title: Non-conjugated, phenyl assisted coupling in through bond electron transfer in a perylenemonoimide-triphenylamine system.
abstract: Two donor-bridge-acceptor compounds containing triphenylamine (TPA) donors and perylenemonoimide (PMI) acceptors have been studied by spectroscopic techniques and quantum chemical computation. Both systems have been observed to emit prompt and delayed fluorescence under certain conditions indicating that forward and reverse electron transfer (ET) processes can occur between the locally excited and the charge separated states. The experimental and computational results show that the TPA and PMI chromophores are better coupled by almost 50% in the meta isomers which undergo ET more readily than the para isomers. Quantum chemical calculations indicate that this unexpected situation is the result of a phenyl group on the side of the bridge being advantageously positioned in the meta isomers. This leads to more extensive delocalisation of the TPA HOMO into the bridge enhancing the total through bond electronic coupling between the TPA and PMI chromophores. The calculations also indicate a strong angle dependence of the total coupling in both isomers. The experimental results are discussed in the context of the high temperature limit of Marcus's theory of non-adiabatic ET.
authors.affiliation: Department of Chemistry, Katholieke Universiteit Leuven, Insitute for Nanoscale Physics and Chemistry, Celestijnenlaan 200F, 3001, Heverlee, Belgium.
authors.forename: Toby D M
authors.initials: TD
authors.lastname: Bell
authors.forename: Alina
authors.initials: A
authors.lastname: Stefan
authors.forename: Vincent
authors.initials: V
authors.lastname: Lemaur
authors.forename: Stefan
authors.initials: S
authors.lastname: Bernhardt
authors.forename: Klaus
authors.initials: K
authors.lastname: Müllen
authors.forename: Jérôme
authors.initials: J
authors.lastname: Cornil
authors.forename: David
authors.initials: D
authors.lastname: Beljonne
authors.forename: Johan
authors.initials: J
authors.lastname: Hofkens
authors.forename: Mark
authors.initials: M
authors.lastname: Van der Auweraer
authors.forename: Frans C
authors.initials: FC
authors.lastname: De Schryver
mesh_terms: D003198:Computer Simulation; D004159:Diphenylamine / Q000031:analogs & derivatives* / Q000737:chemistry*; D004583:Electrons; D015394:Molecular Structure; D010569:Perylene / Q000031:analogs & derivatives* / Q000737:chemistry*; D011789:Quantum Theory; D013696:Temperature
chemical_list: D010569:Perylene; D004159:Diphenylamine