摘要/Abstract

对一种新合成的化合物5-苯基-2-（3-三氟甲苯）-2H-1，2，3-三氮唑-4-羧酸乙酯（EPFC），利用GaussView5.0量化程序及含时密度泛函TD-DFT方法对其结构性质及理论光谱进行了计算；并将其与罗丹明B反应合成了一种新型含有1，2，3-三氮唑基团的化合物REPFC，通过核磁共振及高分辨质谱对其进行了结构表征；应用紫外吸收和荧光分析法研究了REPFC与15种金属离子的作用.结果表明：EPFC易失去电子，计算光谱与实验光谱的结果较好地吻合；在一定浓度范围内，肉眼可观察到REPFC仅对Hg²⁺有粉红色的显色反应，使其荧光增强，并且反应时间很快，不受其他金属离子的影响，反应络合比为1：2，提出了REPFC与Hg²⁺显色反应的off-on机理模型，研究结果可为进一步开发此类三氮唑化合物在生理条件下的应用提供理论指导.
关键词: 5-苯基-2-(3-三氟甲苯)-2H-1,2,3-三氮唑-4-羧酸乙酯, 罗丹明B, 合成, 显色反应, Hg²⁺离子
Ethyl 5-phenyl-2-(3-(trifluoromethyl)phenyl)-2H-1,2,3-triazole-4-carboxylate (EPFC), a newly synthesized compound, is used to study its structural properties and explore as a fluorescent probe for metal ions. EPFC was investigated in terms of structural, fluorescence spectroscopic, UV-Vis spectroscopic and theoretical analysis by using HF/6-31G(d), CIS/6-31G(d) and B3LYP/6-31G(d) methods, respectively. The corresponding product was characterized by NMR and HRESIMS methods. The interactions of the compound with 15 kinds of metal ions (Pb²⁺, Mn²⁺, K⁺, Na⁺, Ag⁺, Ca²⁺, Cd²⁺, Co²⁺, Cu²⁺, Fe³⁺, Zn²⁺, Ni²⁺, Hg²⁺, Li⁺ and Mg²⁺) were investigated by UV absorption spectroscopy and fluorescence spectroscopy. The quantum chemical values suggested that it is easy for EPFC to lose electron with weak electron accepting ability by frontier molecular orbital analysis. The calculated spectra were complimented with experimental measurements in great degree. In addition, a novel rhodamine B derivative containing 1,2,3-triazole unit, and REPFC was successfully designed and synthesized by the reaction between rhodamine B and EPFC. REPFC displayed more selectivity response to Hg²⁺ ion than other metal ions in N,N-dimethylformamide (DMF)-H₂O (V/V=1/1, pH 7.4) within a REPFC concentration range of 2.67×10^-5~4.67×10^-5 mol·L^-1 with an fluorescent enhancement and a rapid chemical reaction. The triazole appended colorless chemosensor turns to pink upon complex formation only with Hg²⁺ions even in the presence of other common metal ions and enables naked-eye detection. The coordination mechanism and turn on/off fluorescence for Hg²⁺ ions were well proposed by explaining Hg²⁺ inducing the ring-opened rhodamine B moiety. This study was an advancement for the application of 1,2,3-triazole compound and provides guidance for using simple and high-selectivity Hg²⁺ probes in aqueous solutions under physiological conditions.
Key words: 5-phenyl-2-(3-(trifluoromethyl) phenyl)-2H-1,2,3-triazole-4-carboxylate, structural property, rhodamine B, synthesis, chromogenic reaction, Hg²⁺ ion


PDF全文下载地址:

点我下载PDF