Multicolor Photochromism of Two- and Three-Component Diarylethene Crystals

Novel photochromic single crystals composed of three different kinds of diarylethenes, 1,2-bis(3,5-dimethyl-2-thienyl)perfluorocyclopentene (1a), 1,2-bis(2,5-dimethyl-3-thienyl)perfluorocyclopentene (2a),
and 1,2-bis(2-methyl-5-p-methoxyphenyl-3-thienyl)perfluorocyclopentene (3a), have been prepared. The
three-component crystals turned yellow, orange, red, purple, blue, green, or black upon irradiation with
light of appropriate wavelengths. The colors of the crystals were thermally stable in the dark and completely
bleached by irradiation with visible light. Such multicolored photochromic crystals have potential for the
application to optoelectronic devices, such as multifrequency three-dimensional optical memory media or
full-color displays.