Fulgides as Light Switches for Intra-Supermolecular Energy Transfer

Abstract

Photochromic fulgides undergo reversible color change upon irradiation with UV/VIS light. This is due to electrocyclic ring closure/ring opening. On addition of substituents, the fulgides examined retain their photochromic behavior; however, their photophysical properties, i.e. reaction quantum yields and fluorescence properties, are altered. The photoswitching has been analyzed in solid polymer matrix and in vapor deposited thin films. In addition to UV/VIS spectroscopy, IR absorption was used to examine the isomerization reactions. The photochromism of a donor-acceptor substituted thienyl-fulgimide can be used for optical switching of intramolecular energy transfer.