Caesium compounds using

The e.s.r. spectra of phosphorus compounds have been reviewed.101 The phosphorus hyperfine splitting (ap 33.5 G) of the radical anion (77) is within the 25—36 G range of phosphorin radical anions.102 The cis- and fra/w-isomers of 1,2-bisdiphenylphos-phinoethylene gave the same radical anion (78). The unpaired electron is coupled to all the protons in the molecule as well as to the two phosphorus atoms, and shows that the electron is completely delocalized. Only when caesium was used as the gegenion in THF could a metal interaction be detected. The spectrum in this case corresponded to the association of two caesium ions with the radical anion, the third... 

Caesium compounds find application in pyrotechnic formulations to provide a source of near IR radiation for night vision devices which are widely used as electro-optical equipment for surveillance, searching and tracking in the near IR(NIR) region of the electromagnetic spectrum. Lohkamp suggested the use of... 

Caesium and its compounds are more rare than rubidium, Salts of caesium are used as reagents in microchemistry. The metal was quoted (1911-13) at 1.75 to 2.25 per quarter gram and the chloride at 30 cents per gram, but the material is difficult to obtain at almost any price. 

The /3-ketoesters [RC(0 ) CIIC(0)0R] are close analogs which also chelate effectively. A useful general method for synthesis of Co11 compounds of these molecules has been reported, which uses the lithium, caesium, or trimethylsilyl enolate of the /3-ketoester reacting with a Co11 salt in tetrahydrofuran.427... 

Uses Of the Stassfurt salts.—The magnesium compounds in the Stassfurt salts are used for the preparation of magnesium and of its salts. The potash salts are an essential constituent of many fertilizers used in agriculture, etc. 22 and potassium chloride is the starting-point for the manufacture of the many different kinds of potassium salts used in commerce—carbonate, hydroxide, nitrate, chlorate, chromate, alum, ferrocyanide, cyanide, iodide, bromide, etc. Chlorine and bromine are extracted by electrolysis and other processes from the mother liquids obtained in the purification of the potash salts. Boric acid and borax are prepared from boracite. Caesium and rubidium are recovered from the crude carnallite and sylvite. 

Subsequently, in 1860, Bunsen demonstrated that the colouring of the flames used as a means of identifying certain salts was due to the element and not the compound to which it was bound. The power of this new method led him to discover two unknown elements in mineral water caesium and rubidium. Other researchers then soon discovered thallium, indium, gallium and germanium, elements for which lines are emitted in the visible domain. 

On the synthetic side, single diastereomers of P-keto phosphine oxides have been generated from intermolecular acylation of phosphine oxides using either chiral esters or chiral phosphine oxides. In most cases, reduction of the ketone products was not affected by the presence of extra chiral centres. Addition of metallated phosphine oxides to proline-derived ketoaminals provides a new route to optically active P-hydroxy phosphine oxides. The P-hydroxy phosphine oxide 97 has been prepared by the caesium fluoride mediated reaction of silyl-substituted phosphine oxide 98 and benzaldehyde." The synthesis of two (E)-(6-hydroxy-2-hexen-l-yl)diphenylphosphine oxides (99) has been reported. The Horner-Wittig reactions of these compounds with various carbonyl compounds... 

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