Long-range exchange contribution to singlet-singlet energy transfer in a series of rigid bichromophoric molecules

Oevering, Henk; Verhoeven, J. W.; Paddon‐Row, Michael N.; Cotsaris, E.; Hush, Noel S.

doi:10.1016/0009-2614(88)87401-3

Cited by 121 publications

(66 citation statements)

References 24 publications

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“…A particularly well studied example is aryl to ketone intramolecular singlet-singlet energy transfer (intra-SET)$ (Lamola ef al., 1965;Weinreb and Werner, 1974;Zimmerman et al, 1980;Hassoon et al, 1983Hassoon et al, , 1984Speiser, 1983Speiser, , 1986Morrison et al, 1986;Johnston and Scaiano, 1987;Oevering et al, 1988). Here there is good evidence that intra-SET in compounds such as 1 (Zimmerman et al, 1980) and 2 (Oevering et al, 1988) occurs predominantly via an electron exchange mechanism (see also, Hassoon et al, 1984) as one would expect from the known mechanism of aryl-ketone interrnolecular energy transfer (Janda and Wettack, 1972;Loper and Lee, 1973;Augustyniak et al, 19761 1977). Less attention has been paid to the potential utilization of intra-SET in organic synthesis.…”

Section: Introductionmentioning

confidence: 99%

Photochemistry of Polyfunctional Molecules. Development of Antenna Chromophores for Self‐sensitized Photoreduction of Ketones*

Morrison

1989

Photochem & Photobiology

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–Model systems are reported which test the efficacy of potential aryl antenna groups designed to harvest photons and subsequently transfer electronic energy to a target ketone through singlet‐singlet energy transfer. The model series consists of 4‐aryl substituted cyclohexanones where the aryl groups are benzyloxy (5a), benzoyl (5b), and dimethylphenylsiloxy (5c). In each case, photolysis of isopropyl alcohol solutions of the substrate with 254 nm light results in photoreduction of the ketone to the corresponding alcohols, 6a‐6c. The most efficacious sensitizing antennae are the benzyloxy and dimethylphenylsiloxy chromophores, with quantum efficiencies for reduction equal to 0.57 and 0.48, respectively. Photophysical and photochemical studies on 5a confirm that energy transfer to the ketone is intramolecular with the rate constant for energy transfer estimated at 2.4 × 100 s‐1.

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Section: Introductionmentioning

confidence: 99%

Photochemistry of Polyfunctional Molecules. Development of Antenna Chromophores for Self‐sensitized Photoreduction of Ketones*

Morrison

1989

Photochem & Photobiology

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“…Note, that the interaction of the two chlorophylls, which form the dimer, can have a rather complicated dependence on the distance between them. Namely, the Förster dipoledipole type of interaction for relatively large distances ( 1nm) can be modified for the Dexter mechanism for small distances ( 1nm), which involves the electron exchange interaction [95].…”

Section: Characteristics Of An Lhc Dimermentioning

confidence: 99%

Possible role of interference, protein noise, and sink effects in nonphotochemical quenching in photosynthetic complexes

Berman¹,

Nesterov²,

Gurvitz³

et al. 2016

J. Math. Biol.

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Abstract. We describe a simple and consistent quantum mathematical model that simulates the possible role of quantum interference and sink effects in the nonphotochemical quenching (NPQ) in light-harvesting complexes (LHCs). Our model consists of a network of five interconnected sites (excitonic states) responsible for the NPQ mechanism: (i) Two excited states of chlorophyll molecules, ChlA * and ChlB * , forming an LHC dimer, which is initially populated; (ii) A "damaging" site which is responsible for production of singlet oxygen and other destructive outcomes; (iii) The (ChlA − Zea) * heterodimer excited state (Zea indicates zeaxanthin); and (iv) The charge transfer state of this heterodimer, (ChlA − − Zea + ) * . In our model, both damaging and charge transfer states are described by discrete electron energy levels attached to their sinks, that mimic the continuum part of electron energy spectrum, as at these sites the electron participates in quasi-irreversible chemical reactions. All Possible Role of Interference and Sink Effects . . . 2 five excitonic sites interact with the protein environment that is modeled using a stochastic approach. As an example, we apply our model to demonstrate possible contributions of quantum interference and sink effects in the NPQ mechanism in the CP29 minor LHC. Our numerical results on the quantum dynamics of the reduced density matrix, demonstrate a possible way to significantly suppress, under some conditions, the damaging channel using quantum interference effects and sinks. The results demonstrate the possible role of interference and sink effects for modeling, engineering, and optimizing the performance of the NPQ processes in both natural and artificial light-harvesting complexes.

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“…2.11) and, to be efficient, requires orbital overlap between donor and acceptor. The rate constant for Dexter-type electron exchange ðk D Þ can be expressed in terms of the Fermi Golden rule [103]:…”

Section: Intramolecular Triplet Energy Transfermentioning

confidence: 99%

Electronic Conduction in Photoactive Metallo‐wires

Harriman

Ziessel

2006

Carbon‐Rich Compounds

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Long-range exchange contribution to singlet-singlet energy transfer in a series of rigid bichromophoric molecules

Cited by 121 publications

References 24 publications

Photochemistry of Polyfunctional Molecules. Development of Antenna Chromophores for Self‐sensitized Photoreduction of Ketones*

Photochemistry of Polyfunctional Molecules. Development of Antenna Chromophores for Self‐sensitized Photoreduction of Ketones*

Possible role of interference, protein noise, and sink effects in nonphotochemical quenching in photosynthetic complexes

Electronic Conduction in Photoactive Metallo‐wires

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