The Synerqistic Solvent Extraction of Manganese by Macrocyclic Crown Ethers in Combination with Didodecylnaphthalene Sulfonic Acid: Effect of Macrocycle Substituents

Abstract
Crown ethers in combination with organophilic cation exchangers synergize the extraction of certain metai ions from aqueous solutions, and their selectivity has been thought largely dependent on the correspondence between the crown other's cavity diameter and the metal ion diameter. This work focuses on two crown ethers, tert. -butylbenzo -15-crown-5 (tBB15C5). and tert, -butylcyclohexano 15-crown-5 (tBC15C5) each of which has a cavity diameter of 1.7 to 2.2 × 10−10 m. and their extraction of Mn2+ (ionic diameter 1.4 to 2.2 × 10−10 m) from aqueous nitrate solutions. The organophilic cation exchanger used was didodecylnaphthalene sulfonic acid (HDDNS). The data show no observable complexes of the manganese salt of HDDNS