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本文研究了碱土金属离子-锶、钡及钙可以形成在NMR标尺上是稳定配合物的条件。找到了最适合得到这样的配合物的配体-C222穴醚。研究并归属了碱土金属离子以及碱金属-钠、钾及锂配合物在氯仿中的~(13)C NMR谱。检测出了可用于分析自由配体及其与碱土金属配合物的~(13)C NMR信号,还研究了不同比例混合物的碱土金属及碱金属在氯仿中的~(13)C NMR谱,得到了当自由配体过量时在钡、钙及锶每种金属浓度为1×10~(-3)M的谱中可观测到相当于自由配体及每种离子配合的配体的分立信号。这些信号的积分值的精度可以定量地表征金属离子的浓度,所得结果为首次观测到的。它可以作为用~(13)C NMR波谱建立新的无机分析方法。文中并阐明了作溶液中碱土金属混合物NMR测定方法的具体条件,并讨论了将这一方法扩展到包括一系列碱金属在内的更复杂的混合物的可能性。试验在VARIAN XL-200波谱仪上进行。
This paper studies the conditions that alkaline earth metal ions - strontium, barium and calcium can form stable complexes on the NMR scale. The best ligand for this complex, C222 Cryptand, was found. The ~ (13) C NMR spectra of alkaline earth metal ions and alkali metal - sodium, potassium and lithium complexes in chloroform were studied and assigned. ~ (13) C NMR spectra of the free ligands and their complexes with alkaline earth metals were detected. The ~ (13) C NMR spectra of alkaline earth metals and alkali metals in chloroform with different ratios of mixtures were also studied. When a free ligand is excess, discrete signals corresponding to free ligands and ligands for each ion binding can be observed in the spectrum of 1 x 10 ~ (-3) M for each metal of barium, calcium and strontium. The accuracy of the integrated value of these signals can quantitatively characterize the metal ion concentration and the result is first observed. It can be used as ~ (13) C NMR spectroscopy to establish a new inorganic analytical method. In this paper, the specific conditions for NMR determination of alkaline earth metal mixtures in solution are elucidated and the possibility of extending this approach to more complex mixtures including a range of alkali metals is discussed. The experiment was performed on a VARIAN XL-200 spectrometer.