Superexchange-mediated electronic energy transfer in a model dyad

TitleSuperexchange-mediated electronic energy transfer in a model dyad
Publication TypeJournal Article
Year of Publication2010
AuthorsCurutchet, C, Feist FA, Van Averbeke B, Mennucci B, Jacob J, Muellen K, Basche T, Beljonne D
JournalPhysical Chemistry Chemical Physics
Pagination7378 - 7385
Date Published2010
ISBN Number1463-9076
Keywordsanisotropic dielectrics, conjugated polymers, continuum, Dynamics, excitation, ionic-solutions, molecule fluorescence spectroscopy, scale interpretation, solvated bichromophoric systems, through-bond
AbstractOn the basis of time-dependent density functional theory (TD-DFT) calculations coupled to the polarizable continuum model (PCM) and single molecule spectroscopic studies, we provide a detailed investigation of excitation energy transfer within a model bi-chromophoric system where a perylene monoimide (PMI) donor is bridged to a terrylene diimide (TDI) acceptor through a ladder-type pentaphenylene (pPh) spacer. We find that the electronic excitation on the PMI donor significantly extends over the bridge giving rise to a partial charge transfer character and inducing a similar to 3-fold increase in the electronic interaction between the chromophores, which explains the failure of the Forster model in reproducing the observed energy migration rates when treating PMI as the donor. However, despite an increased charge transfer contribution in the effective donor state, the increase in solvent polarity is not accompanied by an enhancement in the electronic coupling between the subunits, which is rationalized from a detailed analysis of the excited-state wavefunctions.