Singlet photochemistry in model photosynthesis: Identification of charge separated intermediates by Fourier transform and CW-EPR spectroscopies

Kobi Hasharoni, Haim Levanon, Jau Tang, Michael K. Bowman, James R. Norris, Devens Gust, Thomas A. Moore, John Devens Gust

Research output: Contribution to journalArticle

74 Citations (Scopus)

Abstract

Intramolecular electron transfer from the photoexcited state of a carotenoid-porphyrin-diquinone tetrad was studied by selective laser excitation with both Fourier transform and CW EPR spectroscopies. It is shown that the electron transfer occurs from the singlet state of the porphyrin constituent to produce the terminal benzoquinone radical anion and the carotenoid radical cation. This tetrad molecule can maintain the charge-separated state for a substantial period of time (∼ 1 μs), allowing the characterization of the short-lived radicals. The derivative-like spectrum of the quinone radical anion and its dependence on the turning angle of the microwave pulse indicates that electron transfer proceeds via the singlet state.

Original languageEnglish
Pages (from-to)6477-6481
Number of pages5
JournalJournal of the American Chemical Society
Volume112
Issue number18
Publication statusPublished - 1990

Fingerprint

Photochemistry
Photosynthesis
Photochemical reactions
Fourier Analysis
Paramagnetic resonance
Spectrum Analysis
Identification (control systems)
Fourier transforms
Porphyrins
Spectroscopy
Electrons
Carotenoids
Anions
Negative ions
Laser excitation
Microwaves
Cations
Lasers
Positive ions
Derivatives

ASJC Scopus subject areas

  • Chemistry(all)

Cite this

Singlet photochemistry in model photosynthesis : Identification of charge separated intermediates by Fourier transform and CW-EPR spectroscopies. / Hasharoni, Kobi; Levanon, Haim; Tang, Jau; Bowman, Michael K.; Norris, James R.; Gust, Devens; Moore, Thomas A.; Gust, John Devens.

In: Journal of the American Chemical Society, Vol. 112, No. 18, 1990, p. 6477-6481.

Research output: Contribution to journalArticle

Hasharoni, Kobi ; Levanon, Haim ; Tang, Jau ; Bowman, Michael K. ; Norris, James R. ; Gust, Devens ; Moore, Thomas A. ; Gust, John Devens. / Singlet photochemistry in model photosynthesis : Identification of charge separated intermediates by Fourier transform and CW-EPR spectroscopies. In: Journal of the American Chemical Society. 1990 ; Vol. 112, No. 18. pp. 6477-6481.
@article{0b435073d126412ea929dc4fb84b2b56,
title = "Singlet photochemistry in model photosynthesis: Identification of charge separated intermediates by Fourier transform and CW-EPR spectroscopies",
abstract = "Intramolecular electron transfer from the photoexcited state of a carotenoid-porphyrin-diquinone tetrad was studied by selective laser excitation with both Fourier transform and CW EPR spectroscopies. It is shown that the electron transfer occurs from the singlet state of the porphyrin constituent to produce the terminal benzoquinone radical anion and the carotenoid radical cation. This tetrad molecule can maintain the charge-separated state for a substantial period of time (∼ 1 μs), allowing the characterization of the short-lived radicals. The derivative-like spectrum of the quinone radical anion and its dependence on the turning angle of the microwave pulse indicates that electron transfer proceeds via the singlet state.",
author = "Kobi Hasharoni and Haim Levanon and Jau Tang and Bowman, {Michael K.} and Norris, {James R.} and Devens Gust and Moore, {Thomas A.} and Gust, {John Devens}",
year = "1990",
language = "English",
volume = "112",
pages = "6477--6481",
journal = "Journal of the American Chemical Society",
issn = "0002-7863",
publisher = "American Chemical Society",
number = "18",

}

TY - JOUR

T1 - Singlet photochemistry in model photosynthesis

T2 - Identification of charge separated intermediates by Fourier transform and CW-EPR spectroscopies

AU - Hasharoni, Kobi

AU - Levanon, Haim

AU - Tang, Jau

AU - Bowman, Michael K.

AU - Norris, James R.

AU - Gust, Devens

AU - Moore, Thomas A.

AU - Gust, John Devens

PY - 1990

Y1 - 1990

N2 - Intramolecular electron transfer from the photoexcited state of a carotenoid-porphyrin-diquinone tetrad was studied by selective laser excitation with both Fourier transform and CW EPR spectroscopies. It is shown that the electron transfer occurs from the singlet state of the porphyrin constituent to produce the terminal benzoquinone radical anion and the carotenoid radical cation. This tetrad molecule can maintain the charge-separated state for a substantial period of time (∼ 1 μs), allowing the characterization of the short-lived radicals. The derivative-like spectrum of the quinone radical anion and its dependence on the turning angle of the microwave pulse indicates that electron transfer proceeds via the singlet state.

AB - Intramolecular electron transfer from the photoexcited state of a carotenoid-porphyrin-diquinone tetrad was studied by selective laser excitation with both Fourier transform and CW EPR spectroscopies. It is shown that the electron transfer occurs from the singlet state of the porphyrin constituent to produce the terminal benzoquinone radical anion and the carotenoid radical cation. This tetrad molecule can maintain the charge-separated state for a substantial period of time (∼ 1 μs), allowing the characterization of the short-lived radicals. The derivative-like spectrum of the quinone radical anion and its dependence on the turning angle of the microwave pulse indicates that electron transfer proceeds via the singlet state.

UR - http://www.scopus.com/inward/record.url?scp=11944263449&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=11944263449&partnerID=8YFLogxK

M3 - Article

AN - SCOPUS:11944263449

VL - 112

SP - 6477

EP - 6481

JO - Journal of the American Chemical Society

JF - Journal of the American Chemical Society

SN - 0002-7863

IS - 18

ER -