Cesium ions selective extraction

A unique assembly of a crystalline hybrid supramolecular salt was achieved by reaction of 2,4-bis (3-pyridylmethyl)oxy -(l,3)-p-bu -calix[4]-crown-6 (33), hexadecafluoro-l,8-diidooctane and Csl (2(X) 4951). In its solid state, the cesium ion of the supercation was encapsulated inside the cavity created by the crown ether loop, the picolyl and inverted phenyl moieties, whereas the two iodide ions of the superanion, formed a discrete five component aggregate held together by hydrogen and halogen bonds. Similar adduct existed in solution. A combination of this calix-crown 33 and octafluoro-l,4-diiodobutane acted as an effective binary host for the selective extraction of Csl from aqueous to fluonous phase. 

J.K. Kim, J.S. Kim, Y.G. Shul, K.W. Lee, and W.Z. Oh. Selective extraction of cesium ion with calix[4]arene crown ether through thin sheet supported liquid membranes. Journal of Membrane Science 187 3-11, 2001. 

In an analogous way to the measurement of the electronic absorption spectra of cations, those of anions can be obtained. A sputter source has been used to generate the pure carbon anions. In this, a graphite rod is bombarded with cesium ions. The carbon species are formed by sputtering and gas phase processes and the ions produced are extracted for mass-selection. Sufficient ion concentrations have been attained for the spectroscopic studies of carbon anions in the C4 to CJo range. The carbon species are unusual among anions in that they have large... 

PRINCIPLES OF SOLVENT EXTRACTION OF ALKALI METAL IONS UNDERSTANDING FACTORS LEADING TO CESIUM SELECTIVITY IN EXTRACTION BY SOLVATION Bruce A. Moyer and Yunfu Sun... 

Many types of separation systems other than solvent extraction have been found to exhibit high cesium selectivity. Such systems represent a point of comparison by which the effectiveness of solvent extraction systems may be measured. Table 1 lists some representative examples. These systems include inorganic ion exchangers, precipitation methods, and ion-exchange resins. For a variety of reasons, these materials have considerable potential for, and application in, cesium separations and may for specific tasks be the method of choice in the nuclear industry. The reader may consult the sampling of references cited in Table 1 for further information. 

The very simple macrocycle, the easy-to-prepare system meso-octamethylcalix[4]pyrrole 3, which has been already mentioned in this chapter, can act as both a cation (Cs+) and an anion (Cl or Br ) receptor forming a complex of 1 1 1 cesium calix[4]pyrrole halide stoichiometry, under conditions of aqueous nitrobenzene solvent extraction (Figure 25). Control studies involving nitrate revealed no evidence of ion pairing for CSNO3 under conditions identical to those where it was observed for CsCl and CsBr, thus enlightening the high selectivity of the process. 

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