Nickel tellurides

Tellur-kohlenstoff, m. carbon telluride. -me-tall, n. metal(lie) telluride. -natrium, n. sodium telluride. -nickel, m. nickel telluride. 

Nickel(II) sulfide, NiS (millerite) nickel(II, III) sulfide, NisSa (polymidite) nickel(III) sulfide, Ni3S2 nickel sulfide, Ni3S2 (heazelwoodite) nickel sulfide, NiS2 (vaesite) nickel selenide, NiSc2 nickel(II) selenide, NiSe nickel telluride, NiTc2 (melonite). 

Nickel sulphate, NiS04.7H20, is occasionally found as the orthorhombic mineral moresonite or pyromelane, and probably results from oxidation of the sulphide. It occurs at Cape Ortegal in Spain, and at Reichelsdorf (Hesse) density 2-0. Nickel telluride, Ni2Te3, is found as melonite in California, in steely grey hexagonal crystals. 

Heavy water, see Hydrogen[ H] oxide Heazlewoodite, see rn-Nickel disulfide Hematite, see Iron(III) oxide Hermannite, see Manganese silicate Hessite, see Silver telluride Hieratite, see Potassium hexafluorosilicate Hydroazoic acid, see Hydrogen azide Hydrophilite, see Calcium chloride Hydrosulfite, see Sodium dithionate(III)... 

The catalyst was prepared from a nickel-aluminum (50 50) alloy using the procedure given by Mozingo. The catalyst is used in large excess. Reduced amounts of catalyst resulted in decreased yields, and the product is contaminated with detectable (gas chromatography) amounts of bis(4-methoxyphenyl) telluride. 

Dimethoxybiphenyl can also be prepared by simply refluxing bis(4-methoxyphenyl)tellurium dichloride with degassed commercial Raney nickel. The yields are, however, lower and less reproducible, and the product may contain some bis(4-methoxyphenyl) telluride. 

A process for the gravimetric determination of mixtures of selenium and tellurium is also described. Selenium and tellurium occur in practice either as the impure elements or as selenides or tellurides. They may be brought into solution by mixing intimately with 2 parts of sodium carbonate and 1 part of potassium nitrate in a nickel crucible, covering with a layer of the mixture, and then heating gradually to fusion. The cold melt is extracted with water, and filtered. The elements are then determined in the filtrate. 

Cathodic deposition of bismuth(in) telluride films has been reported [224] also on copper and nickel foils, from aqueous nitric acid solutions of bismuth oxide and tellurium oxide in molar ratios of Bi Te = 3 3 and 4 3, at 298 K. The... 

When the conditions are controlled properly, Zn can mediate the reduction of the C-C double bond of a, (3-unsaturated carbonyl compounds in the presence of a nickel catalyst in aqueous ammonium chloride (Eq. 10.7). The use of ultrasonication enhances the rate of the reaction.15 Sodium hydrogen telluride, (NaTeH), prepared in situ from the reaction of... 

Sodium hydrogen telluride reacts with epoxides, in accordance with an S 2 displacement, giving rise to telluro-alcohols. These products are useful intermediates since they are easily converted into the corresponding alcohols and ketones by treatment with nickel boride followed by oxidation (reaction (a)) or to alkenes via the corresponding tosylates (reaction b)). ... 

Despite the excess of alkyne used, the transfer of only one vinylic group was observed. A more general approach of this method involves the reaction of (Z,Z)- and (f ,fi)-divinylic tellurides with alkynes under nickel catalysis, to give (Z)- and ( )-enynes with complete retention of configuration."... 

Zinc telluride was obtained by deposition on the nickel electrode from 40 to 60 mol % ZnCl2-EMIC melt containing Te(IV) and PC [181]. The composition of the Zn-Te deposits was dependent on the deposition potential andTe(IV) concentration in the plating solution. 

Binary Selenides. Most binary selenides are formed by heating selenium in the presence of the element, reduction of selenites or selenates with carbon or hydrogen, and double decomposition of heavy-metal salts in aqueous solution or suspension with a soluble selenide salt, eg, Na2Se or (NH Se [66455-76-3]. Atmospheric oxygen oxidizes the selenides more rapidly than the corresponding sulfides and more slowly than the tellurides. Selenides of the alkali, alkaline-earth metals, and lanthanum elements are water soluble and readily hydrolyzed. Heavy-metal selenides are insoluble in water. Polyselenides form when selenium reacts with alkali metals dissolved in liquid ammonia. Metal (M) hydrogen selenides of the M HSe type are known. Some heavy-metal selenides show important and useful electric, photoelectric, photo-optical, and semiconductor properties. Ferroselenium and nickel selenide are made by sintering a mixture of selenium and metal powder. 

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