Hydride halides

This section deals with the binary compounds that nitrogen forms with metals, and then describes the extensive chemistry of the hydrides, halides, pseudohalides, oxides and oxoacids of the element. The chemistry of P-N compounds is deferred until Chapter 12 (p. 531) and S-N... 

Numerous compounds adopt the PbFCl structure. These include, apart from fluoride chlorides, oxide halides MOX (M = Bi, lanthanoids, actinoids X = Cl, Br, I), hydride halides like CaHCl and many compounds with metallic properties like ZrSiS or NbSiAs. 

The oxides, hydrides, halides, sulphides, sulphate , carbonates, nitrates, and phosphates are considered with the basic elements the other compounds are taken in connection with the aoidio element. The double or complex salts in connection with a given element include those associated with elements previously discussed. The carbides, silicides, titanides, phosphides, arsenides, etc., are considered in connection with carbon, silicon, titanium, etc. The intermetallic compounds of a given element include those associated with elements previously considered. 

Metalloids Intermediate. Altered by dopants (semiconductors) No (brittle) Varies Varies (oxides). Low (hydrides, halides)... 

In the foregoing discussion there has been no intention of minimizing the importance or the scientific interest of the remaining types of volatile covalent compounds of silicon, such as the silylamines.41 Emphasis has been placed on the hydrides, halides, and esters, only because they are more important to the present methods for preparing the organosilicon products described in later chapters. 

A mixed indium hydride halide complex, (l) InH2Cl (29) has been prepared from the 1 1 reaction of [InH2Cl(NMe3) ] with carbene (1) (R = Mes, R = H), as shown in Scheme iP The structure of (29) is monomeric with the geometry at the In center close to tetrahedral. The In-C distance (2.244(6) A) is similar to those observed in (28) (2.200(7) A) and (25) (2.253(5) A). A related mixed gallium hydride iodide complex (1) GaH2l (30) has been isolated from the reaction of (26) with GaT, with concomitant deposition of galhum metal. Complex (30) is isostructural with the related indium complex (29) and has a Ga-C bond distance of 2.022(4) A. 

Hydrogen halides add to Ge(II) hydrides, halides, oxides or sulfides ... 

A combination mechanism (III) in which propylene is formed from the radical (Reactions 9-10), but propane is formed by hydride-halide exchange (Reaction 13) is also possible. 

The reaction of organic halides with hydrido complex is less readily analyzed than the reaction with pentacyanocobaltate(II) since the two complex species are in equilibrium in a hydrogen atmosphere (Reaction 1). The question of whether alkanes are formed via hydride reduction of a radical (Reaction 11, Mechanism I) or via hydride-halide exchange (Reaction 13, Mechanism III) must be determined indirectly. 

The reactions are commonly initiated with AIBN at ca. 80 °C in a solvent such as benzene or toluene, but alkyl halides have also been reduced at -60 °C with tributyltin hydride under sonication conditions.133-134 Some reductions of halides have been carried out by generating the tin hydride in situ from a molar equivalent of the reducing agent [lithium aluminium hydride, sodium borohydride, or poly(methylhydrosiloxane)] and a catalytic amount of organotin hydride, halide, or oxide. Reduction of halides has also been carried out under aqueous conditions, using 4,4 -azobis(4-cyanovaleric acid) (ACVA) as a water-soluble radical initiator.60... 

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