Ca2+,Th4+和抗磁稀土离子与2,3-二羟基-对-二甲苯胺四乙酸的成络作用

本文用¹H NMR和UV VIS光谱技术研究了DPTA与Ca⁺²、Th⁴⁺和抗磁稀土离子Ia³⁺、Lu³⁺、Y³⁺、Sc³⁺的成络作用,发现配体与抗磁稀土离子为慢交换体系,而与Ca²⁺为快交换体系。确定了络合物的组成,Th⁴⁺与试剂生成1:2络合物,Ca²⁺、La³⁺、Lu³⁺、Y³⁺、Sc³⁺主要生成1:1络合物。络合物组成与溶液pH有关。

COMPLEXATION OF Ca2+,Th4+ AND DIAMAGNETIC RARE EARTH IONS WITH 2,3-DIHYDROXY-p-XYLENEDIIMINOTETRAACETIC ACID

The complexation of 2,3-dihydroxy-p-xylenediiminotetraacetic acid (DPTA) with Ca²⁺,Th⁴⁺ and diamagnetic rare earth ions La³⁺, Lu³⁺, Y³⁺ and Sc³⁺ has been investigated by ¹H NMR and UV VIS absorption spectroscopy methods in this work. Based on the NMR results it is concluded that the reaction of DPTA with the diamagnetic RE ions is a slow exchange reaction, while that with Ca²⁺ is a fast one. The compositions of the complexes are as follows: Th⁴⁺ with DPTA forms 1:2 complex and the other ions Ca²⁺, La³⁺, Lu³⁺, Y³⁺ and Sc³⁺ mainly form 1:1 complexes. The compositions of the complexes are dependent on the pH of the solution. The chemical shift variatfons (△δ) on NMR spectra of dismagnetic RE complexes with DPTA have been compared with λ_max variations (△λ) of UV absorption spectra. A similar order in change was found for both △δ and △λ: Sc³⁺3+≈Lu³⁺ <3+.