Key Laboratory of Chemistry of Northwestern Plant Resources and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, PR China.
Spectrochim Acta A Mol Biomol Spectrosc. 2011 Feb;78(2):726-31. doi: 10.1016/j.saa.2010.12.004. Epub 2010 Dec 9.
A series of nitro-substituted 3,3'-bis-indolyl phenylmethane derivatives were synthesized and their anion binding properties were investigated in detail. The introduction of the electron-withdrawing nitro group into indole unit and/or meso-phenyl ring, which leads to the increased acidity of indole NH and meso-position CH proton, has a positive effect on anion binding. The nitro-substituted bis(indolyl)methane receptors exhibited selective colorimetric sensing of F- anion, as revealed by the notable color and spectral changes, rationally due to the deprotonation of the indole NH of the receptor. Meanwhile, the additive introduction of the nitro substituents on the meso-phenyl ring of bis(indolyl)methane can lead to the deprotonation of the meso-position CH and further induce an irreversible oxidation process obtaining bis(indolyl)methene product in the F- anion sensing system.
一系列硝基取代的 3,3'-双吲哚基苯基甲烷衍生物被合成出来，并对其阴离子结合性能进行了详细研究。在吲哚单元和/或间位苯基环上引入吸电子硝基取代基，会增加吲哚 NH 和间位 CH 质子的酸性，这对阴离子结合有积极影响。硝基取代的双（吲哚基）甲烷受体对 F-阴离子表现出选择性比色传感，这是由于受体的吲哚 NH 去质子化所致，这可以通过明显的颜色和光谱变化来揭示。同时，在双（吲哚基）甲烷的间位苯基环上添加硝基取代基可以导致间位 CH 去质子化，并进一步诱导不可逆的氧化过程，从而在 F-阴离子传感体系中获得双（吲哚基）甲烷产物。
