Cold crystallization and photo-induced thermal behavior of alkyl-derivatized diarylethene molecules.

The thermal behavior of alkylated diarylethene molecules (2,3-bis(2,4,5-trimethyl-3-thienyl)--alkylmaleimides; DAE-C) was investigated. DAE-C1 and DAE-C2 exhibited cold crystallization, which is a heat-storage phenomenon. In addition, DAE-C showed photoisomerization; the open-ring isomer O-DAE-C was formed by visible light irradiation and transformed to the closed-ring isomer C-DAE-C by UV light irradiation.