title: Photoinduced electron transfer of zinc porphyrin-oligo(thienylenevinylene)-fullerene[60] triads; thienylenevinylenes as efficient molecular wires.
abstract: Two novel donor-bridge-acceptor arrays (ZnP-nTV-C60) with zinc porphyrin (ZnP) and fullerene (C60), covalently connected by oligo(thienylenevinylene) (nTV) molecular wires (n = 3 and 8; ), have been prepared in a multistep convergent manner. The influence of the nTV-length on the electrochemical and electronic properties of the ZnP-nTV-C60 triads has been revealed. Interestingly, an efficient photoinduced electron transfer process occurs in both triads with formation of intermediate radical-ion pairs (namely, ZnP˙(+)-nTV-C60˙(-) and ZnP-nTV˙(+)-C60˙(-)) as confirmed by the nanosecond transient absorption measurements in the visible and NIR regions. In polar and nonpolar solvents, the rate constants of charge-separation processes (kCS) via(1)ZnP*-nTV-C60 were found to decrease from ca. 1.2 × 10(10) s(-1) for n = 3 (RDA = 20 Å) to (5-7) × 10(9) s(-1) for n = 8 (RDA = 60 Å) on the basis of fluorescence lifetime measurements of the ZnP moiety. From these data, together with those previously obtained ones for n = 4 in the related ZnP-nTV-C60 systems, a low attenuation coefficient was evaluated for the nTV molecular wires.
authors.affiliation: Instituto de Nanociencia Nanotecnología y Materiales Moleculares (INAMOL), Universidad de Castilla-La Mancha, 45071-Toledo, Spain. Fernando.Langa@uclm.es.
authors.forename: Frédéric
authors.initials: F
authors.lastname: Oswald
authors.forename: D-M Shafiqul
authors.initials: DM
authors.lastname: Islam
authors.forename: Mohamed E
authors.initials: ME
authors.lastname: El-Khouly
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Araki
authors.forename: Rubén
authors.initials: R
authors.lastname: Caballero
authors.forename: Pilar
authors.initials: P
authors.lastname: de la Cruz
authors.forename: Osamu
authors.initials: O
authors.lastname: Ito
authors.forename: Fernando
authors.initials: F
authors.lastname: Langa