Regulation of excitation transit ons by molecular design endowing full-color-tunable emissions with unexpected high quantum yields for bioimaging application  

作　　者：Feng Liu Shengliang Li Ruihong Duan Shuhai Qiu Yuanping Yi Shu Wang Xiaozhang Zhu 

机构地区：[1]Beijing National Laboratory for Molecular Sciences,CAS Key Laboratory of Organic Solids,Institute of Chemistry,Chinese Academy of Sciences,Beijing 100190,China [2]University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Science China Chemistry》2018年第4期418-426,共9页中国科学（化学英文版）

基　　金：supported by the National Basic Research Program of China(2014CB643502);the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB12010200);the National Natural Science Foundation of China(91333113,21572234)

摘　　要：Organic fluorophores are indispensible in chemical/biological imaging. The conjugated fluorescent molecules simultaneously possessing highly tunable emission, high quantum yield in solvents of different polarities, and large Stokes shift are quite rare. Herein, we report a new category of fluorophores based on diarylated thieno[3,4-b]thiophenes efficiently synthesized by direct C-H arylation reaction. TbT-Fluors showed full-color-tunable emissions with large Stokes shifts. Intriguingly,the fluorescence quantum yields of TbT-Fluors are barely sensitive to solvent polarities, approaching 100%. Based on photophysical and theoretical investigations, we found that the enhanced oscillator strength of the S_1-S_0 transition and increased T2-S1 energy difference can sufficiently compensate the negative effect from the decreased energy gap and increased reorganization energy in dimethyl sulfoxide(DMSO). Bioimaging applications revealed that some TbT-Fluors can penetrate the cell membrane and are superior for imaging in terms of high photochemical stability and low cytotoxicity. Furthermore, TbT-PhF exhibits specific colocalization with mitochondria in living cells.Organic fluorophores are indispensible in chemical/biological imaging. The conjugated fluorescent molecules simultaneously possessing highly tunable emission, high quantum yield in solvents of different polarities, and large Stokes shift are quite rare. Herein, we report a new category of fluorophores based on diarylated thieno[3,4-b]thiophenes efficiently synthesized by direct C-H arylation reaction. TbT-Fluors showed full-color-tunable emissions with large Stokes shifts. Intriguingly,the fluorescence quantum yields of TbT-Fluors are barely sensitive to solvent polarities, approaching 100%. Based on photophysical and theoretical investigations, we found that the enhanced oscillator strength of the S_1-S_0 transition and increased T2-S1 energy difference can sufficiently compensate the negative effect from the decreased energy gap and increased reorganization energy in dimethyl sulfoxide（DMSO）. Bioimaging applications revealed that some TbT-Fluors can penetrate the cell membrane and are superior for imaging in terms of high photochemical stability and low cytotoxicity. Furthermore, TbT-PhF exhibits specific colocalization with mitochondria in living cells.

关 键 词：donor-aeceptors systems DYES thieno[3 4-b]thiophene fluorescence BIOIMAGING 

分 类 号：TQ617.3[化学工程—精细化工]