title: Tuning the solid-state luminescence of BODIPY derivatives with bulky arylsilyl groups: synthesis and spectroscopic properties.
abstract: Boron dipyrromethenes (BODIPYs) with bulky triphenylsilylphenyl(ethynyl) and triphenylsilylphenyl substituents on pyrrole sites were prepared via Hagihara-Sonogashira and Suzuki-Miyaura cross-coupling with ethynyl-terminated tetraphenylsilane and boronic acid-terminated tetraphenylsilane. The chromophores are designed to prevent intermolecular π-π stacking interaction and enhance fluorescence in the solid state. Single crystals of 1 a and 2 b for X-ray structural analysis were obtained, and weak π-π stacking interactions of the neighboring BODIPY molecules were observed. Spectroscopic properties of all of the dyes in various solvents and in films were investigated. Triphenylsilylphenyl-substituted BODIPYs generally show more pronounced increases in solid-state emission than triphenylsilylphenyl(ethynyl)-substituted BODIPYs. Although the simple BODIPYs do not exhibit any fluorescence in the solid state (Φ=0), arylsilyl-substituted BODIPYs exhibit weak to moderate solid-state fluorescence with quantum yields of 0.03, 0.07, 0.10, and 0.25. The structure-property relationships were analyzed on the basis of X-ray crystallography, optical spectroscopy, cyclic voltammetry, and theoretical calculations.
authors.affiliation: Key Laboratory of Organosilicon Chemistry and Material Technology Ministry of Education, Hangzhou Normal University, Hangzhou, 310012, PR China.
authors.forename: Hua
authors.initials: H
authors.lastname: Lu
authors.forename: Qiuhong
authors.initials: Q
authors.lastname: Wang
authors.forename: Lizhi
authors.initials: L
authors.lastname: Gai
authors.forename: Zhifang
authors.initials: Z
authors.lastname: Li
authors.forename: Yuan
authors.initials: Y
authors.lastname: Deng
authors.forename: Xuqiong
authors.initials: X
authors.lastname: Xiao
authors.forename: Guoqiao
authors.initials: G
authors.lastname: Lai
authors.forename: Zhen
authors.initials: Z
authors.lastname: Shen