Hydride oxidation

Anhydrous HX are versatile and vigorous reagents for the halogenation of metals, non-metals, hydrides, oxides and many other classes of compound, though reactions that are thermodynamically permissible do not always occur in the absence of catalysts, thermal initiation or photolytic encouragement, because... 

Ge(OH)+, Ge(OH)2+, Ge(OH)3+ and Ge202+, etc. It is clear from these observations that atoms tends to form clusters in thin films. Thin films also tend to react with water in the atmosphere. In field evaporation, water molecules are desorbed in the form of hydride, oxide or hydroxide ions with the substrate atoms and atomic clusters. From the above discussions, it is clear that the FIM and atom-probe can now be applied to study a wide variety of problems for a wide variety of materials. Field ion microscopy is no longer confined to studying refractory metals, as many scientists still erroneously perceive. 

The hydrides, oxides and nitrides of the elements of the first three groups of the periodic system all behave as normal ionic compounds. They all show normal valencies, they crystallize in coordination lattices, do not show any metallic conductivity and, in so far as an estimate can be made of their heats of formation, they agree fairly well with the values to be expected for ionic compounds. 

The structures of the hydrides, oxides and nitrides in this group are rather peculiar, for they can always be described as lattices, as found in pure metals, with the negative ions inserted in the octahedral holes of these structures. In the case of TiN, TiO and, in general, all compounds AB, all octahedral holes are occupied, and the structure is that of the sodium chloride type. There are nitrides of other types, too, e.g. A2N, A3N, etc., in which cases only a part of the octahedral holes are occupied. 

Graedel TE. 1978. Inorganic elements, hydrides, oxides, and carbonates. In Chemical compounds in the atmosphere. New York, NY Academic Press, 35-49. 

The surface hydrides, surface oxides, and other surface compounds, mentioned above, need not be formed by the action of free atoms with free valencies on metal surfaces, but, just as in normal chemical reactions, these compounds may result from the reaction of the metal surfaces with molecules. The chemisorption of an H2 molecule on a metal surface may lead to the chemisorption of two separate hydrogen atoms and so may the action of an 02 molecule on a metal surface lead to the chemisorption of two oxygen atoms, the action of an N2 molecule to the chemisorption of two nitrogen atoms, etc. Surface hydrides, oxides, and nitrides are, then, the result of normal chemical reactions of these gases with the surfaces of the metals. 

The formation of surface hydrides, oxides, and nitrides is usually a result of the dissociative chemisorption of the molecules of these gases. As can be seen from Fig. 9, which gives the potential curves for such an adsorption, the heat of adsorption is given by the difference in energy level between A and E, this difference being given by... 

The second class includes the organolead derivatives of the various organic and inorganic acids, as well as the organolead hydrides, oxides,... 

A mechanism for catalysis by platinum compounds was proposed in 1965 by Chalk58) and has since been supported by increasing knowledge about silyl-metal systems and by the direct detection of Pt-Si211) and Rh-Si61,18s) complexes in the reaction mixtures. The suggested mechanism requires olefin coordination to the Pt(II) species (in the case of H2PtCl6 formed by reduction by the silicon hydride), oxidative addition of the silane, formation of an intermediate in which silicon and alkyl are both bonded to the platinum center, and reductive elimination of alkylsilane, probably assisted by coordination of more olefin ... 

Most borides are inert toward nonoxidizing acids, although Bc2B and MgB2 react with aqueous acids to form boron hydrides. Oxidizing acids such as nitric or hot sulfuric dissolve most borides. Hot aUcahne salt melts and fused alkali peroxides also dissolve borides to form the more stable borates. Borides are generally resistant to oxidation in dry air due to the formation of a protective oxide layer. Many borides do not oxidize in air below 1000 1400 °C. 

Table 3. Pseudo-aqueous pA"a data and metal-hydride oxidation potential data in THF or dichloromethane. ...

We have applied Eq. 29 to a series of Cp and Tp Group 6 metal carbonyl hydrides in acetonitrile, mostly on the basis of irreversible metal-hydride oxidation... 

Bokmi hydride oxide, ion (HBO ) Boron hydride oxide, ion (HBO ) Boron hydride sulfide (UBS)... 

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