金属螯合物形成反应的研究受到很大的重视。而氨羧络合剂对相同电荷但半径不一的相似离子的特殊选择性已成为用离子交换法分离该类离子的基础。 最近,我们报道了属于EDTA类的新螯合剂的多组镧系元素的螯合物形成常数。注意到了N、N′间骨架结构的改变,双胺四乙酸对这些离子的螯合能力有明显不同。例如,Gd~(3+)-EEDTA(bis(2-aminoethyl)ether-N,N,N′,N′-tetraacetate,双(2-胺基乙基)醚-N,N, Research on the formation of metal chelates has drawn great attention. However, the special selectivity of ammonia-carboxy complexing agents for similar ions with the same charge but different radii have become the basis for the ion-exchange separation of these ions. Recently, we reported the formation of chelates of multiple groups of lanthanides belonging to the new class of chelates of EDTA. Noted N, N ’skeleton structure changes, diamine tetraacetic acid on the chelation ability of these ions are significantly different. For example, Gd 3+ EEDTA bis (2-aminoethyl) ether-N, N, N ’, N’-tetraacetate,