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[摘要]：Chemodosimeters S1 and S2 having salicylaldehyde and triphenylamine functionalities were synthesized, and the changes in their absorption and emission properties in the presence of anions were evaluated. S1 and S2 act as selective colorimetric and fluorimetric molecular probes for sensing and signalling cyanide. The signal transduction mechanism was investigated by UV/Vis absorption, emission, and NMR spectroscopy, and was supported by DFT calculations. The interaction between the receptors and cyanide ions causes large changes in both colour and emission intensity. A significant enhancement in fluorescence intensity was caused by the better nucleophilicity of the cyanide and by the carbonyl activation by the phenol proton of the salicylaldehyde group in the dosimeter through an intramolecular hydrogen bond. Intramolecular charge transfer from the negatively charged quinonoidal fragment to the triarylamine group was responsible for the colorimetric response. The detection limits were found to be 1.55 and 0.72 mu M for S1 and S2, respectively, with fluorimetric enhancement factors of 350 and 25. |
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