A series of new ligands bearing three diglycolamide functions preorganized at the C-pivot and trialkylphenyl platforms was synthesized. They are very efficient extractants for Am3+ and Eu3+ with an up to five times relative extraction ability for Eu3+. The distribution coefficients are up to 1000 times increased upon alkylation or arylation of the N-position of the diglycolamide moieties. The tripodal diglycolamides show a 1 : 1 metal to ligand stoichiometry as proven with three independent methods for the complexation of the 3-pentyl N-substituted diglycolamide ligand with Eu3+ (K = 2.5 × 105 M−1 in acetonitrile–water). A cage-like cryptand, containing three diglycolamide units, was prepared using a Eu3+ templated synthesis. However, it does not exhibit improved extraction properties.
合成了一系列新型
配体,这些
配体在C轴和三烷基苯平台上预先排列了三个
二甘醇酰胺功能单元。它们对Am3+和Eu3+具有非常高效的萃取能力,对Eu3+的相对萃取能力可提高至五倍。通过
二甘醇酰胺部分的N位烷基化或芳基化,分配系数可提高一千倍。三脚架型的
二甘醇酰胺显示了1:1的
金属与
配体化学计量关系,通过三种独立的方法证实了3-戊基N-取代
二甘醇酰胺
配体与Eu3+的络合(在
乙腈-
水中,K = 2.5 × 105 M−1)。利用Eu3+模板合成法,制备了一种类似笼状的隐肽,内含三个
二甘醇酰胺单元。然而,它并未展现出更优的萃取性能。