Mg和Ca-PDTA金属络合物分子内过程的DNMR谱

~1H NMR不但可以研究有机化学、金属有机化合物的立体结构,而且在某些适当的金属络合物体系中,还可以研究金属离子和配体间的迁移性及分子内过程的动力学。对于EDTA类金属络合物的DNMR研究表明分子内过程包括三种形式,即Δ≒Λ构型转化,N原子反转以及所谓的B≒R转化。本文作者为进一步探讨分子内过程,选PDTA为配体进行了DNMR研究,取得一些有意义的新结果。实验部分

THE DNMR SPECTRA OF INTRAMOLECULAR PROCESS IN Mg- AND Ca-1,2-PDTA COMPLEXES

The DNMR Spectra of the intramolecular processes occurring in Mg-, Ca-, Sr-and Ba-1,2-propylenediamine-tetraacetic acids(1,2-PDTA) are reported in this paper. The relative activation parameters have been obtained by performing computer line shape analysis. The experimental results show that the rates of the lone pair inversion of the two nitrogen atoms in these complexes are different, but their activation energies are similar. The nitrogen inversion process of these complexes belongs to twist mechanism through a trigonal prismatic intermediate.