Photochromism of a diarylethene derivative in aqueous solution capping with a water-soluble nano-cavitand

A photochromic diarylethene, 1,2-bis(3-methyl-2-thienyl)perfluorocyclopentene (1) was encapsulated into water-soluble nano-cavitand 2 to induce the photochromic performance in aqueous solution. 1H NMR measurements confirmed the formation of 1:1 complex between 1 and 2 in a D2O solution. Upon irradiation with UV and visible light, encapsulated diarylethene within nano-cavitand exhibited reversible and efficient photochromic reactions even in the aqueous solution. The photocyclization and photocycloreversion quantum yields are almost similar to those observed in organic solvents. The efficient photochromic performance of the diarylethene in aqueous solution is attributed to the fact that the empty pore of 2 selectively captures the hydrophobic perfluorocyclopentene moiety and the reactive thiophene moieties are free from the cavity, as evidenced by 1H NOESY measurement.