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合成了九个不同辛基结构的辛基膦酸单辛酯,测定了它们的正十二烷溶液在恒定离子强度和不同酸度的硝酸介质中萃取镧、铕和铅的分配比,并以外推法得到了归一化的分配比数值,从而进行了萃取剂结构与性能关系的研究。考察了辛基膦酸单辛酯的烷基支链化程度时萃取镧系元素的能力和分离性能的影响:随着邻近配位基团的烷基支链化程度的增加,其萃取能力下降;但一定的支链对萃取剂分子是必需的,如2-乙基已基膦酸单2-乙基己基酯和正辛基膦酸单1-甲基庚基酯皆具有最佳的分离性能。从空间效应解释了所得的结果。
Nine octyl octyl phosphonates with different octyl structures were synthesized and the distribution ratios of lanthanum, europium and lead extracted from their n-dodecane solution in nitric acid solution with constant ionic strength and different acidity were measured and extrapolated Method to get the normalized distribution ratio values, and thus the relationship between extraction agent structure and performance of the study. The influence of the degree of alkyl branching of octylphosphonic acid mono-octyl ester on the ability of extraction of lanthanides and the separation performance was investigated: the ability of extraction decreased as the degree of alkyl branching of adjacent coordination groups increased ; But certain branching is necessary for the extractant molecules, such as 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester and n-octylphosphonic acid mono-1-methylheptyl ester have the best separation performance . The results obtained are explained from the spatial effect.