Switchable 2,3-dithienylmaleimide bonded to different fluorophores： synthesis and photochromic properties

A series of photochromic diarylethene derivatives containing different fluorophores was synthesized by the Sonogashira coupling reaction and characterized by ^1H nuclear magnetic resonance （NMR）, ^13C NMR and mass spectroscopy. Photochromic conversion of Cz-MS was observed and its structural change was confirmed by proton NMR, Switchable absorption and emission phenomena were observed for these molecules. These phenomena were attributed to the reversible photochromic fluorescence resonance energy transfer （pcFRET） process. The design of this novel photochromic system of Py-4MS enables information to be processed in a non-destructive manner. This overcomes the problem of the destructive nature of tracking photochromism using ultraviolet （UV）-vis spectroscopy.