SYNTHESIS OF BISTHIACROWN ETHERS AND THEIR LIQUID-LIQUID-EXTRACTION OF COPPER(I)

Five new bisthiacrown ethers bearing 7-aza-1,4,10,13-tetrathiacyclohex adecane were succesfully synthesized. A study of the extraction equili bria for copper(I) in the presence of picrate shows that copper(l) is extracted in the form of a 1:1 ion-pair [ML](+)pic(-) complex. The ext raction constants, log K-ex, for copper(I) with these thiacrawn ethers are in the range 6.46-8.05. The extractabilities of the thiacrown eth ers with respect to class a, b and ab metals were examined. Class b me tals except cadmium(II) could be well extracted. The relationship betw een the structure of bisthiacrown ethers and their complexing ability is discussed in detail.