一种新型苯并咪唑-酰腙衍生物用于比色和荧光识别F^-和AcO^-

A Novel Benzimidazole-Hydrazone Derivative for Colorimetric and Fluorescent Recognition of F^- and AcO^-

合成出了1个新的苯并咪唑-酰腙衍生物,N'-(2-羟基-1-萘基)亚甲基-2-[2-(4-甲基苯磺酰基甲基)-1H-苯并咪唑-1-基]乙酰肼(L),并利用IR,1H NMR,13C NMR,HRMS和元素分析对其结构进行了表征.利用裸眼、紫外-可见与荧光光谱研究了L对阴离子的识别性能.研究结果表明,向化合物L的CH3CN溶液中加入F^-,AcO^-和H2PO4^-后,溶液由无色变为亮黄色.在紫外灯下(λ=365 nm),加入F^-和AcO^-后,L的溶液发射出黄色荧光.表明化合物L可作为裸眼识别F-,AcO-和H2PO4-的探针.紫外和荧光光谱实验结果显示,探针L可高选择性和高灵敏性识别F-和AcO-.探针L与F-和AcO-的结合常数(Ka)分别为4.25×10^3和2.96×10^4 L·mol^-1,检出限(DL)分别为3.63×10^-7和8.51×10^-8 mol·L^-1.Job曲线和密度泛函理论(DFT)计算证明,探针L与F^-/AcO^-是1∶1配位.通过1H NMR滴定确定了探针L与F^-/AcO^-的络合机理.实验结果表明,化合物L可作为检测F^-和AcO^-的比色和荧光探针.

A novel benzimidazole-hydrazone derivative,N'-(2-hydroxy-1-naphthyl)methylene-2-[2-(4-methylphenylsulfonyl-methyl)-1H-benzoimidazol-1-yl]acetohydrazide(L),was synthesized and characterized by IR,1H NMR,13C NMR,HRMS and elemental analysis.The recognition properties of L for anions were studied by naked eye,ultraviolet-vis and fluorescence spectroscopy.The results showed that the color of the solution changes from colorless to bright yellow upon addition of F^-,AcO^-and H2PO4-to the CH3CN solution of compound L.The solution of L emitted yellow fluorescence after the addition of F^-and AcO^-under the UV lamp(λ=365 nm).It indicated that compound L can be used as a probe for the naked eye to recognize F^-,AcO^-and H2PO4^-.The experimental results of UV and fluorescence spectroscopy showed that the probe L can recognize F-and AcO-with high selectivity and sensitivity.The binding constants(Ka)of probe L to F^-and AcO^-were 4.25×10^3 and 2.96×10^4 L·mol^-1,respectively.The detection limits(DL)were 3.63×10^-7 and 8.51×10^-8 mol·L^-1,respectively.The stoichiometry of complexation between L and F^-/AcO^-was 1:1,which was supported by the Job's plot and density functional theory(DFT)calculations.The mechanism of binding of L with F^-/AcO^-was established by 1H NMR titration.The results showed that compound L can be used as a colorimetric and fluorescent probe for detecting F^-and AcO^-.