NMR self‐diffusion measurements: A different approach to complexation phenomena
NMR self‐diffusion measurements: A different approach to complexation phenomena
复制标题
核磁共振自扩散测量：复杂现象的不同方法
DOI：
10.1002/mrc.1260271208
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发表时间：
1989
影响因子：
2
通讯作者：
H. Sterk
中科院分区：
文献类型：
--
作者：
M. Geringer;H. Sterk
1H和133 Cs NMR自扩散测量通过脉冲梯度自旋回波法（PGSE）进行，以评估Cs和18-冠-6以及Cs和一些乙二醇在D2 O中的络合物形成常数。计算的络合物形成常数尽可能地通过使用基于弛豫数据的类似计算来检查。化学位移测量不允许在这些系统中的复杂的形成常数的评价。引入交叉检查以验证基于扩散数据的计算。对Na、K、Cs络合物和N-苯基氮杂-15-冠-5在甲醇中进行类似的研究。在这种情况下，扩散数据和弛豫速率和化学位移数据的分析导致1：1复合物的复合物形成常数，这与先前的报告表明形成2：1复合物相反。
1H and 133Cs NMR self‐diffusion measurements were performed by means of the pulsed gradient spin‐echo method (PGSE) to evaluate the complex formation constants of Cs and 18‐crown‐6 and those of Cs and some ethylene glycols in D2O. The calculated complex formation constants were checked as far as possible by using similar calculations based on relaxation data. Chemical shift measurements do not allow the evaluation of complex formation constants in these systems. A cross‐check was introduced to verify the calculations based on the diffusion data. Similar investigations were performed on Na, K, Cs complexes and N‐phenylaza‐15‐crown‐5 in methanol. In this case, analysis of the diffusion data and as the relaxation rate and chemical shift data led to complex formation constants for 1:1 complexes, which is in contrast to a previous report suggesting the formation of 2:1 complexes.