title: Synthesis, crystal structure, and photophysical properties of (1E,3E,5E)-1,3,4,6-Tetraarylhexa-1,3,5-trienes: a new class of fluorophores exhibiting aggregation-induced emission.
abstract: Double Horner-Wadsworth-Emmons reaction of (E)-2,3-diaryl-1,4-bis(diethylphosphonyl)but-2-ene with (p-substituted) benzaldehydes gave (1E,3E,5E)-1,3,4,6-tetraarylhexa-1,3,5-trienes in moderate to good yields. Substitution of electron-withdrawing or -donating groups at the para position of the 1,6-diphenyl groups induced a slight bathochromic shift of UV spectra measured in CHCl(3) compared with that of the parent 1,3,4,6-tetraphenylhexa-1,3,5-triene. Although fluorescence was not observed with all the trienes in CHCl(3), they markedly emitted visible light in powder forms with quantum yields of 0.15-0.44. Introduction of amino groups at the para position of the 3,4-diphenyl groups induced a bathochromic shift of emission maxima with good solid-state quantum yields. Thus, the tetraarylated triene framework is found to serve as a new class of fluorophores that exhibit aggregation-induced emission.
authors.affiliation: Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyoto University Katsura, Nishikyo-ku, Kyoto 615-8510, Japan. m.shimizu@hs2.ecs.kyoto-u.ac.jp
authors.forename: Masaki
authors.initials: M
authors.lastname: Shimizu
authors.forename: Hironori
authors.initials: H
authors.lastname: Tatsumi
authors.forename: Kenji
authors.initials: K
authors.lastname: Mochida
authors.forename: Katsuhiro
authors.initials: K
authors.lastname: Shimono
authors.forename: Tamejiro
authors.initials: T
authors.lastname: Hiyama