title: Modulating charge-transfer interactions in topologically different porphyrin-C60 dyads.
abstract: Control over the interchromophore separation, their angular relationship, and the spatial overlap of their electronic clouds in several ZnP-C(60) dyads (ZnP=zinc porphyrin) is used to modulate the rates of intramolecular electron transfer. For the first time, a detailed analysis of the charge transfer absorption and emission spectra, time-dependent spectroscopic measurements, and molecular dynamics simulations prove quantitatively that the same two moieties can produce widely different electron-transfer regimes. This investigation also shows that the combination of ZnP and C(60) consistently produces charge recombination in the inverted Marcus region, with reorganization energies that are remarkably low, regardless of the solvent polarity. The time constants of electron transfer range from the mus to the ps regime, the electronic couplings from a few tens to several hundreds of cm(-1), and the reorganization energies remain below 0.54 eV and can be as low as 0.16 eV.
authors.affiliation: Radiation Laboratory, University of Notre Dame, Notre Dame, IN 46556, USA. guldi.1@nd.edu
authors.forename: Dirk M
authors.initials: DM
authors.lastname: Guldi
authors.forename: Andreas
authors.initials: A
authors.lastname: Hirsch
authors.forename: Michael
authors.initials: M
authors.lastname: Scheloske
authors.forename: Elke
authors.initials: E
authors.lastname: Dietel
authors.forename: Alessandro
authors.initials: A
authors.lastname: Troisi
authors.forename: Francesco
authors.initials: F
authors.lastname: Zerbetto
authors.forename: Maurizio
authors.initials: M
authors.lastname: Prato