2002年3月
Cis-to-traps isomerization of spheroidene in the triplet state as detected by time-resolved absorption spectroscopy
JOURNAL OF PHYSICAL CHEMISTRY A
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- 巻
- 106
- 号
- 11
- 開始ページ
- 2410
- 終了ページ
- 2421
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1021/jp011309n
- 出版者・発行元
- AMER CHEMICAL SOC
Cis-to-trans isomerization upon excitation of the all-traps, 9'-cis, 13'-cis, 9-cis, 13-cis, and 15-cis isomers of spheroidene to the triplet state (by the use of anthracene as a sensitizer) was traced by submicrosecond time-resolved absorption spectroscopy. The time-resolved spectra were analyzed by means of singular-value decomposition and subsequent global fitting using a scheme having potential minima at the cis and trans positions in both the T-1 and S-0 states. The quantum yields of triplet-sensitized isomerization were also determined. The process of cis-to-trans isomerization in the T-1 state was clearly seen for the 13'-cis and 9-cis isomers. The quantum yield and the rate of cis-to-trans isomerization increased systematically in the order 13'-cis, 9-cis, 13-cis, and 15-cis T-1 species, whereas their rates of T-1 --> S-0 intersystem crossing were similar to one another and 6 times larger than that of the all-traps T-1 species. The T-n <-- T-1 absorption maximum shifted to the blue in the above order, and reached to that of the all-traps T-1 species. Those observations were explained in terms of "the triplet-excited region" localized in the central part of the conjugated chain. A possible reason for the selection of the 15-cis configuration by a bacterial photoreaction center containing this carotenoid was discussed.
- リンク情報
- ID情報
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- DOI : 10.1021/jp011309n
- ISSN : 1089-5639
- CiNii Articles ID : 80015131597
- Web of Science ID : WOS:000174551200005