Construction and properties of multi-addressable switching system based on a photochromic diarylethene

A multi-addressable switching system has been constructed by employing photochromic diarylethene 1a, which is obtained by coupling photochromic 3,4-bis(5-formyl-2-methylthien-3-yl)-2,5-dihydrothiophene with 8-hydroxy-2-methylquinoline, as model compound. It is found that 1a exhibits ring-opening and ring-closing photoisomerization with UV/Vis light irradiation. Addition of trifluoroacetic acid to solution of 1a produces protonated diarylethene 2a, and 2a also performs photochromic behavior with distinguished color change. Both protonated ring-open isomer 2a and ring-closed isomer 2b reverse back to 1a and 1b by neutralization with base solution. Besides, a complex diarylethene 3a is formed when boron trifluoride diethyl etherate is added to a solution of 1a, and it is found that 3a also undergoes excellent photoisomerization.