由中央2,1,3-苯并噻二唑(1),噻吩并[3,2- b ]噻吩(2)和苯并[1,2- b:4,5- b ' ]二噻吩(3,4),分别合成了通过简洁Pd-催化的交叉偶联反应。1-3的晶体结构和单二聚二氢吲哚基末端衍生物(5)确定。对其光物理性质的广泛检查和比较表明,中央部分的给电子或受电子特征可以极大地调节其光子吸收和发射性质。在这些准低聚噻吩发色团中,2,1,3-苯并噻二唑衍生物1具有最高的光致发光量子产率(0.70)和最长的荧光寿命(12.89 ns)。特别是,其两光子激发荧光(TPEF)在740–880 nm范围内的激发光谱表明,A–π–D–π–A型化合物的两光子吸收截面最大4是A–π–A–π–A型化合物1的近8倍,这清楚地证明了共轭桥的长度和有效离域电子的数量可能在增强双光子吸收中起重要作用。
The synthesis and single and two-photon excited fluorescence of a new quasi-quadrupolar organoborane compound
摘要:
A new acceptor-It-acceptor quadrupolar compound with a dimesitylboryl as acceptor and 2,7-dithienylfluorene as the conjugated bridge has been synthesized using the Suzuki-Miyaura coupling reaction. Its single and two-photon related photo-physical properties were experimentally examined. The combination of a large two-photon cross-section (delta = 1150 GM at 730 nm in hexane), high emission quantum yield (phi = 0.81 in hexane) and a strong binding constant with fluoride anions (K-1 = 3.0 x 10(5) mol(-1) L) make this compound attractive for application as a two-photon excited fluorescent chemosensor for fluoride anions. (C) 2010 Elsevier B.V. All rights reserved.