Cesium species

Observed line widths are metal dependent. However, values of j.U5i, the unpaired electron (spin) density at the metal nucleus, are approximately independent of the metal atom for potassium, rubidium, and cesium species. As such, the states a Ma(A = 39, 85, 133) are best described as true hydrogenic states in this disordered medium. 

It is also possible to prepare crystalline electrides in which a trapped electron acts in effect as the anion. The bnUc of the excess electron density in electrides resides in the X-ray empty cavities and in the intercoimecting chaimels. Stmctures of electri-dides [Li(2,l,l-crypt)]+ e [K(2,2,2-crypt)]+ e , [Rb(2,2,2-crypt)]+ e, [Cs(18-crown-6)2]+ e, [Cs(15-crown-5)2]" e and mixed-sandwich electride [Cs(18-crown-6)(15-crown-5)+e ]6 18-crown-6 are known. Silica-zeolites with pore diameters of vA have been used to prepare silica-based electrides. The potassium species contains weakly bound electron pairs which appear to be delocalized, whereas the cesium species have optical and magnetic properties indicative of electron locahzation in cavities with little interaction between the electrons or between them and the cation. The structural model of the stable cesium electride synthesized by intercalating cesium in zeohte ITQ-4 has been coirfirmed by the atomic pair distribution function (PDF) analysis. The synthetic methods, structures, spectroscopic properties, and magnetic behavior of some electrides have been reviewed. Theoretical study on structural and electronic properties of inorganic electrides has also been addressed recently. ... 

The CO2 adsorption capacity of CsO,j/CsX increased Hnearly with the number of excess cesium atoms, but the strength of most adsorption sites seemed to be unaffected by the amount of excess cesium species. The basic strengths were found to vary in the order CsOJCsX > CsO,j/KX > KO,j/KX. However the differential heats at low CO2 coverage were about the same for aU samples. The values of CO2 adsorption capacities from STPD were slightly higher than those from adsorption micro-calorimetry [115]. 

X zeolites exchanged with cesium and impregnated with cesium species were active as catalysts for the Knoevenagel reaction between the aldehyde obtained by the hydro-formylation of limonene and ethyl acetoacetate. The product distribution observed has shown that other reactions were occurring, such as decarboxilation and aldol condensation reactions that also led to products of potential commercial interest. The best results were obtained for the sample with 14 cesium atoms impregnated per unit cell, at 403 K and ethyl acetoacetate / menthene molar ratio of 5. In such a condition, yields of products of interest as intermediates for fine chemicals production were as high as 90% after 4 h of reaction. 

This system is capable of extracting the Cs+ cation from aqueous media with a selectivity over K+ and Na+ that exceeds that displayed by the constituent (monomeric) calixcrown receptor. It was further found that precipitation of the salt-bound form of the polymer, followed by polymer digestion under oxidizing acidic conditions, can be used to isolate the extracted cesium species. 

The data suggest that iodine will be released, predominantly, as cesium iodide under most postulated light water reactor accident conditions. However, formation of more volatile iodine species (e.g., elemental iodine and organic iodines) is not impossible under certain accident conditions. 

NMR spectroscopy is ideal for detecting charged fluorinated intermediates and has been applied to the study of increasingly stable carbocation and carbanion species. Olah [164, 165] has generated stable fluorocarbocations m SbFj/SOjClF at low temperatures The relatively long-lived perfluoro-rerr-butyl anion has been prepared as both the cesium and tris(dimethylamino)sulfonium (TAS) salts by several groups [166, 167, 168], Chemical shifts of fluonnated carbocations and carbanions are listed m Table 23. 

Figure 4.11. Cesium ion initiated static SIMS spectra of platinum species on fresh auto-exhaust catalyst.

Miura reported a 1,4-shift of rhodium in the reaction of norbornene with arylboronic acids (Scheme 3) where rhodium moves from an alkyl sp2-carbon to an aryl sp2-carbon, and the arylrhodium species further reacts with another molecule of norbornene.30 Polyalkylated phenyls are obtained in good yields. Cesium fluoride facilitates the transmetallation, generating the phenylrhodium complex which then coordinates to the -face of norbornene. 

Lasat, M.M., Fuhrmarm, M., Ebbs, S.D., Cornish, J.E., and Kochian, L.V., 1998, Phytoremediation of radiocesium-contaminated sod Evaluation of cesium-137 bioaccumulation in the shoots of three plant species. J. Environ. Qual. 27 165-169. 

Heat capacity data for ions in aqueous solution over the temperature range 25-200°C. Such data for ionic species of uranium, plutonium, other actinides and various fission products such as cesium, strontium, iodine, technetium, and others are of foremost interest. 

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