Integrating molecular switching and chemical reactivity using photoresponsive hexatrienes*
Hema D. Samachetty and Neil R. Branda
Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, British Columbia, Canada
Abstract: The use of photoresponsive hexatriene architectures to regulate chemical reactivity is described. The major focus of this report is how the two isomers of dithienylethene derivatives exhibit different steric and electronic properties. The ring-open form is structurally flexible, and the thiophene rings are electronically insulated from each other, while the ring-closed counterpart has a rigid structure, and there is a linear π-conjugated pathway along the molecular backbone. Representative examples that demonstrate how these photoswitches can be used to influence metal coordination, catalysis, and nucleophilicity are highlighted in this overview.
Keywords: molecular switches; photochromism; photochemistry; dithienylethenes; hexatrienes.
*Paper based on a presentation at the XXIst Symposium on Photochemistry, 2-7 April 2006, Kyoto, Japan. Other presentations are published in this issue, pp. 2193-2359.