Carbides halogens

The mono- and di-alkali metal acetylides, copper acetylides, iron, uranium and zirconium carbides all ignite in chlorine, the former often at ambient temperature. See Caesium acetylide Halogens Dicopper(I) acetylide Halogens Iron carbide Halogens... 

Dicopper(l) acetylide Halogens Iron carbide Halogens... 

J. C. Million, C. W. Weber, and P. R. Kuehn, Gas Chromatography of Some Corrosive Halogen-Containing Gases, Report No. K-1639, Union Carbide Corp., Nuclear Division, New York, 1966. 

Hafnium carbide is inert to most reagents at room temperature, but is dissolved by hydrofluoric acid solutions which also contain an oxidising agent. Above 250°C, hafnium carbide reacts exothermically with halogens to form hafnium tetrahaUde, and above 500°C, with oxygen to form hafnium dioxide. At higher temperatures in a flow of hydrogen, hafnium carbide slowly loses some of its carbon. 

Dkect synthesis is the preparative method that ultimately accounts for most of the commercial siUcon hydride production. This is the synthesis of halosilanes by the dkect reaction of a halogen or haUde with siUcon metal, siUcon dioxide, siUcon carbide, or metal sihcide without an intervening chemical step or reagent. Trichlorosilane is produced by the reaction of hydrogen chloride and siUcon, ferrosiUcon, or calcium sihcide with or without a copper catalyst (82,83). Standard purity is produced in a static bed at 400—900°C. 

Zirconium carbide is inert to most reagents but is dissolved by hydrofluoric acid solutions which also contain nitrate or peroxide ions, and by hot concentrated sulfuric acid. Zirconium carbide reacts exothermically with halogens above 250°C to form zirconium tetrahaHdes, and with oxidizers to zirconium dioxide in ak above 700°C. Zirconium carbide forms soHd solutions with other transition-metal carbides and most of the transition-metal... 

Zirconium tetraiodide [13986-26-0], Zrl, is prepared directly from the elements, by the reaction of iodine on zirconium carbide, or by halogen exchange with aluminum triiodide. The reaction of iodine with zirconium oxide and carbon does not proceed. The physical properties are given in Table 7. 

Whereas finely divided cobalt is pyrophoric, the metal in massive form is not readily attacked by air or water or temperatures below approximately 300°C. Above 300°C, cobalt is oxidized by air. Cobalt combines readily with the halogens to form haUdes and with most of the other nonmetals when heated or in the molten state. Although it does not combine direcdy with nitrogen, cobalt decomposes ammonia at elevated temperatures to form a nitride, and reacts with carbon monoxide above 225°C to form the carbide C02C. Cobalt forms intermetallic compounds with many metals, such as Al, Cr, Mo,... 

Carbon forms binary compounds with most elements those with metals are considered in this section whilst those with H, the halogens, O, and the chalcogens are discussed in subsequent sections. Alkali metal fullerides and encapsulated (endohedral) metallafullerenes have already been considered (pp. 285, 288 respectively) and met-allacarbohedrenes (metcars) will be dealt with later in this section (p. 300). Silicon carbide is discussed on p. 334. General methods of preparation of metal carbides are ... 

Silicon and silicon carbide both react readily with all the halogens to form colourless... 

Chemical Resistance. Boron carbide resists oxidation in air up to 600°C due to the formation of a film of B2O3. Its chemical resistance is generally excellent although it reacts with halogens at a high temperature. 

Silicon, like carbon, is relatively inactive at ordinary temperatures. But, when heated, it reacts vigorously with the halogens (fluorine, chlorine, bromine, cmd iodine) to form halides and with certain metals to form silicides. It is unaffected by all acids except hydrofluoric. At red heat, silicon is attacked by water vapor or by oxygen, forming a surface layer of silicon dioxide. When silicon and carbon are combined at electric furnace temperatures of 2,000 to 2,600 °C (3,600 to 4700 °F), they form silicon carbide (Carborundum = SiC), which is an Importeint abrasive. When reacted with hydrogen, silicon forms a series of hydrides, the silanes. Silicon also forms a series of organic silicon compounds called silicones, when reacted with various organic compounds. 

Roewer G, Herzog U, Trommer K, Muller E, Friihauf S (2002) Silicon Carbide - A Survey of Synthetic Approaches, Properties and Applications 101 59-136 Rosa A, Ricciardi G, Gritsenko O, Baerends EJ (2004) Excitation Energies of Metal Complexes with Time-dependent Density Functional Theory 112 49-116 Rosokha SV, Kochi JK (2007) X-ray Structures and Electronic Spectra of the n-Halogen Complexes between Halogen Donors and Acceptors with jc-Receptors. 126 137-160 Rudolf P, see Golden MS (2004) 109 201-229... 

The Union Carbide team also utilized the dilithiocarborane chemistry to produce carboranylenesiloxane polymers by the metal-halogen interchange reaction (Fig. 4) between dilithiocarboranes and dichlorosiloxanes.21 Polymers with molecular weights up to 52,000 were synthesized by this procedure. 

See Other HALOGENATION INCIDENTS Metal acetylides and carbides... 

Binary rare-earth compounds such as carbides, sulfides, nitrides, and hydrides have been used to prepare anhydrous trihalides, but they offer no special advantage. Treating these compounds at a high temperature with a halogen (98) or hydrogen halide (115) produces the trihalide, e.g.,... 

Niobium pentaoxide undergoes two important types of reactions, one is reduction to niobium metal or to lower oxides, and the other involves conversion of pentoxide to oxide trihalides when treated with halogens or hahdes. These reactions occur mostly at elevated temperatures. Reductions may he carried out hy carhon, hydrogen, niobium carbide, niobium metal, and other reducing agents at elevated temperatures and often in vacuum ... 

Plutonium reacts with hydrogen at high temperatures forming hydrides. With nitrogen, it forms nitrides, and with halogens, various plutonium hahdes form. Halide products also are obtained with halogen acids. Reactions with carbon monoxide yields plutonium carbides, whde with carbon dioxide, the products are both carbides and oxides. Such reactions occur only at high temperatures. 

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