Fluorides, uses

The direct deterrnination of fluoride using ion-selective electrodes has allowed analysis of fluorspar without the tedious distillation step (see... 

Aluminum Industry. Large amounts of HE are consumed in the production of aluminum fluoride [7784-18-17, AIE, and cryoHte [15096-52-3] (sodium aluminum fluoride), used by the aluminum industry. Both of these compounds are used in the fused alumina bath from which... 

Re OPe . The final step in the chemical processing of rare earths depends on the intended use of the product. Rare-earth chlorides, usually electrolytically reduced to the metallic form for use in metallurgy, are obtained by crystallisation of aqueous chloride solutions. Rare-earth fluorides, used for electrolytic or metaHothermic reduction, are obtained by precipitation with hydrofluoric acid. Rare-earth oxides are obtained by firing hydroxides, carbonates or oxalates, first precipitated from the aqueous solution, at 900°C. 

Refractories in the Aluminum Industry. Carbon materials are used in the HaH-Heroult primary aluminum cell as anodes, cathodes, and sidewalls because of the need to withstand the corrosive action of the molten fluorides used in the process (see Aluminumand aluminum alloys). 

Carbon tetrachloride is used to produce chlorofluorocarbons by the reaction with hydrogen fluoride using an antimony pentachloride (SbCls) catalyst ... 

Stannous fluoride is used in toothpastes and dental rinses to protect tooth enamel from attack by bacteria—cavities (also known as dental caries). It was the first fluoride used for that purpose, in the toothpaste Crest. 

The palladium-catalyzed cross-coupling of alkenylsilanols has been extensively studied with respect to the structure of both the silicon component and the acceptor halide. The preferred catalyst for coupling of aryl iodides is Pd(dba)2 and for aryl bromides it is [allylPdCl]2. The most effective promoter is tetrabutylammonium fluoride used as a 1.0M solution in THF. In general the coupling reactions occur under mild conditions (room temperature, in 10 min to 12 hr) and some are even exothermic. 

C21-0089. The fluorides BF3, AIF3, SiFq, and PF5 are Lewis acids. They all form very stable fluoroanions when treated with lithium fluoride. In contrast, three other fluorides, CF4, NF3, and SFg, do not react with lithium fluoride. Use Lewis acid-base concepts to explain this behavior. 

A mixture of the 2 fluorides, used at low temperature to prepare bis(pentafluoro-sulfur) oxide, is described as possibly explosive. 

Hafnium-centered Lewis acid usage is limited in organic chemistry, because of its lower availability and its similarity to zirconium. There are some reactions, however, for which HfIV compounds are used as effective activators. Glycosylation of glycosyl fluorides using a combination... 

In the fifth paper of this chapter on cathodes, an investigation of thin-film oxide-hydroxide electrodes containing Cr, Ni, and Co compounds was authored by N. Vlasenko et al. The thin-films were produced by electrochemical deposition from transition metal aqueous fluorine-containing electrolytes onto steel substrates. These thin-films were tested in Li coin cells. Electrochemical activity appears to scale with the amount of fluoride used in the deposition the larger concentration of fluoride in the bath, the greater the capacity. One Ni oxide-hydroxide film electrode showed greater than 175 mAh/g reversible capacity on the 50th cycle with excellent coulombic efficiency. 

CobaltCII) ferrate, uses, 7 24 It CobaltCII) fluoride, uses, 7 239t CobaltCIII) fluoride, 7 232-233 uses, 7 239t... 

The conversion of acyl chlorides, sulphonyl chlorides and phosphoryl chlorides into the corresponding fluorides using potassium fluoride in the presence of a quaternary ammonium salt has been recorded [44-47]. Optimum yields are obtained when the dry potassium fluoride contains ca. 1% water. 

Uses. Constituent of alloys with other metals (tin, lead, copper) sulfides used in compounding of rubber and manufacture of pyrotechnics trioxide used as a fire retardant in plastics, rubbers, textiles, and paints chlorides used as coloring agents and as catalysts fluorides used in organic synthesis and pottery manufacmre... 

The radiosynthesis of p F]FDG is based on the nucleophilic substitution of a modified mannose precursor with [ F]fluoride used as the nucleophilic reagent (Fig. 3). 

This approach may not account for all the fluoride released by glass-ionomers [252], A recent study has used two methods of decomplexation of fluoride, using the same solutions for both methods, by dividing a given storage volume into two and treating each aliquot differently. One aliquot was diluted with an equal volume of TISAB, as is usual in the determination of fluoride by ion-selective electrode. The other solution was treated with a small volume of 4 M hydrochloric acid, allowed to stand for 3 h, then neutralised with an equal amount of 4 M sodium hydroxide. A volume of TISAB equal to the initial volume of the aliquot was added. This technique is known to liberate fluoride from monofluorophosphate as well as from aluminofluoride complexes [253],... 

Total fluorine in fluoride supplements and dental products could be determined with minimal samples pre-treatment as for example by direct acid extraction or heating in TISAB buffer solution and subsequent determination of fluoride using fluoride ISE for the reason that entire fluorine, in these products, should be, by definition, available as free inorganic fluoride. 

World Health Organization (WHO) Expert Committee on Oral Health Status and Fluoride Use, Fluorides and Oral Health Report of a WHO Expert Committee on Oral Health Status and Fluoride Use, WHO Technical Report Series 846, World Health Organization, Geneva, 1994. 

M.A. Wade, S.S. Yamamura, Microdetermination of fluoride using an improved distillation procedure. Anal. Chem. 37 (1965) 1276-1287. 

Beryllium (Glucinum) Fluoride, BeF2, mw 47 01, colorless, poisonous pdr, sp gr 2.0l at 15°, mp 800° bp — sublimes v sol in w sol in ale, acids and alkalies. Can be prepd by thermal decomph (at 900—950°) of ammonium beryllium fluoride. Used in production of beryllium metal by reduction with Mg metal Refs 1) Gmelin-Kraut System Number 26(1930), 105 2) Hackh sDict (1944), 123-R 3) Cond-... 

HF In die presence of fluorinating agents, such. as antimony tri- and penta-fluorides. Used as aerosol propint, refrigerant and fire extinguisher... 

Some Aromatic Amines, Anthraquinones and Nitroso Compounds, and Inorganic Fluorides Used In Drinking-water and Dental Preparations 1982 341 pages... 

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