Excited state dynamics of carotenoids free and bound to pigment-protein complexes
| Main Authors: | Rondonuwu, Ferdy S., Koyama, Yasushi |
|---|---|
| Format: | Proceeding application/pdf |
| Terbitan: |
Satya Wacana University Press
, 2016
|
| Subjects: | |
| Online Access: |
http://repository.uksw.edu/handle/123456789/7201 |
Daftar Isi:
- Proceedings of the International Conference on Science and Science Education August 2015, p. AZ.12-22 Available on http://fsm.uksw.edu/ojs/index.php/2015/article/view/77
- Excited state dynamics and energetics of carotenoids having a different number of conjugated double bonds (n), which include spheroidene (n = 9) and lycopene (n = 10) free and bound to LH2 complexes from Rhodobacter spaheroides 2.4.1 and Rhodospirillum moliscianum have been evaluated with the use of time-resolved absoprtion spectroscopy. A relaxation path, including a 11Bu+-> 11Bu–> 21Ag–>11Ag– singlet internal conversion and a 11 Bu–> T (triplet) has been identified for Car free in a solution. In antenna complexes, an additional two paths were identified as Car-to-BChl singlet-energy transfer channels; first starting from the 11 Bu+and/or 11Bu– states to the Qx state, and second starting from the 21 Ag– state to the Qy state. The second channel may be deactivated depending on the number of conjugated double bonds (n). The 21 Ag – (donor) state of spheroidene (n = 9) promotoes the singlet-energy transfer to the Qy (aceptor) state of BChl. In contrast to spheroidene, the 21 Ag– state of lycopene (n = 10) prevents the energy transfer process.