title: Very fast single-step photoinduced charge separation in zinc porphyrin bridged to a gold porphyrin by a bisethynyl quaterthiophene.
abstract: A new heterometallic dyad composed of a zinc porphyrin linked by bisethynyl quaterthiophene to a gold porphyrin was synthesized according to a stepwise modular approach. The latter dyad and the parent reference compounds (porphyrin-ethynylquaterthiophene) were characterized by electrochemistry, spectroelectrochemistry, and femtosecond transient absorption spectrocopy. We showed that light excitation of the zinc or the gold porphyrin induces a very fast and quantitative charge separation over a distance of 25 A which occurs through a superexchange mechanism. The lifetime of the charge-separated state is 3.3 ns in toluene and 100 ps in dichloromethane, and it recombines to the ground state in both solvents.
authors.affiliation: Universite de Nantes, Chimie Et Interdisciplinarite, Synthese, Analyse, Modelisation, Faculte des Sciences et des Techniques, 2, rue de la Houssiniere, BP 92208, 44322 Nantes Cedex 3, France.
authors.forename: Jérôme
authors.initials: J
authors.lastname: Fortage
authors.forename: Julien
authors.initials: J
authors.lastname: Boixel
authors.forename: Errol
authors.initials: E
authors.lastname: Blart
authors.forename: Hans Christian
authors.initials: HC
authors.lastname: Becker
authors.forename: Fabrice
authors.initials: F
authors.lastname: Odobel