Fluorides carbon

Fluor-jod, n. iodine fluoride, -kalium, n. potassium fluoride, -kalzium, n. calcium fluoride, -kiesel, m. silicon fluoride, -kie-selsaure,/. fluosilicic acid, -kohlenstoff, m. carbon fluoride, -lithium, n. lithium fluoride. -metall, n. metallic fluoride, -natrium, n. sodium fluoride, -phosphat, n. fluophosphate. -phosphor, m. phosphorus fluoride, -salz, n. fluoride, -schwefel, m. sulfur fluoride, -selen, n. selenium fluoride, -silber, n. silver fluoride, -silikat, n. fluo-silicate. -silizium, n. silicon fluoride, -sili-ziumverbindung, /. fluosilicate. -tantal-sMure, /. fluotantalic acid, -tellur, n. tellurium fluoride, -titan, n. titanium fluoride, -toluol, n. fluorotoluene, fluotoluene. 

Precipitation Processes. Plutonium peroxide precipitation is used at Rocky Flats to convert the purified plutonium nitrate solution to a solid (14) the plutonium peroxide is then calcined to Pu02 and sent to the reduction step. The chemistry of the plutonium peroxide precipitation process is being studied, as well as alternative precipitation processes such as oxalate, carbonate, fluoride, and thermal denitration. The latter method shows the most promise for cost and waste reduction. 

The heats of substituted Group IVA fluorides (Table XXI) illustrate these points. All the substituted carbon fluorides are less stable than calculated from additivity, with destabilization increasing roughly... 

Examples of the Michael-type addition of carbanions, derived from activated methylene compounds, with electron-deficient alkenes under phase-transfer catalytic conditions have been reported [e.g. 1-17] (Table 6.16). Although the basic conditions are normally provided by sodium hydroxide or potassium carbonate, fluoride and cyanide salts have also been used [e.g. 1, 12-14]. Soliddiquid two-phase systems, with or without added organic solvent [e.g. 15-18] and polymer-supported catalysts [11] have been employed, as well as normal liquiddiquid conditions. The micellar ammonium catalysts have also been used, e.g. for the condensation of p-dicarbonyl compounds with but-3-en-2-one [19], and they are reported to be superior to tetra-n-butylammonium bromide at low base concentrations. 

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... 

Butyrolactone is the preferred solvent of Japanese workers for primary batteries with carbon fluoride cathodes, although the K of the electrolyte at 45 shows a maximum of only 9 x 10 ohm cm . The preparation of (CF ) and the ED dependence on the value of X in (CFx) are reported (33,34). 

The two copper oxide layers can be considered as polymeric since the covalent character is in the same range as for the carbon fluoride bond in Teflon. Thus, the 123-superconductors consist of two types of polymeric copper oxide layers held together by ionic bonding metals such as barium and yttrium. This theme of polymeric layers held together by ionic bonding to metals is common in the silicates and other minerals. 

Carbon fluoride [also known as carbon monofluoride, polycarbon monofluoride, graphite fluoride, or (CFx)n] is a solid, layered, non-stoichiometric fluorocarbon of empirical formula CFX, where 0 < x < 1.25, obtained by the action of elemental fluorine on carbon. Fluorine combines with carbon and yields three solid compounds CFX, C2FX, and C4FX as well as varying amounts of volatile fluorocarbons as byproducts. With appropriate selection of fluorination conditions nearly 100% conversion of carbon to carbon tetrafluoride can occur. 

Carbon materials used for the commercial synthesis of carbon fluoride include natural graphite, petroleum coke, activated carbon, carbon black and carbon fiber. Experimental carbon materials include residual carbon, exfoliated graphite, fullerenes and other unique carbons and carbon inserts. The degree of graphitization of carbon material varies continuously, so it is not simple to define the exact boundary between carbon and graphite. The product formed... 

Table 1. Synthesis of Graphite Fluorides and Carbon Fluorides...

Table 2. X-ray Diffraction Data of Graphite, Graphite Fluoride, and Carbon Fluoride...

One of the growing applications of carbon fluorides is in the field of lubrication where the surface area of CFX comes into play. The surface area for various CFX, produced from graphite jt 1. is shown in Table 4. The results show that the surface area is proportional to the degree of fluorination.12... 

The mechanistic borderline between E2 and ElcB mechanisms has been studied under various conditions.1,2 The mechanism of the elimination reaction of 2-(2-fluoroethyl)-1-methylpyridinium has been explored explored by Car-Parrinello molecular dynamics in aqueous solution.3 The results indicated that the reaction mechanism effectively evolves through the potential energy region of the carbanion the carbon-fluoride bond breaks only after the carbon-hydrogen bond. 

Carbon tetrafluoride is formed by passing gaseous fluorine over finely divided carbon (Norit).1 Sugar charcoal especially, and some wood charcoals, give large amounts of higher carbon fluorides and are to be avoided if the lower fluorides are desired. Norit seems to be the best when large yields of carbon tetrafluoride are desired. 

The moderate-temperature cell has advantages where its use is required continuously, where anhydrous hydrogen fluoride is available, where fluorine free from all traces of carbon fluorides is required, and where it is operated by experienced and competent workers. Its advantages are that only a moderate temperature is used and the regeneration of the electrolyte is simplified in that large quantities of water need not be removed. 

For ordinary laboratory purposes and for intermittent use, the high-temperature cell seems to have some advantages. It is the least expensive to build and does not require the use of anhydrous hydrogen fluoride in the preparation or regeneration of the electrolyte. As the fresh electrolyte does not readily absorb water, the cell may be left exposed to the ordinary laboratory air for days and still generate fluorine almost immediately when put into operation. Its use is attended by little danger, and it requires only a small amount of auxiliary apparatus. The fluorine contains as an impurity small amounts of carbon fluorides from the reaction with the graphite anode. 

The gas escaping at the anode contains about 90 % Fa after the hydrogen fluoride has ]jeen condensed by cooling the remainder consists of oxygen, carbon dioxide, silicon tetrafluoride and carbon fluorides. At an anode current density of 10 A per sq. dm current efficiency equals 95 to 99 per cent. The output of one cell is on the average 1 kg of fluorine per hour. The electrolyte content lasts about one year and then it must be replaced. 

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