Photoinduced charge separation in a carotenoid-porphyrin-diquinone tetrad

enhancement of quantum yields via control of electronic coupling

Seung Joo Lee, Janice M. DeGraziano, Alisdair N. Macpherson, Eun Ju Shin, Pamela K. Kerrigan, Gilbert R. Seely, Ana L Moore, Thomas A Moore, John Devens Gust

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

A molecular tetrad consisting of a free-base porphyrin (P) linked to a carotenoid polyene (C) and a diquinone moiety (QA-QB) has been synthesized, and its photochemistry has been investigated using time-resolved techniques. Excitation of the porphyrin moiety of the tetrad in dichloromethane solution is followed by photoinduced electron transfer to yield an initial C-P{radical dot}+-Q{radical dot}-A-QB state, which is formed with arate constant of 2.3×109 s-1 and a quantum yield of 0.87. In chloroform, the rate is 4.1×109 s-1 and the quantum yield is 0.94. Transient absorption studies show that this state evolves by subsequent electron transfer pathways to a final C{radical dot}+-P-QA-Q{radical dot}-B charge-separated state whose lifetime is 7.4 μs in dichloromethane and 740 ns in chloroform. The quantum yield of the final state is 0.49 in dichloromethane and 0.57 in chloroform. The yield of the final state is substantially higher than that in a related, previously-reported tetrad in spite of the fact that the quantum yield of the initial C-P{radical dot}+-Q{radical dot}-A-QB species is lower. This fact is interpreted in terms of the rates of charge-separation reactions relative to those of charge recombination. It is shown that yields of charge separation in multicomponent molecules may be altered in a predictable fashion using the basic tenets of electron transfer theory.

Original languageEnglish
Pages (from-to)321-336
Number of pages16
JournalChemical Physics
Volume176
Issue number2-3
DOIs
Publication statusPublished - Oct 15 1993

Fingerprint

carotenoids
Porphyrins
Quantum yield
Carotenoids
polarization (charge separation)
porphyrins
Methylene Chloride
Chloroform
augmentation
chloroform
electronics
Electrons
electron transfer
Polyenes
Photochemical reactions
photochemical reactions
Molecules
life (durability)
excitation
molecules

ASJC Scopus subject areas

  • Physical and Theoretical Chemistry
  • Spectroscopy
  • Atomic and Molecular Physics, and Optics

Cite this

Photoinduced charge separation in a carotenoid-porphyrin-diquinone tetrad : enhancement of quantum yields via control of electronic coupling. / Lee, Seung Joo; DeGraziano, Janice M.; Macpherson, Alisdair N.; Shin, Eun Ju; Kerrigan, Pamela K.; Seely, Gilbert R.; Moore, Ana L; Moore, Thomas A; Gust, John Devens.

In: Chemical Physics, Vol. 176, No. 2-3, 15.10.1993, p. 321-336.

Research output: Contribution to journalArticle

Lee, Seung Joo ; DeGraziano, Janice M. ; Macpherson, Alisdair N. ; Shin, Eun Ju ; Kerrigan, Pamela K. ; Seely, Gilbert R. ; Moore, Ana L ; Moore, Thomas A ; Gust, John Devens. / Photoinduced charge separation in a carotenoid-porphyrin-diquinone tetrad : enhancement of quantum yields via control of electronic coupling. In: Chemical Physics. 1993 ; Vol. 176, No. 2-3. pp. 321-336.
@article{d941ee6502344dc684ad555cd2960786,
title = "Photoinduced charge separation in a carotenoid-porphyrin-diquinone tetrad: enhancement of quantum yields via control of electronic coupling",
abstract = "A molecular tetrad consisting of a free-base porphyrin (P) linked to a carotenoid polyene (C) and a diquinone moiety (QA-QB) has been synthesized, and its photochemistry has been investigated using time-resolved techniques. Excitation of the porphyrin moiety of the tetrad in dichloromethane solution is followed by photoinduced electron transfer to yield an initial C-P{radical dot}+-Q{radical dot}-A-QB state, which is formed with arate constant of 2.3×109 s-1 and a quantum yield of 0.87. In chloroform, the rate is 4.1×109 s-1 and the quantum yield is 0.94. Transient absorption studies show that this state evolves by subsequent electron transfer pathways to a final C{radical dot}+-P-QA-Q{radical dot}-B charge-separated state whose lifetime is 7.4 μs in dichloromethane and 740 ns in chloroform. The quantum yield of the final state is 0.49 in dichloromethane and 0.57 in chloroform. The yield of the final state is substantially higher than that in a related, previously-reported tetrad in spite of the fact that the quantum yield of the initial C-P{radical dot}+-Q{radical dot}-A-QB species is lower. This fact is interpreted in terms of the rates of charge-separation reactions relative to those of charge recombination. It is shown that yields of charge separation in multicomponent molecules may be altered in a predictable fashion using the basic tenets of electron transfer theory.",
author = "Lee, {Seung Joo} and DeGraziano, {Janice M.} and Macpherson, {Alisdair N.} and Shin, {Eun Ju} and Kerrigan, {Pamela K.} and Seely, {Gilbert R.} and Moore, {Ana L} and Moore, {Thomas A} and Gust, {John Devens}",
year = "1993",
month = "10",
day = "15",
doi = "10.1016/0301-0104(93)80243-3",
language = "English",
volume = "176",
pages = "321--336",
journal = "Chemical Physics",
issn = "0301-0104",
publisher = "Elsevier",
number = "2-3",

