一种对Fe^2+和Fe^3+识别的显色试剂合成与应用研究

Synthesis and application study of a chromogenic reagent for the recognition of Fe^2+and Fe^3+

以罗丹明6G、水合肼及邻香兰素为原料设计合成了一种新型光学探针(P1),其结构经^1H-NMR,^13C-NMR,MS及元素分析进行表征。通过紫外-可见光谱法研究了探针对金属离子的识别能力。结果表明,探针P1在甲醇/Tris-HCl缓冲(V/V=3∶7,pH 8.34)溶液中无色,随着Fe^2+或Fe^3+的加入,溶液由无色转变为红色,其最大吸收波长为526 nm。最佳测量条件下,在1×10^-6~1×10^-5mol·L^-1范围内,Fe^2+或Fe^3+的浓度与吸光度线性关系良好(Fe^2+,R^2=0.950;Fe^3+,R^2=0.992)。探针与Fe^2+或Fe^3+形成1∶1型配合物,络合常数分别为K(Fe)^2+=1.834×10^5 M^-1、K(Fe)^3+=1.457×10^5 M^-1,识别过程均不可逆。除了高浓度Cu^2+对探针识别Fe^2+或Fe^3+有影响外,其它常见金属离子没有干扰。P1有望发展成为裸眼识别Fe^2+和Fe^3+的高选择性探针。

A novel optical probe(P1)was synthesized by using rhodamine 6G,hydrazine hydrate and o-vanillin as raw materials,and its structure was characterized by 1H-NMR,13 C-NMR,MS techniques and elemental analysis.The recognition properties of the target compound P1 with metal ions had been investigated by UV-Vis spectrophotometry.The results showed that in methanol/Tris-HCl buffer(V/V=3∶7,pH 8.34)solution,the color of P1 changed distinctly from colorless to red in the presence of Fe^2+or Fe^3+,in which the absorption maximum was observed at 526nm.Under the optimal conditions,there was good linear relationship between the concentration of Fe^2+or Fe^3+and the absorbance of probe in the range of 1×10^-6~1×10^-5 mol·L-1(Fe^2+,R^2=0.950;Fe^3+,R^2=0.992).The stoichiometry of the probe P1 with the Fe^2+or Fe^3+was 1∶1,complexation constant were 1.834×10^5M^-1 and 1.457×10^5M^-1,respectively.The recognition process was irreversible.In interference experiments,it was found that common metal ions had almost no interference except for high concentration Cu^2+.Therefore,P1 was expected to develop into a highly selective and naked recognition probe for Fe^2+and Fe^3+.