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, an...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.展开更多
Temporal oscillations of the bromate-4-aminophenol system have been studied in the presence of four different catalysts： tris（1,10-phenanthroline）iron（Ⅱ） sulfate （ferroin）, Ce（Ⅲ）, Mn（Ⅱ）, and Fe（Ⅱ）. Tr...Temporal oscillations of the bromate-4-aminophenol system have been studied in the presence of four different catalysts： tris（1,10-phenanthroline）iron（Ⅱ） sulfate （ferroin）, Ce（Ⅲ）, Mn（Ⅱ）, and Fe（Ⅱ）. Transient temporal oscillations were observed in the four catalyzed systems when the reactions were conducted in a stirred batch reactor. The induction time was prolonged by the presence of ferroin, but it was shortened in the Ce（Ⅲ）- and Mn（Ⅱ）-catalyzed systems. On the other hand, the number of peaks was significantly decreased in the presence of ferroin. The development of oscillatory behaviour was found to be more sensitive to the ratio of bromate and 4-aminophenol concentration than to their absolute concentrations. The reaction rates of 4-aminophenol with Ce（IV） and 4-aminophenol with ferritin were measured directly by spectroscopic methods in a sulfuric acid medium.展开更多
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)
文摘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.
基金supported by the Natural Science and Engineering Research Council (NSERC),Canada,the National Natural Science Foundation ofChina (21003010)the Doctoral Fund of the Ministry of Education of China (20101101120032)+1 种基金the China Postdoctoral Science Foundation(20100470558)the Excellent Young Scholars Research Fund of Beijing Institute of Technology (2009 Y1017)
文摘Temporal oscillations of the bromate-4-aminophenol system have been studied in the presence of four different catalysts： tris（1,10-phenanthroline）iron（Ⅱ） sulfate （ferroin）, Ce（Ⅲ）, Mn（Ⅱ）, and Fe（Ⅱ）. Transient temporal oscillations were observed in the four catalyzed systems when the reactions were conducted in a stirred batch reactor. The induction time was prolonged by the presence of ferroin, but it was shortened in the Ce（Ⅲ）- and Mn（Ⅱ）-catalyzed systems. On the other hand, the number of peaks was significantly decreased in the presence of ferroin. The development of oscillatory behaviour was found to be more sensitive to the ratio of bromate and 4-aminophenol concentration than to their absolute concentrations. The reaction rates of 4-aminophenol with Ce（IV） and 4-aminophenol with ferritin were measured directly by spectroscopic methods in a sulfuric acid medium.
