一种新的稀土配合物结构分析方法-无顺磁位移混合三稀土法

提出无顺磁位移混合三稀土配合物结构分析方法, 并以丙氨酸稀土为例, 选取Eu-Yb-Pr和Er-Yb-Pr体系从实验上予以验证。研究发现, 通过选择适当的三种顺磁性稀土离子以一定比例混合, 可以抵消顺磁诱导位移, 仅保留顺磁弛豫增强效应, 因而可直观地从谱线半高宽(W1/2)看出稀土配合位点, 从纵向弛豫时间(T1)或谱线半高宽计算稀土与配体磁核间的相对距离。

A novel structure analysis method for lanthanide complex none paramagnetic shift tri-lanthanide mixture method

A new structure analysis method for lanthanide complexes was proposed, that is, none paramagnetic shift tri-lanthanide mixture method. It was found that the paramagnetic induced shift coul be cancelled by mixing three kinds of paramagnetic lanthanide ions in appropriate proportion. As a result, the chelating sites would be seen simplely from the half widths and the relative distances between lanthanide ion and the ligand nucleus could be calculated from the relaxation time (T1) or the half width. Care should be addressed that the analysis method is suitable for the systems in which intramolecular arrangements and intermolecular ligand exchanges are relatively fast on NMR time scale used.