 1994 |
| مصطلحات موضوعية: | Absorption spectroscopy, Chemistry, Overtone, General Physics and Astronomy, Resonance, Ring (chemistry), Photochemistry, symbols.namesake, Normal mode, Excited state, symbols, Physical and Theoretical Chemistry, Conrotatory and disrotatory, Raman spectroscopy |
| الوصف: | Absolute resonance Raman cross sections are measured for 1,3,5‐cyclo‐octatriene (COT) in cyclohexane with excitation from 325 to 200 nm. These intensities and the absorption spectrum are modeled using a fully thermalized time‐correlator theory to quantitate the excited‐state equilibrium geometry displacements along 19 Raman‐active normal modes. The resonance Raman spectra show significant intensity in low‐frequency modes corresponding to planarization of the eight‐membered ring. The 140 cm−1 twist‐boat planarization (Δ=4.6) and the 339 cm−1 ring deformation (Δ=1.6) are particularly strong. However, no intensity is observed in modes which project onto the predicted disrotatory ring‐opening motion, such as the nontotally symmetric CH2 twist fundamental or its overtone. Analysis of the fluorescence quantum yield (φF=2×10−6) gives an excited state lifetime on the order of ∼30 fs. These results show that ring planarization is the first step in the disrotatory ring opening of COT followed by rapid depopulation ... |
| تدمد: | 1089-7690 0021-9606 |
| DOI: | 10.1063/1.466498 |
| URL الوصول: | https://explore.openaire.eu/search/publication?articleId=doi_________::3f6f9dfa95b59da24f7125f010d2ce5a https://doi.org/10.1063/1.466498 |
| رقم الانضمام: | edsair.doi...........3f6f9dfa95b59da24f7125f010d2ce5a |
| قاعدة البيانات: | OpenAIRE |
| تدمد: | 10897690 00219606 |
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| DOI: | 10.1063/1.466498 |