Metal halides, halogenation with

Previous methodsfor the preparation of indium (I) bromide, as well as other indium monohalides and the dihalides, have utilized two main approaches. Either the metal was halogenated with free halogen or hydrogen halide under the appropriate conditions, or indium tri-... 

Figure 3-54. Equilibrium versus average structures of metal halide molecules with low-frequency, large-amplitude deformation vibrations (filled circles, metal open circles, halogen).

PbR4-type compounds usually are not sensitive to air, insoluble in water, and very stable to hydrolysis. However, prolonged contact with air causes slow degradation, especially in the presence of light. They react readily with halogens, hydrogen halides, nonmetal halides, a series of salts (mainly metal halides), and with aqueous solutions of strong acids. They are much less sensitive to bases. 

Anhydrous halides, however, are obtained when the metal is heated with the dry hydrogen halide or the halogen. In the case of elements with more than one oxidation state, the hydrogen halide produces a lower halide and the halogen a higher halide, for example... 

Many reactions of fluorinated organics with metal halides result in the replacement of fluorine with halogen A general route to 1,1,1-trichloro- or tribromo-fluoroalkanes involves treating primary fluoroalkyl iodides with aluminum trichloride or aluminum tribromide [74], Benzylic [75, 76] or vinylic [72] fluorine can be exchanged for chlorine when treated with aluminum trichloride... 

Metal halides can in some cases, be used to replace other atoms or groups besides fluorine with halogen Polyfluoroacyl fluorides and chlorides can be converted to fluoroalkyl iodides by simply heating the reactant in the presence of an alkali metal iodide [[Pg.382]

The X-ray photoelectron spectroscopy of metal halides and their complexes halogen binding energies and their correlation with structure. R. A. Walton, Coord. Chem. Rev., 1976,21, 63-91 (112). 

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. 

The activated nickel powder is easily prepared by stirring a 1 2.3 mixture of NiL and lithium metal under argon with a catalytic amount of naphthalene (1(7 mole % based on nickel halide) at room temperature for 12 h in DME. The resulting black slurry slowly settles after stirring is stopped and the solvent can be removed via cannula if desired. Washing with fresh DME will remove the naphthalene as well as most of the lithium salts. For most of the nickel chemistry described below, these substances did not affect the reactions and hence they were not removed. The activated nickel slurries were found to undergo oxidative addition with a wide variety of aryl, vinyl, and many alkyl carbon halogen bonds. 

Halomet [Halogen metal] A process for reducing halides to metals by reaction with metallic aluminum or magnesium in a closed vessel. Invented in 1968 by R. Nowak and W. Schuster at Halomet, Basle. 

Metallostannation often gives a better regio- and stereoselectivity than does hydrostannation, and the vinylmetal group that is formed can often react further with suitable electrophiles such as halogens, acids, alkyl halides, acyl halides, metal halides, aldehydes, or epoxides.110 ... 

Of the synthetic reactions of the alkyl halides that with potassium cyanide, which enabled H. Kolbe to synthesise acetic acid from a methane derivative, has already been mentioned (cf. the preparations on pp. 137 and 254). Of the simpler syntheses that of Wiirtz may be mentioned here. Metallic sodium removes the halogen from two molecules and the two radicles combine. Thus, in the simplest case, ethane is formed from methyl bromide ... 

PET can be made flame retardant (FR-PET) by halogenated additives in combination with synergists such as antimony compounds (which impart no flame inhibition by themselves). During combustion, volatile antimony trihalide is formed in the condensed phase and transported to the gas phase. Failure of this flame retardant in PET compounds can occur, however, due to the formation of stable metal halides such as the following ... 

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