Potassium cobalt fluoride

By fusing cobalt chloride with potassium hydrogen fluoride and boric oxide, two borates have been obtained, namely, 2CoO.B203 and 3CoO.B2Os, the latter as rose-coloured rhombic crystals.7... 

Silicon Alkali carbonates, calcium, chlorine, cobalt(II) fluoride, manganese trifluoride, oxidants, silver fluoride, sodium-potassium alloy... 

Cobalt Perchloryl fluoride Chloroacetophenone Potassium cyanide... 

The cobalt complex is usually formed in a hot acetate-acetic acid medium. After the formation of the cobalt colour, hydrochloric acid or nitric acid is added to decompose the complexes of most of the other heavy metals present. Iron, copper, cerium(IV), chromium(III and VI), nickel, vanadyl vanadium, and copper interfere when present in appreciable quantities. Excess of the reagent minimises the interference of iron(II) iron(III) can be removed by diethyl ether extraction from a hydrochloric acid solution. Most of the interferences can be eliminated by treatment with potassium bromate, followed by the addition of an alkali fluoride. Cobalt may also be isolated by dithizone extraction from a basic medium after copper has been removed (if necessary) from acidic solution. An alumina column may also be used to adsorb the cobalt nitroso-R-chelate anion in the presence of perchloric acid, the other elements are eluted with warm 1M nitric acid, and finally the cobalt complex with 1M sulphuric acid, and the absorbance measured at 500 nm. 

C03-0067. Write chemical formulas for these compounds (a) sodium sulfate (b) potassium sulfide (c) potassium dihydrogen phosphate (d) cobalt(II) fluoride tetrahydrate (e) lead(IV) oxide (Q sodium hydrogen carbonate and (g) lithium perbromate. 

When nitryl fluoride is passed at ambient temperature over molybdenum, potassium, sodium, thorium, uranium or zirconium, glowing or white incandescence occurs. Mild warming is needed to initiate similar reactions of aluminium, cadmium, cobalt, iron, nickel, titanium, tungsten, vanadium or zinc, and 200-300°C for lithium or manganese. 

As a starting material, tetrahydrofuran has little to recommend it except in rare cases, one of which is the preparation of fluorofurans. With cobalt(III) fluoride, tetrahydrofuran yields a mixture of polyfluoro derivatives from which alkali fusion removes HF leaving various fluorofurans including tetrafluorofuran and 2,3,4-trifluorofuran (1). Potassium tetrafluorocobaltate acts on tetrahydrofuran giving 2 as the main product and alkali fusion converts this into 2,5-difluorofuran. The fluorofurans all polymerize readily and are rather unresponsive to electrophilic reagents.17... 

Major constituents (greater than 5 mg/L) Minor constituents (O.Ol-lO.Omg/L) Selected trace constituents (less than 0.1 mg/L) Bicarbonate, calcium, carbonic acid, chloride, magnesium, silicon, sodium, sulfate Boron, carbonate, fluoride, iron, nitrate, potassium, strontium Aluminum, arsenic, barium, bromide, cadmium, chromium, cobalt, copper, gold, iodide, lead, Uthium, manganese, molybdenum, nickel, phosphate, radium, selenium, silver, tin, titanium, uranium, vanadium, zinc, zirconium... 

The vendor claims that the following metals have been successfully treated to parts per biUion (ppb) and detection limit levels aluminum, arsenic, cadmium, chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel, selenium, silver, tin, uranium, vanadium, and zinc. The system is also able to remove ammonia, nitrates, phosphates, potassium, fluorides, and sodium. Studies have also been performed using Aqua-Fix to remove radionuchdes such as uranium from waste streams. 

Ethane30 over cobalt(III) fluoride at 165=C gives mainly pentafluoroethane (38%) and hexafluoroethane (40%), together with small amounts of all the other possible C2FnH6 n isomers. In a batch reactor at 100°C, 1,1-difluoroethane (26%). 1,2-difluoroethane (30%), and 1,1,2-trifluoroethane (30%) arc the major products.25 Potassium tetrafluorocobaltate(III) is much less reactive than cobalt(III) fluoride and even at 420 C mainly gives30 a lower degree of fluorination 1,2-difluoroethane (25%), 1,1-difluoroethane (11%), 1,1,2-trifluoroethane (29%), and 1,1,2,2-tetrafluoroethane (10%). 

Fluorination of 1.1,1,2-tetrafluoroethane shows17 that cobalt(lll) fluoride is more reactive than potassium hexafluoronickelate(III). 

Potassium hexafluoronickelate(IV), rhombohedral nickel(III) fluoride, and nickel(lV) fluoride are exceedingly powerful fluorinating agents, more powerful than cobalt(III) fluoride. In solution or suspension in anhydrous hydrogen fluoride at room temperature, they will convert58 the cyclohexyl compound 22 into 23 (R —NiF, or NiF4) and 24 (K2NiF6). 

