Acetylene bridged D-(π-A)2 type dyes containing benzophenone moieties: Photophysical properties, and the potential application as photoinitiators
Acetylene bridged D-(π-A)2 type dyes containing benzophenone moieties: Photophysical properties, and the potential application as photoinitiators
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DOI：
10.1016/j.dyepig.2020.108583
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发表时间：
2021
影响因子：
4.5
通讯作者：
Xiaoqin Jia;Di Zhao;Jian You;Tingting Hao;X. Li;J. Nie;Tao Wang
中科院分区：
文献类型：
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作者：
Xiaoqin Jia;Di Zhao;Jian You;Tingting Hao;X. Li;J. Nie;Tao Wang
以咔唑/吩噻嗪/三苯胺为给电子基，通过Sonogashira偶联反应，设计并合成了二苯甲酮乙炔桥联受体-π-桥联-供体-π-桥联受体(A-π-D-π-A)染料。研究了其光物理特性、光化学特性以及双光子吸收特性。所有染料在激发下都表现出良好的分子内/分子间电荷转移特性，并且在720~860 nm波长范围内具有较大的双光子吸收截面。不同电子供体基团的荧光和光化学性质有显著差异。刚性咔唑有利于二苯甲酮类局域激发态和分子内电荷转移激发态的杂化，导致荧光量子产率的异常变化，光稳定性差，作为诺里什Ⅱ引发剂和碘盐敏化剂都具有很好的引发能力。但是，蝶形吩噻嗪和螺旋型三苯胺促进了分子内电荷转移激发态，导致典型的正溶剂变色效应，良好的光稳定性，缺乏作为诺里什Ⅱ引发剂的引发能力。
Acetylene bridged acceptor-π-bridge-donor-π-bridge-acceptor (A-π-D-π-A) dyes (DBPs) based on benzophenone were designed and synthesized via Sonogashira coupling reaction utilizing carbazole/phenothiazine/triphenylamine as electron donating groups. The photophysical properties, photochemistry characteristics, as well as the two-photon absorption properties were studied. All dyes exhibited excellent intra-/intermolecular charge transfer properties upon excitation, and large two photon absorption cross sections in the wavelength range of 720~860 nm. Significant differences in fluorescence and photochemistry properties were found depending on the electron donating groups. The rigid carbazole favored hybridization of benzophenone like local excited state and intramolecular charge transfer excited state, which resulted in abnormal changes in fluorescence quantum yield, poor photostability, and good initiating ability both as Norrish Ⅱ initiator and as sensitizer for iodonium salt. However, the butterfly-shaped phenothiazine and propeller-shaped triphenylamine facilitated intramolecular charge transfer excited states, which resulted in typical positive solvatochromism effect, good photostabilities, and lacking of initiating ability as Norrish Ⅱ initiator.