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Buckycatcher. A New Opportunity for Charge-Transfer Mediation?

This contribution deals with a computational study of hole transfer (HT) and excess electron transfer (EET) in complexes of a buckyball and a molecular catcher having two concave buckybowls as described by Sygula et al. (J. Am. Chem. Soc. 2007, 129, 3842). Three systems are considered:  (1) the inclusion complex consisting of the fullerene and catcher subunits, (2) a system formed by two catchers, and (3) a supermolecular system consisting of two fullerene and two catcher molecules. Such a type of organic system is of potential interest in the design of nanoelectronic devices. HT and EET electronic couplings of the subunits in the systems are calculated using the HF/6-31G* method and the semiempirical INDO/S scheme; the calculation of the reorganization energy is carried out within the B3LYP/6-31G* method. On the basis of the computed values of electronic couplings and reorganization energies, we predict that excess charge (hole or electron) should be strongly confined to a single subunit in the complexes. Then, we suggest that excess charge propagation within the fullerene-catcher system in the solid state occurs as superexchange mediated hopping; in this process, fullerene molecules function as stepping stones, while the catcher effectively mediates the charge transport between buckyballs. The properties of the buckycatcher, acting as a charge-transfer mediator from and to fullerenes, are found to be quite different for electron- and hole-transfer processes. We estimate the absolute rate of the hole and the excess electron hopping between fullerenes, kHT = 1.28 1012 s-1, while kEET = 1.07 109 s-1 and find that the HT is much faster than the EET because of (1) the stronger HT coupling between neighboring buckybowls of the catchers and (2) the smaller HT reorganization energy relative to that for EET

This work has been supported by Project No. CTQ2005-04563 of the Spanish Ministerio de Educación y Ciencia (MEC)

© Journal of Physical Chemistry C, 2008, vol. 112, núm. 5, p. 1672-1678

American Chemical Society (ACS)

Author: Voityuk, Alexander A.
Duran i Portas, Miquel
Date: 2008
Abstract: This contribution deals with a computational study of hole transfer (HT) and excess electron transfer (EET) in complexes of a buckyball and a molecular catcher having two concave buckybowls as described by Sygula et al. (J. Am. Chem. Soc. 2007, 129, 3842). Three systems are considered:  (1) the inclusion complex consisting of the fullerene and catcher subunits, (2) a system formed by two catchers, and (3) a supermolecular system consisting of two fullerene and two catcher molecules. Such a type of organic system is of potential interest in the design of nanoelectronic devices. HT and EET electronic couplings of the subunits in the systems are calculated using the HF/6-31G* method and the semiempirical INDO/S scheme; the calculation of the reorganization energy is carried out within the B3LYP/6-31G* method. On the basis of the computed values of electronic couplings and reorganization energies, we predict that excess charge (hole or electron) should be strongly confined to a single subunit in the complexes. Then, we suggest that excess charge propagation within the fullerene-catcher system in the solid state occurs as superexchange mediated hopping; in this process, fullerene molecules function as stepping stones, while the catcher effectively mediates the charge transport between buckyballs. The properties of the buckycatcher, acting as a charge-transfer mediator from and to fullerenes, are found to be quite different for electron- and hole-transfer processes. We estimate the absolute rate of the hole and the excess electron hopping between fullerenes, kHT = 1.28 1012 s-1, while kEET = 1.07 109 s-1 and find that the HT is much faster than the EET because of (1) the stronger HT coupling between neighboring buckybowls of the catchers and (2) the smaller HT reorganization energy relative to that for EET
This work has been supported by Project No. CTQ2005-04563 of the Spanish Ministerio de Educación y Ciencia (MEC)
Format: application/pdf
ISSN: 1932-7447 (versió paper)
1932-7455 (versió electrònica)
Document access: http://hdl.handle.net/10256/12199
Language: eng
Publisher: American Chemical Society (ACS)
Collection: MEC/PN 2005-2008/CTQ2005-04563
Reproducció digital del document publicat a: http://dx.doi.org/10.1021/jp075209e
Articles publicats (D-Q)
Is part of: © Journal of Physical Chemistry C, 2008, vol. 112, núm. 5, p. 1672-1678
Rights: Tots els drets reservats
Subject: Electrons -- Transport
Electron transport
Transferència de càrrega
Charge transfer
Title: Buckycatcher. A New Opportunity for Charge-Transfer Mediation?
Type: info:eu-repo/semantics/article
Repository: DUGiDocs

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