Proton-ionizable crown compounds. 12. Proton-Coupled selective membrane transport of Li+ using a proton-ionizable pyridono macrocycle |
| |
Authors: | Reed M. Izatt Gypzy C. Lindh Ronald L. Bruening Peter Huszthy John D. Lamb Jerald S. Bradshaw James J. Christensen |
| |
Affiliation: | (1) Departments of Chemistry and Chemical Engineering, Brigham Young University, 84602 Provo, UT, USA |
| |
Abstract: | The macrocycle-mediated fluxes of several alkali metal cations have been determined in a H2O-CH2Cl2-H2O liquid membrane system. Water-insoluble proton-ionizable macrocycles of the pyridono type were used. The proton-ionizable feature allows the coupling of cation transport to reverse H+ transport. This feature offers promise for the effective separation and/or concentration of alkali metal ions with the metal transport being driven by a pH gradient. A counter anion in the source phase is not co-transported. The desired separation of a particular metal ion involves its selective complexation with the macrocycle, subsequent extraction from the aqueous phase to the organic phase, and exchange for H+ at the organic phase-receiving phase interface. Factors affecting transport which were studied include ring size, source phase pH, and receiving phase pH. Lithium was transported at a rate higher than that of the other alkali metals in both single and competitive systems using a 15-crown-5 pyridono carrier. |
| |
Keywords: | Pyridono macrocycles proton-ionizable selective alkali cation transport liquid membrane coupled M+-H+ transport |
本文献已被 SpringerLink 等数据库收录! |