Tb^3+/Ce^3+和NTA配合物在水溶液中的结构分析

Structural analysis of Tb^3+/Ce^3+ and NTA complexes in aqueous solution

通过研究在水溶液中,稀土铽/铈(Tb^3+/Ce^3+)与氨基三乙酸(NTA)形成配合物的条件,来验证溶液分析配合物方法的可行性,分析了2种体系中配合物的具体结构,以及将NTA加入稀土溶液中,对稀土溶液的导电性和荧光性产生的影响,探究其产生影响的机理.实验以水为溶剂,通过荧光分析法和电导分析法对溶液进行测定,结合分子轨道理论、杂化轨道理论、配合物成键原理及荧光猝灭现象等理论进一步分析.NTA的加入会导致Tb^3+溶液电导率和荧光强度的增大,而对Ce^3+的荧光强度产生猝灭作用;Tb^3+和Ce^3+与NTA均以1∶2的配位比例形成九配位结构的配合物.证实了在溶液中该方法分析配合物的可行性和准确性,且与传统的培养单晶的结构分析法相比,具有操作简便、误差小以及干扰因素少等优点.

The complex conditions of Tb^3+/Ce^3+ and nitrilotriacetic acid(NTA) were studied in aqueous solution, and the feasibility of the complex analysis method in solution was verified. The effects of NTA on the conductivity and fluorescence of rare-earth solutions were investigated. In the experiment, water was used as the solvent to measure the fluorescence intensity and conductivity of the solution through fluorescence and conductance analyses. According to the variation trend of the curve and the characteristic emission peak, the structure and properties of the solution were analyzed. In addition, it is further analyzed combining with several methods, such as the molecular orbital theory, principle of complexes, fluorescence quenching, hybrid orbital theory and the other theories. When NTA was added into the system, which will increase the conductivity and fluorescence intensity of Tb^3+ solution, and produce quenching effect on the fluorescence intensity of Ce^3+ solution, nine coordination structure complex was formed when the molar ratio of both Tb^3+/Ce^3+ and NTA was 1∶2. The feasibility and accuracy of the complex analysis in the solution were verified by the experimental study. Compared with the traditional structural analysis method for culturing single crystal, the method has the advantages of simple operation, small error and few interference factors.