Nickel oxide fluorides

For cobalt, rhodium, nickel, palladium, silver, and gold no oxide fluorides have been reported. 

Apparatus aad Reagents. A nickel vacuum line was used. It had a mercury diffusion pump, a mechanical pump, and soda-lime scrubbers (for removal of fluorine, HF, and oxidizing fluorides) and was equipped with a Monel Acco Helicoid pressure gauge (0-1400 Torr, 0.3%) and nickel valves with Teflon packing. Teflon FEP reaction vessels (18 mm o.d.) equipped with Teflon valves were used for all preparations. Agp2 (99.5% purity Fluka, Buchs, Switzerland) was used as supplied. KrFj... 

Nickel boride (Ni B) Nickel boride (Ni B) Nickel(II) bromide Nickel(II) chloride Nickel(II) fluoride Nickel(II) iodide Nickel(II) oxide Nickel(II) sulfide Nickel disulfide Nickel subsulfide Niobium... 

Fireclay bricks (alumina silica bricks, alumina calcium oxide silica bricks, and other silicate bricks) are not optimal barrier materials for A1 reductirMi cells. As we have mentioned, cryolite-based electrolyte for A1 reduction is a substance that dissolves alumina better than anything else. Certainly, it will dissolve all alumina-based refractory compositions and almost all other oxides similar in chemical structure to alumina. From a chemical point of view, the effective refractory barriers against the penetration of cryolite might be tin oxide, nickel oxide, compounds of nickel oxide, iron oxide, or zinc oxide (such as spinel Fe NiOs). These oxides almost do not react with NaF and aluminium fluoride [175]. Yet the cost of these materials, which is 50-100 times higher than that of firebrick, provides the impetus to find less costly variants of alumina silica materials. 

Further improvements in anode performance have been achieved through the inclusion of certain metal salts in the electrolyte, and more recently by dkect incorporation into the anode (92,96,97). Good anode performance has been shown to depend on the formation of carbon—fluorine intercalation compounds at the electrode surface (98). These intercalation compounds resist further oxidation by fluorine to form (CF ), have good electrical conductivity, and are wet by the electrolyte. The presence of certain metals enhance the formation of the intercalation compounds. Lithium, aluminum, or nickel fluoride appear to be the best salts for this purpose (92,98). 

Oxidative Fluorination of Aromatic Hydrocarbons. The economically attractive oxidative fluorination of side chains in aromatic hydrocarbons with lead dioxide or nickel dioxide in Hquid HF stops at the ben2al fluoride stage (67% yield) (124). 

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