Silver(II) fluoride and potassium tetrafluoroargentate(III) have similar reactivities towards benzene,11 and appear to be slightly less reactive than cobalt(III) fluoride a similar range of products is formed. Potassium hexafluoronickelate(IV) is slightly more reactive than cobalt(III) fluoride under vapor-phase conditions18 (sec above for reactions of K2NiF6 in anhyd HF) the products are similar to those from cobalt(III) fluoride except that more unsaturates are detected, mainly the ones that predominated in the manganese(III) fluoride fluorination. 

The tetrafluorocobaltates of the alkali metals show12 considerable differences in their reactions with benzene. Lithium tetrafluorocobaltate(III) at 100-130 C gives 3,3,6,6-tetra-fluorocyclohexa-1,4-diene (13) of over 90% purity. This compound has long been postulated1,549 as a major intermediate in the fluorination with cobalt(III) fluoride. The sodium, potassium, and rubidium salts give similar product mixtures (ca. 8 compounds), most being polyfluoroenes (e.g. 14, 8% 15, 12% 16, 35%). 

Tetrahydrofuran is partially fluorinated over cobalt(III) fluoride81 and potassium tetra-fluorocobaltate(III).82 With cobalt(III) fluoride at 100-1 IO C,27 products are obtained with an overall yield of about 50 60%. Most are polyfluorooxolanes 2-4, and the rest (13% of the product mixture) polyfluoropropanes. The major products are 2 (15%), 3 (29%), and 4 (29%) (since the various stereoisomers are equilibrated at the positions next to oxygen in the fluorination process, the total percentages for each set of constitutional isomers are shown, and not the percentages for each stereoisomer). 

Potassium tetrafluorocobaltate(III) at 200°C reacts with tetrahydrofuran to give82 unsaturated products the major ones are 5 and 6, although the overall yield is poor (< 30%). Furan itself gives no products at all over cobalt(IIl) fluoride it presumably polymerizes. This does not, however, rule furan out as an intermediate in the tetrahydrofuran fluorinations (it could form by desaturation, as does benzene in the fluorination of cyclohexane, vide supra). 2-Methyl-and 2,5-dimethyltetrahydrofuran83 have also been fluorinated with similar results to tetrahydrofuran. 

Dioxane is partially fluorinated84 over cobalt(lll) fluoride and potassium tetra-fluorocobaltate(III). With cobalt(III) fluoride at 100°C yields are poor (ca. 15%), and the major products are 7-10 (as with the oxolanes, equilibrium occurs between the stereoisomers during the fluorination). With potassium tetrafluorocobaltate(III) at 220°C, compound 11 comprises 61 % of the product mixture in an overall yield of about 40%. 

Oxathiane has only been fluorinated84 over potassium tetrafluorocobaltate(III) (vide infra). and this gives products very similar in structure to those formed in the dioxane/cobalt(Hl) fluoride fluorination. 

However, hexafluoroacetone is broken down almost completely87 over potassium tetrafluoro-cobaltate(III) at 250°C only traces of trifluoroacetyl fluoride are detected, the rest being carbon tetrafluoride and carbonyl difluoride. This shows that even if perfluoro ketones are formed in fluorination processes, they will break down, thus demonstrating that transition metal fluoride fluorination will not produce polyfluoro ketones. 

Esters and acid fluorides give88 product mixtures very similar to those produced from ketones. Cobalt(III) fluoride again causes complete degradation, but potassium tetrafluoro-cobaltate(lll) gives polyfluoro acid fluorides, which are isolated by conversion to their ethyl esters yields are poor (ca. 20%) in all cases. Methyl propanoate reacts with potassium tetra-fluorocobaltate(III) at 350 CC to give a 5 2 2 mixture of ethyl 2,2-difluoropropanoate, ethyl... 

Methyl-1 //-pyrrole gives93 a very similar product mix Over cobalt(III) fluoride at 140 C to 1-methylpyrrolidine,92 suggesting that the latter is converted to the former by some sort of desaturation reaction. Fluorination over potassium tetrafluorocobaltate(III) at 220 C gives a similar result.93... 

Pyridine and the methylpyridines are fluorinated over cobalt(III) fluoride, potassium tetra-fluorocobaltate(III) and cesium tetrafluorocobaltate(III). Only in the cesium tetrafluorocobalt-ate(III) reactions are significant quantities of polyfluoropyridines and -methylpyridines isolated. 

Using cobalt(III) fluoride at 150 , pyridine gives94 mainly perfluoro(l-methylpyrrolidine) and its 3H derivative, together with a small quantity of an open-chain compound. With potassium tetrafluorocobaltate(III),94 95 open-chain compounds predominate, the main ones being perfluoro(A-methylbutan-l-imine) and 2//,3//-heptafluoro(Af-methylbut-2-en-l-imine). Also formed are smaller amounts of polyfluorinated 1-methylpyrrolidines (ca. 5 % of the product mixture) and polyfluoropyridines (ca. 10%). 4-Methylpyridine gives95 only open-chain products, akin to those formed from pyridine, over potassium tetrafluorocobaltate(III) at 200-220 CC. 

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