Extraction of scandium and other rare earth elements with a tricarboxylic acid derivative of tripodal pseudcalix[3]arene prepared from a new phenolic tripodal framework

Abstract

We prepared a phenolic tripodal type extraction reagent to investigate the extraction of a series of rare earth metal ions. The extraction reaction and equilibrium extraction constants for rare earth ions with the tripodal extractant were evaluated using slope analysis and Job’s method. The tripodal reagent exhibited remarkably high extraction ability compared with a corresponding monopodal compound, and exhibited different extraction selectivities for rare earth metal ions than a calix[4]arene derivative because of the different size of the coordination site. The developed phenolic tripodal extraction reagent provides a new framework with a different size coordination site to those in calix[4]arene and alkyltrimethylol type tripodal compounds.