We have synthesized three diarylethene derivatives - 1,2-bis(2-(4-n-alkylphenyl)benzofuran-3-yl)ethenes (1a-3a). we have observed the morphology changes of the melted diarylethenes after heating. The crystal of 2a melts at 102 degrees C. After heating at 130 degrees C, the liquid did not crystallize below 40 degrees C for more than 3 days because of the temperature above the eutectic point. When the liquid was irradiated with 365 nm light, the photoirradiated area crystallized, because of the generation of 2b. After the sample was irradiated with visible light, the crystals changed to a colorless liquid. Photoinduced crystallization was also observed for the 4-n-clodecyl derivative (3a). (C) 2010 Elsevier B.V. All rights reserved.