Probing molecular properties and the role of the environment at the single-molecule level

Hofkens, J.; Bell, T. D. M.; Stefan, A.; Fron, E.; Müllen, K.; De Schryver, F. C.

doi:10.1351/pac200678122261

Pure Appl. Chem., 2006, Vol. 78, No. 12, pp. 2261-2266

http://dx.doi.org/10.1351/pac200678122261

Probing molecular properties and the role of the environment at the single-molecule level

J. Hofkens¹, T. D. M. Bell¹, A. Stefan¹, E. Fron¹, K. Müllen² and F. C. De Schryver¹

¹ Department of Chemistry, Katholieke Universiteit Leuven, Celestijnenlaan 200F, 3001 Heverlee, Belgium
² Max-Planck-Institut für Polymerforschung, Ackermannweg 10, D-55128 Mainz, Germany

Abstract: Evidence for intramolecular photoinduced electron transfer (ET) in synthetic systems consisting of a triphenylamine-perylenediimide donor-acceptor dendrimer or a triphenylamine-peryleneimide dendrimer at the ensemble and single-molecule (SM) level is presented. Moreover, for the first time a direct observation of the forward as well as the backward ET step is made in a single emitting entity. Fluctuations in the values of the rate constants for forward and backward ET were observed, induced by the local environment as well as by conformational changes of the dendrimer itself. The results obtained in a weakly coupled system can also be extended to a strongly coupled donor-acceptor system based on peryleneimide and penta-phenylene.