Carotenoid triplet detection by time-resolved EPR spectroscopy in carotenopyropheophorbide dyads

Donatella Carbonera, Marilena Di Valentin, Carlo Corvaja, Giovanni Giacometti, Giancarlo Agostini, Paul A. Liddell, Ana L Moore, Thomas A Moore, John Devens Gust

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Carotenoid triplets play a photoprotective role in natural photosynthesis. The main process of carotenoid triplet formation is known to be triplet-triplet energy transfer from chlorophyll triplets. The structural requirements for high transfer yields are still a matter of discussion and the presence of competitive triplet formation pathways has not been excluded. Transient EPR measurements of triplet states formed by photoexcitation allow detection of the initial spin polarization. This pattern derives from the mechanism of triplet formation. In the case of triplet-triplet energy transfer, if the condition of spin angular momentum conservation is fulfilled, simulation of the EPR spectra gives information about the donor-acceptor mutual orientation. We describe transient EPR experiments on two artificial photosynthetic dyads, consisting of a carotenoid covalently-linked to a free-base or zinc substituted pyropheophorbide moiety and we discuss the results in terms of possible dyad conformations.

Original languageEnglish
Pages (from-to)329-335
Number of pages7
JournalJournal of Photochemistry and Photobiology A: Chemistry
Volume105
Issue number2-3
Publication statusPublished - May 30 1997

Fingerprint

carotenoids
Carotenoids
Paramagnetic resonance
Spectroscopy
Energy transfer
energy transfer
spectroscopy
Spin polarization
photosynthesis
Photosynthesis
Photoexcitation
Angular momentum
chlorophylls
Chlorophyll
photoexcitation
atomic energy levels
Conformations
conservation
Zinc
Conservation

Keywords

  • Carotenoids
  • Dyads
  • Porphyrins
  • TREPR
  • Triplets

ASJC Scopus subject areas

  • Bioengineering
  • Physical and Theoretical Chemistry

Cite this

Carbonera, D., Di Valentin, M., Corvaja, C., Giacometti, G., Agostini, G., Liddell, P. A., ... Gust, J. D. (1997). Carotenoid triplet detection by time-resolved EPR spectroscopy in carotenopyropheophorbide dyads. Journal of Photochemistry and Photobiology A: Chemistry, 105(2-3), 329-335.

Carotenoid triplet detection by time-resolved EPR spectroscopy in carotenopyropheophorbide dyads. / Carbonera, Donatella; Di Valentin, Marilena; Corvaja, Carlo; Giacometti, Giovanni; Agostini, Giancarlo; Liddell, Paul A.; Moore, Ana L; Moore, Thomas A; Gust, John Devens.

In: Journal of Photochemistry and Photobiology A: Chemistry, Vol. 105, No. 2-3, 30.05.1997, p. 329-335.

Research output: Contribution to journalArticle

Carbonera, D, Di Valentin, M, Corvaja, C, Giacometti, G, Agostini, G, Liddell, PA, Moore, AL, Moore, TA & Gust, JD 1997, 'Carotenoid triplet detection by time-resolved EPR spectroscopy in carotenopyropheophorbide dyads', Journal of Photochemistry and Photobiology A: Chemistry, vol. 105, no. 2-3, pp. 329-335.
Carbonera D, Di Valentin M, Corvaja C, Giacometti G, Agostini G, Liddell PA et al. Carotenoid triplet detection by time-resolved EPR spectroscopy in carotenopyropheophorbide dyads. Journal of Photochemistry and Photobiology A: Chemistry. 1997 May 30;105(2-3):329-335.
Carbonera, Donatella ; Di Valentin, Marilena ; Corvaja, Carlo ; Giacometti, Giovanni ; Agostini, Giancarlo ; Liddell, Paul A. ; Moore, Ana L ; Moore, Thomas A ; Gust, John Devens. / Carotenoid triplet detection by time-resolved EPR spectroscopy in carotenopyropheophorbide dyads. In: Journal of Photochemistry and Photobiology A: Chemistry. 1997 ; Vol. 105, No. 2-3. pp. 329-335.
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