6533b7d5fe1ef96bd1265395

RESEARCH PRODUCT

Superexchange-mediated electronic energy transfer in a model dyad

Josemon JacobBenedetta MennucciKlaus MüllenBernard Van AverbekeBernard Van AverbekeCarles CurutchetDavid BeljonneThomas BaschéFlorian A. Feist

subject

StereochemistryGeneral Physics and AstronomyChromophorePolarizable continuum modelAcceptorchemistry.chemical_compoundPartial chargechemistrySuperexchangeChemical physicsExcited stateDensity functional theoryPhysical and Theoretical ChemistryPerylene

description

On 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 approximately 3-fold increase in the electronic interaction between the chromophores, which explains the failure of the Förster 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.

https://doi.org/10.1039/c003496g