Caesium, powder

Main uses. Caesium metal is used in the production of vacuum tubes as a scavenger to reduce residual gaseous impurities after the tubes have been sealed. Cs may be generated in situ by heating a pellet of caesium chromate mixed with a metal powder (Zr, Ca, Ba). Cs metal is used as the propellant in ion thrusters (employed in satellites for orientation control) it is ionized in a vacuum chamber, the Cs+ are then accelerated through a nozzle (high specific impulse because of high atomic mass). 

Of particular interest is Caesium Chlor-ruthenite, Cs,.RuC]6.H20, which Howe4 obtained by the action of hydrochloric acid on ruthenium tetroxide and subsequent addition of caesium chloride to the solution. The salt is precipitated as a dark brown powder, fairly soluble in water and hydrochloric acid, exhibiting the chemical reactions of a trivalent ruthenium salt. Howe also describes an isomeride of this salt, which lie termed, in accordance with Werner s nomenclature, Caesium Aquo-chlor-ruthenate [vide infra). 

Place the caesium carbonate (31.3 g), caesium toluenesulfonate (3.65 g) and tetrabutylammonium iodide (1.13 g) in the reaction vessel through a powder funnel and then pour dry DMF (800 mL) through the same funnel. Degas the resulting suspension with a flow of nitrogen for 15 min. Transfer the nitrogen supply to the bubbler, so that the gas is flowed over the reaction mixture. 

Of these the first-named is readily obtained by adding a solution of caesium chloride to one of sodium heptanitroso ferro-sulphide, when the caesium derivative is precipitated as an insoluble black crystalline powder. The rubidium derivative, obtained in an analogous manner, presents a similar appearance. The thallium salt is likewise difficultly soluble in water, and is obtained by double decomposition with thallium sulphate and the potassium derivative. 

For example, naturally occurring clinoptilolite is used by BNFL to remove radioactive caesium and strontium from spent pile effluent. However, the synthetic zeolites, A and P, have had the greatest impact on the home. Sodium zeolite A rapidly exchanges its sodium atoms for the divalent hard water ions calcium and magnesium at room temperature. This discovery led to the replacement of the polyphosphates previously used in washing powder, which were damaging to the environment, by zeolite A about 20 years ago. More recently, Unilever introduced MAP (maximum aluminium zeolite P) as a replacement for. zeolite A. MAP has a lower water content, and is lighter in the packet ... 

X.-G. Feng, S. Jing, Q.-L. Wu, J. Chen, C. Song, The hydrodynamic behaviour of the liquid-solid circulating fluidized bed ion exchange system for caesium removal, Powder Technol. 134 (2003) 235. 

Gold(V)—Salts of [AuFg] containing the novel An " oxidation state, have been isolated via Scheme 26. Alternatively, the caesium salt can be obtained by direct oxidation of Cs[AuF4] with fluorine. Raman spectra were recorded, and X-ray powder patterns showed the salts to be isomorphous with related [MFg] (M = Ru, Ir or Pt) salts. 

Synonyms Caesium Cesium metal Cesium, powdered... 

Chapman and co-workers have reported the direct spectroscopic observation of benzocyclobutadiene itself by reaction of cis-1,2-di-iodobenzocyclobutene with zinc powder at 230 °C. Initial cooling of the resultant vapour deposited a mixture of dimeric material and traws-l,2-di iodobenzocyclobutene. The benzocyclobutadiene was trapped in an argon matrix at 20 K on either a caesium iodide or a sapphire plate for spectroscopic examination. The infrared spectrum showed a band at 700 cm which is probably due to one of the C—H bond deformations of the four-membered ring. The ultraviolet spectrum showed at 243, 246.5,256, 270, 281.5, and 289 nm. On warming above 75 K, the known benzocyclobutadiene dimer (150) was formed and identified by comparison with authentic material. 

Bowsher, B. R., Dickinson, S. The interaction of caesium hydroxide vapour with iron and ferric oxide (Fe203) powders at 760 °C. Report AEEW-M 2262 (1985)... 

The second paper reports on a preliminary. Y-ray powder study of the difluorodioxocarbonate ion, C02Fj ", which showed that the caesium salt is isostructural with the corresponding CS2BF4 salt, and thus confirms the basic tetrahedral structure of the ion. 

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