Relaxation pathways and fs dynamics in a photoswitchable intramolecular D -> A energy transfer system

A photoswitchable energy transfer system (donor-switch-acceptor) is examine d in a polymer environment using time-resolved pump and probe spectroscopy. The system consists of a photochromic fulgide derivative acting as switchi ng unit, an anthracene group as energy donor and a coumarin moiety as accep tor. The general value of the concept has already been proven by different spectroscopic methods. To get a deeper insight into the complex energy rela xation process, both the supermolecule and all its subunits are studied sep arately. The role of the switch is analysed by comparing spectra and transi ents of both isomeric forms. (C) 2001 Elsevier Science BN. All rights reser ved.