Photoswitching of an alcohol-sensitive photochromic diarylethene

Article abstract of DOI:10.1016/j.tetlet.2011.02.039

The closed-ring isomer of diarylethene 1a, 1-(2-methyl-5-(4-N,N- diethylaminophenyl)thien-3-yl)-2-(2-methyl-5-phenylthien-3-yl) perfluorocyclopentene was found to cause the substitution reaction with primary alcohols at room temperature. The open-ring isomer 1a was stable in the alcohols. The product obtained in methanol was isolated by HPLC, and the structure was identified by ¹H NMR, mass spectrometry, and X-ray crystallographic analysis. It was revealed that two fluorine atoms were replaced with methoxy groups. The substitution reaction was also caused with ethylene glycol to form the five-membered ring. Both the products also showed photochromism, and had absorption maxima and photocycloreversion quantum yields different from those of 1a.