skip to main content

Title: Controlling Cesium Cation Recognition via Cation Metathesis within and Ion Pair Receptor

Ion pair receptor 3 bearing an anion binding site and multiple cation binding sites has been synthesized and shown to function in a novel binding-release cycle that does not necessarily require displacement to effect release. The receptor forms stable complexes with the test cesium salts, CsCl and CsNO{sub 3}, in solution (10% methanol-d{sub 4} in chloroform-d) as inferred from {sup 1}H NMR spectroscopic analyses. The addition of KClO{sub 4} to these cesium salt complexes leads to a novel type of cation metathesis in which the 'exchanged' cations occupy different binding sites. Specifically, K{sup +} becomes bound at the expense of the Cs{sup +} cation initially present in the complex. Under liquid-liquid conditions, receptor 3 is able to extract CsNO{sub 3} and CsCl from an aqueous D{sub 2}O layer into nitrobenzene-d{sub 5} as inferred from {sup 1}H NMR spectroscopic analyses and radiotracer measurements. The Cs{sup +} cation of the CsNO{sub 3} extracted into the nitrobenzene phase by receptor 3 may be released into the aqueous phase by contacting the loaded nitrobenzene phase with an aqueous KClO{sub 4} solution. Additional exposure of the nitrobenzene layer to chloroform and water gives 3 in its uncomplexed, ion-free form. This allows receptor 3 to bemore » recovered for subsequent use. Support for the underlying complexation chemistry came from single-crystal X-ray diffraction analyses and gas-phase energy-minimization studies.« less
Authors:
 [1] ;  [1] ;  [2] ;  [2] ;  [2] ;  [3] ;  [1] ;  [1] ;  [4]
  1. University of Texas, Austin
  2. ORNL
  3. Kangwon National University, Korea
  4. University of Texas
Publication Date:
OSTI Identifier:
1035534
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the American Chemical Society; Journal Volume: 134; Journal Issue: 3
Research Org:
Oak Ridge National Laboratory (ORNL)
Sponsoring Org:
SC USDOE - Office of Science (SC)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ANIONS; BEARINGS; CATIONS; CESIUM; CHEMISTRY; CHLOROFORM; ION PAIRS; NITROBENZENE; WATER; X-RAY DIFFRACTION