Cerium oxide chloride

The cerium concentrate derived from bastnasite is an excellent polish base, and the oxide derived direcdy from the natural ratio rare-earth chloride, as long as the cerium oxide content is near or above 50 wt %, provides an adequate glass poHsh. The polishing activity of the latter is better than the Ce02 Ln0 ratio suggests. Materials prepared prior to any Ln purification steps are sources for the lowest cost poHshes available used to treat TV face plates, mirrors, and the like. For precision optical polishing the higher purity materials are preferred. 

Two tandem alkene metathesis-oxidation procedures using Grubb s second-generation ruthenium catalyst resulted in unique functional group transformations. Use of sodium periodate and cerium(III) chloride, in acetonitrile-water, furnished cis-diols. Oxidation with Oxone, in the presence of sodium hydrogencarbonate, yielded a-hydroxy ketones.296 Secondary alcohols are oxidized to ketones by a hydrogen... 

The cerium oxide obtained on calcination is treated with nitric acid and then hydrolysed in the presence of sulfate to give basic sulfate of 99.9% purity. The cerium-free rare earth chlorides are subjected to a solvent extraction step to produce a samarium concentrate as shown in Fig. 1.15. 

A sulfuric acid solution of cerium(IV) is nearly as potent an oxidizing reagent as is permanganate and can be substituted for the latter in most of the applications described with potassium permanganate. Cerium(IV) does not oxidize chloride ion at a detectable rate as does permanganate, and the reagent is indefinitely stable. On the other hand, the color of cerium(IV) is not sufficiently intense to serve as an indicator. In addition, the reagent cannot be used in neutral or basic solutions. 

Chemicae Eormulas Common compounds o Cerium oxide CeiOs o Gadolinium oxide Gd203 o Lanthanum oxide LaiOs o Yttrium oxide Y2O3 o Cerium nitrate Ce(N03)3 o Cerium chloride CeCls... 

The reaction with CeOj was incorrectly reported as yielding CeCl [360]. Cerium(IV) oxide reacts with phosgene to initially form cerium(lll) oxide chloride, which can then react with further phosgene (see Section 9.3.1). Thus, the stoicheiometry of the two possible overall reactions is [307,1088,2042] ... 

A 1.5 M solution of cerium (III) chloride was poured together with a 1 M ammonium hydroxide solution in the HUSY suspension at pH 8, forming a precipitate of a cerium (III) hydroxide which, after calcination at 873K for 2 h, was transformed in cerium(IV) oxide. 

One of the limitations of the Warren s adaptation of Homer-Wittig olefina-tion, the failure of the (Z)-selective route when the alkene has a branched chain substituent, has now been overcome. Reduction of the p-ketophosphonates carrying a-branches, e.g. (112) and (113), with sodium borohydride and cerium chloride gives excellent a / -stereoselectivity and hence (Z)-alkene on base-induced elimination. Enantioselective synthesis of both jy -(115) and anti- ll) P-hydroxy-phosphine oxides has been achieved with up to 90% e.e. through two separate approaches. The jyn-isomer was obtained by reduction of the corresponding ketone (114), while the anti-isomer is the product of the reaction of the oxazolidine substituted aldehyde (116) with lithiated diphenylmethyl-phosphine oxide (Scheme 10). A new, highly stereoselective approach to trisubstituted alkenes has been reported. Cerium(III) chloride-promoted... 

Cerium(III) chloride CeCl3 +2490 Dysprosium(III) oxide Dy203 +89600... 

Cerium oxide Chromic acid Chromium chloride (ous) Chromium dioxide Chromium hydroxide (ic)... 

Manganese oxide (ous) catalyst, alphabromination Phosphorus, yellow catalyst, alphachlorination Sulfur chloride catalyst, alumina Cerium oxide catalyst, ammonia... 

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