Syntheses and optoelectronic properties of four photochromic dithienylethenes

Photochromic dithienylethene 1a, 2a, 3a and 4a were synthesized, and their optoelectronic properties, such as photochromism in solution as well as in poly-methylmethacrylate (PMMA) amorphous films, fluorescence and electrochemical properties were investigated in detail.