Visible-Light-Dependent Photocyclization: Design, Synthesis, and Properties of a Cyanine-Based Dithienylethene

A cyanine-based dithienylethene is developed. Its photoisomerization shows that (1) the irradiation of visible light can induce cyclization while the cycloreversion takes place upon irradiation with UV light and (2) the addition of CN– can lead to cyclization and cycloreversion upon irradiation of UV light and visible light, respectively.