“Lock and Key Control” of Photochromic Reactivity by Controlling the Oxidation/Reduction State

A photochemical active triangle terarylene was synthesized and the photochromic behavior was investigated. Its photochromic reactivity can be strongly suppressed by selected oxidization of the sulfur atoms in the molecules. Reactivated photochromic reactivity was obtained by deoxidization of the S,S-dioxide moieties. The suppressed photoactivity of the oxidation state was attributed to the stronger intramolecular hydrogen bonding interactions.