title: Two-photon photochromism of diarylethene dimer derivatives.
abstract: Photochromic diarylethene dimer derivatives with large two-photon absorption (TPA) cross-sections have been designed and synthesized. The derivatives have a D-pi-D structure in which indole rings are used as donor units (D) and 1,4-bis(ethynyl)benzene or 1,4-bis(ethenyl)benzene as a pi-conjugated chain unit (pi). Compound 5 a, which has oxazole rings as one of the aryl groups, showed a TPA cross-section of 23 GM at 820 nm and exhibited efficient two-photon photochromic reactivity.
authors.affiliation: Department of Chemistry and Biochemistry, Graduate School of Engineering, Kyushu University, Hakozaki 6-10-1 Higashi-ku, Fukuoka 812-8581, Japan.
authors.forename: Shingo
authors.initials: S
authors.lastname: Saita
authors.forename: Tadatsugu
authors.initials: T
authors.lastname: Yamaguchi
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Kawai
authors.forename: Masahiro
authors.initials: M
authors.lastname: Irie