title: Highly emissive organic solids containing 2,5-diboryl-1,4-phenylene unit.
abstract: We disclosed a series of pi-conjugated systems containing 2,5-bis(dimesitylboryl)-1,4-phenylene as the core unit and electron-donating amino groups at the terminal positions. The extension of the ppi-pi* conjugation in the diborylphenylene moiety along the short axis of the pi-conjugated framework as well as the incorporation of two bulky dimesitylboryl groups at the para-positions makes this moiety act as a unique bulky pi-electron-accepting unit. As a consequence, these systems behave like donor-acceptor-donor quadrupolar pi-electron systems and show a large solvatochromism in the fluorescence spectra. Moreover, these organoboron pi systems exhibit intense fluorescence even in the solid state with the quantum yields of 0.73-0.90.
authors.affiliation: Department of Chemistry, Graduate School of Science, Nagoya University, and SORST, Japan Science and Technology Agency, Chikusa, Nagoya 464-8602, Japan.
authors.forename: Cui-Hua
authors.initials: CH
authors.lastname: Zhao
authors.forename: Atsushi
authors.initials: A
authors.lastname: Wakamiya
authors.forename: Yuko
authors.initials: Y
authors.lastname: Inukai
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Yamaguchi