Mixed ligand chelate extraction of lanthanide ions in systems involving 7-(1-vinyl-3,3,6,6-tetramethylhexyl)-8-quinolinol, 8-quinolinol, and 1,10-phenanthroline

Abstract

A study of the equilibrium extraction behavior of a series of representative tervalent lanthanide ions, Pr, Eu, and Yb, was carried out with chloroform solutions containing either 7-dodecenyl-8-quinolinol (DDQ or HK) alone or combined with 1,10-phenanthroline (phen). The results demonstrated that the lanthanides are extracted as a simple chelate, LnK/sub 3/, or in the presence of phen, as LnK/sub 3/.phen. Solvent extraction of lanthanides has been studied further with mixtures of HK and 8-quinolinol (HQ) in chloroform. The mixed complexes in chloroform were considered to be LnK/sub 2/Q, and at higher 8-quinolinol concentration LnKQ/sub 2/, but the addition of 0.1 M phen changes the species to LnK/sub a/Q/sub 3-a/.phen complexes. The formations of mixed complexes and addition of phen improve both the extraction and separation.