title: Ultrafast photoinduced charge separation resulting from self-assembly of a green perylene-based dye into pi-stacked arrays.
abstract: Condensation of 3,4,5-tris(n-dodecyloxy)aniline with the green chromophore 1,7-bis(N-pyrrolidinyl)perylene-3,4;9,10-tetracarboxylic dianhydride yields N,N'-bis(3,4,5-tris(n-dodecyloxy)phenyl)-1,7-bis(N-pyrrolidinyl)perylene-3,4;9,10-bis(dicarboximide), 5PDI-TAP, which absorbs light strongly from 550 to 750 nm. 5PDI-TAP dissolves readily in methylcyclohexane (MCH), resulting in self-assembly into H-aggregates. Small-angle X-ray scattering data obtained on 10(-4) M solutions of 5PDI-TAP in MCH show that the aggregates are pi-stacked monodisperse pentamers. Femtosecond transient absorption spectroscopy on solutions of (5PDI-TAP)5 in MCH shows evidence of charge separation occurring with tau < or = 150 fs between adjacent stacked members of 5PDI-TAP within the pentamer followed by charge recombination with tau = 860 ps. Transmission electron microscopy of 5PDI-TAP films cast from solution show isolated bundles of columnar aggregates. (5PDI-TAP)n is a potentially useful material for organic photovoltaics because efficient photoinduced charge generation is an intrinsic property of the assembly.
authors.affiliation: Department of Chemistry and Center for Nanofabrication and Molecular Self-Assembly, Northwestern University, Evanston, Illinois 60208-3113, USA.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Fuller
authors.forename: Louise E
authors.initials: LE
authors.lastname: Sinks
authors.forename: Boris
authors.initials: B
authors.lastname: Rybtchinski
authors.forename: Jovan M
authors.initials: JM
authors.lastname: Giaimo
authors.forename: Xiyou
authors.initials: X
authors.lastname: Li
authors.forename: Michael R
authors.initials: MR
authors.lastname: Wasielewski