A series of N,N,N-trialkyl-2-(hydroxyimino)-2-(pyridin-2-yl)ethan-1-aminium nitrates 3a-3h and N,N,N-trialkyl-4-(hydroxyimino)-4-(pyridin-2-yl)butan-1-aminium nitrates 3i-3l representing cationic surfactants with a powerful 1-(hydroxyimino)-1-(pyridin-2-yl)alkyl chelating subunit were prepared as potential selective metal ion extractants. Their extraction ability was tested in transport of Cu2+, Ni2+, Co2+, and Pd2+ through a bulk liquid membrane. The introduction of the cationic group into the extractant molecule increases the selectivity and facilitates the metal ion transport as shown by comparing the transports carried out with ligand surfactants 3 and lipophilic alkyl pyridin-2-yl ketoximes 2. The efficiency and selectivity of the metal ion transport mediated by ligand surfactants 3 depends predominantly on their structure and lipophilicity, i.e. on the number and length of hydrophobic alkyl chains and on the length of the spacer connecting the chelating moiety with the cationic head group of the surfactant.
一系列N,N,N-三烷基-2-(羟基亚胺基)-2-(吡啶-2-基)乙基-1-胺盐3a-3h和N,N,N-三烷基-4-(羟基亚胺基)-4-(吡啶-2-基)丁基-1-胺盐3i-3l代表具有强大1-(羟基亚胺基)-1-(吡啶-2-基)烷基螯合亚基的阳离子表面活性剂,作为潜在的选择性金属离子萃取剂进行制备。它们的萃取能力在通过大量液膜传输Cu2+、Ni2+、Co2+和Pd2+时进行了测试。将阳离子基团引入萃取剂分子中增加了选择性,并促进了金属离子的传输,通过比较使用配体表面活性剂3和亲脂性烷基吡啶-2-基酮肟2进行的传输可以看出。由配体表面活性剂3介导的金属离子传输的效率和选择性主要取决于它们的结构和亲脂性,即疏水烷基链的数量和长度,以及连接螯合基团与表面活性剂阳离子头基的间隔长度。