title: Color-Tunable Solid-State Fluorescence Emission from Carbazole-Based BODIPYs.
abstract: Several carbazole-based boron dipyrromethene (BODIPY) dyes were synthesized by organometallic approaches. Thiazole, benzothiazole, imidazole, benzimidazole, triazole, and indolone substituents were introduced at the 1-position of the carbazole moiety, and boron complexation of each dipyrrin generated the corresponding compounds 1, 2 a, and 3-6. The properties of these products were investigated by UV/Vis and fluorescence spectroscopy, cyclic voltammetry, X-ray crystallography, and DFT calculations. These compounds exhibited large Stokes shifts, and compounds 1, 2 a, and 3-5 fluoresced both in solution and in the solid state. Complex 2 a showed the highest fluorescence quantum yield (ΦF ) in the solid state, therefore boron complexes of the carbazole-benzothiazole hybrids 2 b-f, which had several different substituents, were prepared and the effects of the substituents on the photophysical properties of the compounds were examined. The fluorescence properties showed good correlation with the results of crystal-packing analyses, and the dyes exhibited color-tunable solid-state fluorescence.
authors.affiliation: Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Okayama, 700-8530, Japan. cmaeda@okayama-u.ac.jp.
authors.forename: Chihiro
authors.initials: C
authors.lastname: Maeda
authors.affiliation: Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Okayama, 700-8530, Japan.
authors.forename: Takumi
authors.initials: T
authors.lastname: Todaka
authors.affiliation: Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Okayama, 700-8530, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Ueda
authors.affiliation: Division of Applied Chemistry, Graduate School of Natural Science and Technology, Okayama University, Tsushima, Okayama, 700-8530, Japan. ema@cc.okayama-u.ac.jp.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Ema
keywords: boron dipyrromethene (BODIPY); carbazoles; dyes/pigments; fluorescence; solid-state emission