Eu3+离子与α-氨基酸配合物与介质酸度关系的13C NMR研究

摘要

本文对Eu3+离子与α-氨基丙酸及组氨酸配合物体系在不同酸度条件下所表现出的13CNMR波谱进行了研究,发现配合物的13C NMR化学位移值随介质酸度的不同而发生规律性变化,认为这是由于不同的酸度促使配合物的结构形式产生变化所致.对长期有争议的α-氨基参与配位的酸度条件作了讨论,指出α-氨基在微酸性条件下配位的可能性,并通过计算予以进一步证实.%The 13C NMR spectra of Eu(Ⅲ) complexes with alanine and histidine were investigated respectively. An interesting regularity of 13C NMR shifts was revealed. The relationship between the structure of the obtained complexes and pH condition was discussed in detail. It was pointed out that the variations in 13C NMR shifts were resulted from the change of the complex structure. The possibility of coordination through the nitrogen in α - amino group under a weak acidic condition was also discussed. Inaddition, a calculation gave a further support to this view point.