Extractability of Copper(II) and Zinc(II) with Crown Ethers as Picrates

Abstract

The extraction of copper(II) and zinc(II) with picrate ion and 12-crown-4(1,4,7,10-tetraoxacyclododecane) or 15-crown-5(1,4,7,10,13-pentaoxacyclopentadecane) into benzene or chloroform has been measured. The extraction of copper(II) is better than that of zinc(II), in spite of the similar ionic size, although the difference is much smaller than that in the extraction of these metal ions with β-diketones.