Liquid-Liquid Extraction of Transition Metal Cations by Glyoximes and Their Macrocyclic Glyoxime Ether Derivatives

Liquid-liquid extraction of various alkalis (Li+, Na+, K+, and Cs+), transition metals (Co2+, Ni2+, Cu2+, Zn2+, Cd2+, and Hg2+), and Pb2+ cations with phenylglyoxime (L1), p-tolylglyoxime (L2), N′-(4′-Benzo[15-crown-5])phenylaminoglyoxime (L3), and N′-(4′-Benzo[15-crown-5])-p-tolylaminoglyoxime (L4) from the aqueous phase into the organic phase was carried out. For comparison, the corresponding two glyoximes and their macrocyclic glyoxime ether derivatives were also examined. Crown ether groups having ligands (L3, L4) carry especially Na+ cation from aqueous phase to organic phase. The extraction equilibrium constants (Kex) for complexes of ligands with Cu2+ and Hg2+ metal picrates between dichloromethane and water have been determined at 25°C. The values of the extraction constants (logKex) were determined to be 12.27, 13.37, 12.94, and 12.39 for Cu2+ and 10.29, 10.62, 11.53, and 11.97 for Hg2+ with L1–L4, respectively.