Fundamental Studies Regarding Synergism Between Calix[4]arene‐bis(<i>tert</i>‐octylbenzo‐crown‐6) and Alcohol Modifiers in the Solvent Extraction of Cesium Nitrate

Abstract

Abstract This work emphasizes the crucial role of polar solvating molecules known as phase modifiers in solvent‐extraction systems. The focus of these studies was the extraction of cesium by calix[4]arene‐bis(tert‐octylbenzo‐crown‐6) in dodecane modified with various lipophilic alcohols. Results of equilibrium modeling are consistent with aggregation of the alcohol molecules with each other and with the calixarene‐cesium nitrate complexes. These modeling results are supported by electrospray mass spectrometry experiments, clearly showing the alcohol:anion adducts containing several alcohol molecules. They are also supported by crystallographic evidence showing the existence of a hexameric aggregate in the solid state for a derivative of one of the alcohol modifiers used for solvent extraction, in agreement with the species giving the best modeling results. Acknowledgements The submitted manuscript has been authored by a contractor of the U.S. Government under contract DE‐AC05‐00OR22725. Accordingly, the U.S. Government retains a nonexclusive, royalty‐free license to publish or reproduce the published form of this contribution, or allow others to do so, for U.S. Government purposes. This research was sponsored by the Division of Chemical Sciences, Geosciences, and Biosciences, Office of Basic Energy Sciences, U.S. Department of Energy, under contract number DE‐AC05‐00OR22725 with Oak Ridge National Laboratory, managed and operated by UT‐Battelle, LLC. The authors thank Dr. Gary J. Van Berkel for assistance with electrospray mass spectrometry.