Abstract
Quantum-chemical techniques are applied to model the mechanisms of photoinduced charge transfer from a π-electron donating group (tetracene, D) to a π-electron-acceptor moiety (pyromellitimide, A) separated by a bridge of increasing size (p-phenylenevinylene oligomers, B). Correlated Hartree-Fock semiempirical approaches are exploited to calculate the four main parameters controlling the transfer rate (kRP) in the framework of Marcus-Jortner-Levich's formalism: (i) the electronic coupling between the initial and final states; (ii) and (iii) the internal and external reorganization energy terms; and (iv) the variation of the free Gibbs energy. The charge transfer is shown to proceed in these compounds through two competing mechanisms, coherent (superexchange) versus incoherent (bridge-mediated) pathways. While superexchange is the dominant mechanism for short bridges, incoherent transfer through hopping along the phenylene vinylene segment takes over in longer chains (for ca. three phenylenevinylene repeat units). The influence of the chemical structure of the π-conjugated phenylenevinylene bridge on the electronic properties and the rate of charge transfer is also investigated.
| Original language | English |
|---|---|
| Pages (from-to) | 4436-4447 |
| Number of pages | 12 |
| Journal | Journal of the American Chemical Society |
| Volume | 124 |
| Issue number | 16 |
| DOIs | |
| Publication status | Published - Apr 24 2002 |
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ASJC Scopus subject areas
- Chemistry(all)
Cite this
Photoinduced electron-transfer processes along molecular wires based on phenylenevinylene oligomers : A quantum-chemical insight. / Pourtois, G.; Beljonne, D.; Cornil, J.; Ratner, Mark A; Brédas, J. L.
In: Journal of the American Chemical Society, Vol. 124, No. 16, 24.04.2002, p. 4436-4447.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Photoinduced electron-transfer processes along molecular wires based on phenylenevinylene oligomers
T2 - A quantum-chemical insight
AU - Pourtois, G.
AU - Beljonne, D.
AU - Cornil, J.
AU - Ratner, Mark A
AU - Brédas, J. L.
PY - 2002/4/24
Y1 - 2002/4/24
N2 - Quantum-chemical techniques are applied to model the mechanisms of photoinduced charge transfer from a π-electron donating group (tetracene, D) to a π-electron-acceptor moiety (pyromellitimide, A) separated by a bridge of increasing size (p-phenylenevinylene oligomers, B). Correlated Hartree-Fock semiempirical approaches are exploited to calculate the four main parameters controlling the transfer rate (kRP) in the framework of Marcus-Jortner-Levich's formalism: (i) the electronic coupling between the initial and final states; (ii) and (iii) the internal and external reorganization energy terms; and (iv) the variation of the free Gibbs energy. The charge transfer is shown to proceed in these compounds through two competing mechanisms, coherent (superexchange) versus incoherent (bridge-mediated) pathways. While superexchange is the dominant mechanism for short bridges, incoherent transfer through hopping along the phenylene vinylene segment takes over in longer chains (for ca. three phenylenevinylene repeat units). The influence of the chemical structure of the π-conjugated phenylenevinylene bridge on the electronic properties and the rate of charge transfer is also investigated.
AB - Quantum-chemical techniques are applied to model the mechanisms of photoinduced charge transfer from a π-electron donating group (tetracene, D) to a π-electron-acceptor moiety (pyromellitimide, A) separated by a bridge of increasing size (p-phenylenevinylene oligomers, B). Correlated Hartree-Fock semiempirical approaches are exploited to calculate the four main parameters controlling the transfer rate (kRP) in the framework of Marcus-Jortner-Levich's formalism: (i) the electronic coupling between the initial and final states; (ii) and (iii) the internal and external reorganization energy terms; and (iv) the variation of the free Gibbs energy. The charge transfer is shown to proceed in these compounds through two competing mechanisms, coherent (superexchange) versus incoherent (bridge-mediated) pathways. While superexchange is the dominant mechanism for short bridges, incoherent transfer through hopping along the phenylene vinylene segment takes over in longer chains (for ca. three phenylenevinylene repeat units). The influence of the chemical structure of the π-conjugated phenylenevinylene bridge on the electronic properties and the rate of charge transfer is also investigated.
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U2 - 10.1021/ja017150+
DO - 10.1021/ja017150+
M3 - Article
VL - 124
SP - 4436
EP - 4447
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
SN - 0002-7863
IS - 16
ER -