College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou 571158, China.
Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, Haikou 571158, China.
Spectrochim Acta A Mol Biomol Spectrosc. 2018 Jul 5;200:127-135. doi: 10.1016/j.saa.2018.04.009. Epub 2018 Apr 11.
5-Methyl-2-phenyl-2H-1,2,3-triazole-4-carboxylic acid (MPTC), a newly synthesized compound, was explored to study the structural properties and theoretical spectra by using GaussView5.0 program package and the time dependent density functional theory (TD DFT). The calculated quantum chemical values suggested that it is easy for MPTC to lose electron with weak electron accepting ability. And the results of experimental measurements on fluorescence and absorption spectra were consistent with that of the calculated spectra in great degree. In addition, MPTC was successfully used and synthesized a novel rhodamine B derivative RMPTC containing 1,2,3-triazole unit. It is found that there is special chromogenic response of RMPTC to Hg ions in N, N-dimethylformamide (DMF)-HO (v/v=1/1, Tris-HCl, pH7.4) with the triazole appended colorless chemosensor turned to pink and enabled naked-eye detection. The fluorescence signal for RMPTC-Hg system was not affected by other coexisting metal ions. The 1:2 stoichiometric structure of RMPTC and Hg is confirmed using a Job's plot estimation and TD DFT calculations. The corresponding "off-on" fluorescence mechanism of RMPTC binding to Hg which were ascribed to Hg inducing the ring-opened rhodamine B moiety were proposed. This study was an advancement for the application of 1,2,3-triazole compound in photophysical chemistry field and provides guidance for exploring simple and high-selectivity Hg probes in aqueous solutions under physiological conditions.
5-甲基-2-苯基-2H-1,2,3-三唑-4-羧酸（MPTC）是一种新合成的化合物，通过使用 GaussView5.0 程序包和时间相关密度泛函理论（TD DFT）对其结构性质和理论光谱进行了研究。计算量子化学值表明，MPTC 很容易失去电子，具有较弱的电子接受能力。荧光和吸收光谱的实验测量结果在很大程度上与计算光谱一致。此外，成功地使用 MPTC 合成了一种新型的罗丹明 B 衍生物 RMPTC，其中含有 1,2,3-三唑单元。研究发现，RMPTC 对 N, N-二甲基甲酰胺（DMF）-HO（v/v=1/1，Tris-HCl，pH7.4）中的 Hg 离子具有特殊的显色响应，无色的三唑 appended 化学传感器变为粉红色，实现了肉眼检测。RMPTC-Hg 体系的荧光信号不受其他共存金属离子的影响。使用 Job's 图估计和 TD DFT 计算证实了 RMPTC 和 Hg 的 1:2 化学计量结构。提出了 RMPTC 与 Hg 结合的“关-开”荧光机制，归因于 Hg 诱导罗丹明 B 部分开环。这项研究推进了 1,2,3-三唑化合物在光物理化学领域的应用，并为在生理条件下探索简单、高选择性的 Hg 探针提供了指导。