}

TY - JOUR

T1 - Photoinduced charge separation in a carotenoid-porphyrin-diquinone tetrad

T2 - enhancement of quantum yields via control of electronic coupling

AU - Lee, Seung Joo

AU - DeGraziano, Janice M.

AU - Macpherson, Alisdair N.

AU - Shin, Eun Ju

AU - Kerrigan, Pamela K.

AU - Seely, Gilbert R.

AU - Moore, Ana L

AU - Moore, Thomas A

AU - Gust, John Devens

PY - 1993/10/15

Y1 - 1993/10/15

N2 - A molecular tetrad consisting of a free-base porphyrin (P) linked to a carotenoid polyene (C) and a diquinone moiety (QA-QB) has been synthesized, and its photochemistry has been investigated using time-resolved techniques. Excitation of the porphyrin moiety of the tetrad in dichloromethane solution is followed by photoinduced electron transfer to yield an initial C-P{radical dot}+-Q{radical dot}-A-QB state, which is formed with arate constant of 2.3×109 s-1 and a quantum yield of 0.87. In chloroform, the rate is 4.1×109 s-1 and the quantum yield is 0.94. Transient absorption studies show that this state evolves by subsequent electron transfer pathways to a final C{radical dot}+-P-QA-Q{radical dot}-B charge-separated state whose lifetime is 7.4 μs in dichloromethane and 740 ns in chloroform. The quantum yield of the final state is 0.49 in dichloromethane and 0.57 in chloroform. The yield of the final state is substantially higher than that in a related, previously-reported tetrad in spite of the fact that the quantum yield of the initial C-P{radical dot}+-Q{radical dot}-A-QB species is lower. This fact is interpreted in terms of the rates of charge-separation reactions relative to those of charge recombination. It is shown that yields of charge separation in multicomponent molecules may be altered in a predictable fashion using the basic tenets of electron transfer theory.

AB - A molecular tetrad consisting of a free-base porphyrin (P) linked to a carotenoid polyene (C) and a diquinone moiety (QA-QB) has been synthesized, and its photochemistry has been investigated using time-resolved techniques. Excitation of the porphyrin moiety of the tetrad in dichloromethane solution is followed by photoinduced electron transfer to yield an initial C-P{radical dot}+-Q{radical dot}-A-QB state, which is formed with arate constant of 2.3×109 s-1 and a quantum yield of 0.87. In chloroform, the rate is 4.1×109 s-1 and the quantum yield is 0.94. Transient absorption studies show that this state evolves by subsequent electron transfer pathways to a final C{radical dot}+-P-QA-Q{radical dot}-B charge-separated state whose lifetime is 7.4 μs in dichloromethane and 740 ns in chloroform. The quantum yield of the final state is 0.49 in dichloromethane and 0.57 in chloroform. The yield of the final state is substantially higher than that in a related, previously-reported tetrad in spite of the fact that the quantum yield of the initial C-P{radical dot}+-Q{radical dot}-A-QB species is lower. This fact is interpreted in terms of the rates of charge-separation reactions relative to those of charge recombination. It is shown that yields of charge separation in multicomponent molecules may be altered in a predictable fashion using the basic tenets of electron transfer theory.

UR - http://www.scopus.com/inward/record.url?scp=0010896331&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0010896331&partnerID=8YFLogxK

U2 - 10.1016/0301-0104(93)80243-3

DO - 10.1016/0301-0104(93)80243-3

M3 - Article

VL - 176

SP - 321

EP - 336

JO - Chemical Physics

JF - Chemical Physics

SN - 0301-0104

IS - 2-3

ER -