|
ИСТИНА |
Войти в систему Регистрация |
ИСТИНА ИНХС РАН |
||
Identification of the high-energy conformer of octa-1,3,5,7-tetraene detected in the one-photon excitation fluorescence spectrumстатья
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 18 июля 2013 г.
- Авторы: Panchenko Y.N., Bock C.W., Abramenkov A.V., Larkin J.D.
- Журнал: Structural Chemistry
- Том: 20
- Номер: 6
- Год издания: 2009
- Издательство: Springer-Verlag
- Местоположение издательства: Heidelberg, Germany
- Первая страница: 983
- Последняя страница: 993
- DOI: 10.1007/s11224-009-9501-5
- Аннотация: Scaled quantum-mechanical force field (SQM-FF) vibrational analyses at the HF/6-31G//HF/6-31G computational level of the gauche, Trans,trans,Trans,trans-, gauche,Trans,trans,Cis,trans-, trans,Trans,gauche,Trans,trans-, and trans,Cis,trans,Trans,trans-conformers of octa-1,3,5,7-tetraene were used to identify the rotational isomer observed in the one-photon excitation fluorescence spectrum of this conjugated molecule (Ackerman et al. in J Chem Phys 80:39-44, 1984) as the gauche,Trans,trans,Trans,trans (gTtTt)-conformer. The analysis was performed by comparing the RMS deviations of the 14 fundamental wavenumbers assigned to the high-energy conformer of octa-1,3,5,7-tetraene in the fluorescence spectrum with those calculated for these conformers. Some reassignments of the wavenumbers, originally suggested by experimental observations, were required for the current analysis. The non-planar structure of gTtTt-octa-1,3,5,7-tetraene was calculated to have the terminal -CH=CH(2) moiety rotated by similar to 30.5A degrees with respect to the remainder of the nearly planar skeleton using both the HF/6-31G and MP2(FC)/aug-cc-pVDZ computational levels. The barriers to rotation of the -CH=CH(2) moiety at the MP2(FC)/aug-cc-pVDZ level were as follows: rotation from the lowest-energy planar all-trans conformer to the non-planar gTtTt-conformer was 31.4 kJ/mol; rotation from the gTtTt-conformer to the planar all-trans conformer was 18.0 kJ/mol; and the barrier between the two equivalent gTtTt-octa-1,3,5,7-tetraene conformers was only 1.4 kJ/mol.
- Добавил в систему: Панченко Юрий Николаевич