Efficient intramolecular energy transfer in single endcapped conjugated polymer molecules in the absence of appreciable spectral overlap

Klaus Becker; John M Lupton; Jochen Feldmann; Sepas Setayesh; Andrew C Grimsdale; Klaus Müllen

doi:10.1021/ja056469h

Efficient intramolecular energy transfer in single endcapped conjugated polymer molecules in the absence of appreciable spectral overlap

J Am Chem Soc. 2006 Jan 25;128(3):680-1. doi: 10.1021/ja056469h.

Authors

Klaus Becker¹, John M Lupton, Jochen Feldmann, Sepas Setayesh, Andrew C Grimsdale, Klaus Müllen

Affiliation

¹ Photonics and Optoelectronics Group, Department of Physics and CeNS, Ludwig-Maximilians-Universität, Munich, Germany.

PMID: 16417332
DOI: 10.1021/ja056469h

Abstract

Intramolecular energy transfer is investigated in an endcapped conjugated polymer on the single molecule level at low temperature. While light harvesting in one dimension is on average inefficient in the ensemble, the efficiency scatters widely on the single molecule level, with some molecules exhibiting near-unity transfer probability from the polymer backbone donor to the acceptor endcap. This transfer occurs in the absence of spectral overlap between donor and acceptor, as the electronic and vibronic transitions narrow substantially at low temperatures once inhomogeneous disorder broadening is overcome. The results illustrate how far-field absorption and emission characteristics of molecular transitions are insufficient to describe resonant energy transfer processes following Förster theory in multichromophoric aggregates. Rather, exciton trapping due to efficient multiphonon emission has to be invoked with a possible contribution of strong polaronic coupling.