杯芳烃衍生物液－液萃取和液膜传输银的对比研究及机理探讨

以4类含硫、硒、氮等杂原子基团二取代的杯4]芳烃五衍生物（1－14）为中 性载体，在H2O-CHCl3-苦味酸体系萃取银和H2O-CHCl3-H2O液膜体系中传输银进行 了对比研究。萃取和传输结果具有一致性，除了苯并噻唑取代的杯4]芳烃衍生物 （3－6）外，其它10个含硫、硒、氮的杯4]芳烃衍生物1－14均对软重金属银和汞 有很高的选择性，而吡啶取代的杯4]芳烃衍生物7－10对铅有一定的萃取选择性， 其中羟基硫醚取代的杯4]芳烃衍生物11－14对银的萃取率和传输速率最大。并且 就杯4]芳烃衍生物对银的传输机理进行了探讨，发现传输速率随源相中金属离子 浓度和有机相中载体浓度的增加而增大，因此推论这是由金属离子浓度梯度推动下 的传输。

A Comparison Study between Liquid Extraction and Liquid Membrane Transport of Silver by Calix[4] arene Derivatives

A study on the extraction properties from aqueous phase to organic phase and the carrier-mediated transport at 25℃ in H2O-CHCL_3-H2O liquid membrane has been performed by using calix4]arene derivatives (1～14)bearing a wide range of functional groups such as thio (seleno) ether, (benzothiazolyl) thioalkyl, pyridylalkoxy and thioalkyl. The results of liquid-liquid extraction and liquied membrane transport show that the calixarenes have nearly consistent selectivity for silver and mercury ions. All derivatives except calix4]arenes substituted by (benzothiaxolyl) thioalkyl group (3～6) are efficient extractants and neutral carriers with high selectivity for silver. Calix 4]arenes substituted by pyridylalkoxy group (7～10) show high selectivity for lead in liquid-liquid extraction. The complexation studies reveal that the affinity toward Ag~+，Hg2~+, Pb2~+ is influenced by atom types and lipophilic groups at the lower rim of the caliarenes. The highest extraction and the fastest transport rates of silver are obtained by calix4] arene substituted by thioalkoxy group (11～14). The transport rates increase with increasing concentration of the cations in the source phase and of the carrier in the CHCl2 phase. There is evidence that the carrier-mediated silver transport through bulk liquid membrane is a concentration gradient diffusion process.