Chowdhury Aniket, Mukherjee Partha Sarathi
Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bangalore 560 012, India.
J Org Chem. 2015 Apr 17;80(8):4064-75. doi: 10.1021/acs.joc.5b00348. Epub 2015 Apr 9.
This paper demonstrates the role of solvent in selectivity and sensitivity of a series of electron-rich compounds for the detection of trace amounts of picric acid. Two new electron-rich fluorescent esters (6, 7) containing a triphenylamine backbone as well as their analogous carboxylic acids (8, 9) have been synthesized and characterized. Fluorescent triphenylamine coupled with an ethynyl moiety constitutes π-electron-rich selective and sensitive probes for electron-deficient picric acid (PA). In solution, the high sensitivity of all the sensors toward PA can be attributed to a combined effect of the ground-state charge-transfer complex formation and resonance energy transfer between the sensor and analyte. The acids 8 and 9 also showed enhanced sensitivity for nitroaromatics in the solid state, and their enhanced sensitivity could be attributed to exciton migration due to close proximity of the neighboring acid molecules, as evident from the X-ray diffraction study. The compounds were found to be quite sensitive for the detection of trace amount of nitroaromatics in solution, solid, and contact mode.
本文展示了溶剂在一系列富电子化合物检测痕量苦味酸时的选择性和灵敏度方面所起的作用。合成并表征了两种含有三苯胺骨架的新型富电子荧光酯（6, 7）及其类似的羧酸（8, 9）。与乙炔基部分相连的荧光三苯胺构成了对缺电子苦味酸（PA）具有富π电子选择性和灵敏性的探针。在溶液中，所有传感器对PA的高灵敏度可归因于基态电荷转移复合物形成以及传感器与分析物之间共振能量转移的综合效应。酸8和9在固态下对硝基芳烃也表现出增强的灵敏度，并且它们增强的灵敏度可归因于相邻酸分子紧密接近导致的激子迁移，这从X射线衍射研究中可以明显看出。发现这些化合物在溶液、固态和接触模式下对检测痕量硝基芳烃非常灵敏。
