Hydrides of magnesium

J.-M. Welter, P.S. Rudman, Iron catalyzed hydriding of magnesium , Scripta Metall. 16 (1982) 285-286. 

Inelastic neutron scattering (INS) measurements on hydrides of magnesium and its compounds... 

The hydrides of beryllium and magnesium are both largely covalent, magnesium hydride having a rutile (p. 36) structure, while beryllium hydride forms an electron-deficient chain structure. The bonding in these metal hydrides is not simple and requires an explanation which goes beyond the scope of this book. 

Write a balanced chemical equation for (a) the reaction between sodium hydride and water (b) the formation of synthesis gas (c) the hydrogenation of ethene, H,C= GH2, and give the oxidation number of the carbon atoms in the reactant and product (d) the reaction of magnesium with hydrochloric acid. 

Reaction of an alkyl (usually trimethyl) of Group-IIIb element (Al, Ga, In) with a hydride of a Group-Vb element (P, As, Sb) at 600-800°C and 1 atm. [4i][42] p. doping obtained from addition of diethyl zinc or bis(cyclopentadienyl) magnesium. 

Of several mixed hydrides, the magnesium-nickel hydrides were the most hazardous in terms of dust explosions. 

As we shall see later, borides (as well as oxides, nitrides, carbides, etc.) react with water to produce a hydrogen compound of the nonmetal. Thus, the reaction of magnesium boride with water might be expected to produce BH3, borane, but instead the product is B2ff6, diborane (m.p. -165.5 °C, b.p. -92.5 °C). This interesting covalent hydride has the structure... 

Scheme 16 summarizes the results obtained by enantioselective radical reduction of a-bromoester by chiral binaphthyl-derived tin hydride. The reactions were generally performed at - 78 °C. An increase in the temperature resulted in the lowering of the selectivity. All reactions mediated by (S)-configured chiral tin hydride showed an (R)-selective preference in the product. The use of the opposite enantiomer of the chiral stannane resulted in a quantitative reversal of the selectivity (not shown). The selectivity remained modest on addition of magnesium Lewis acids. These reductions were also feasible when a catalytic amount of chiral tin hydride (1 mol %) was employed in combination with an excess of achiral hydride NaCNBH3, providing similar results. 

Of the 313 samples examined, the dust explosion hazards of finely divided aluminium, aluminium-magnesium alloys, magnesium, thorium, titanium and uranium, and the hydrides of thorium and uranium, are rated highest [1]. The... 

Intimate mixtures of chlorates, bromates or iodates of barium, cadmium, calcium, magnesium, potassium, sodium or zinc, with finely divided aluminium, arsenic, copper carbon, phosphorus, sulfur hydrides of alkali- and alkaline earth-metals sulfides of antimony, arsenic, copper or tin metal cyanides, thiocyanates or impure manganese dioxide may react violently or explosively, either spontaneously (especially in presence of moisture) or on initiation by heat, friction, impact, sparks or addition of sulfuric acid [1], Mixtures of sodium or potassium chlorate with sulfur or phosphorus are rated as being exceptionally dangerous on frictional initiation. 

This hydride is decomposed with water, with the production of magnesium hydrate and hydrogen —... 

Formation of magnesium and calcium hydride compounds was first recognized by German chemists yet at the end of nineteenth century [95] but it took more than a half a century before a substantial yield of Mg hydride was obtained from direct... 

E. Wiberg, H. Goeltzer, R. Bauer, Z. Naturforsch, B. Teil 6 (1951) 394 cited after B. Bogdanovic, S-T. Liao, M. Schwickardi, P. Sikorsky, B. Spliethoff, Catalytic synthesis of magnesium hydride under mild conditions, Angew. Chem. Int. Ed. Engl. 19(10) (1980) 818-819. 

B. Vigeholm, J. Kj0Uer, B. Larsen, A.S. Pedersen, Formation and decomposition of magnesium hydride, J. Less-Comm. Metals 89 (1983) 135-144. 

C.M. Slander, Kinetics of decomposition of magnesium hydride, J. Inorg. Nucl. Chem. 39 (1977) 221-223. 

A. Yonkeu, I.P. Swainson, J. Dufour, J. Huot, Kinetic investigation of the catalytic effect of a body centered cubic-aUoy TiV, Mn, (BCC) on hydriding/dehydriding properties of magnesium, J. Alloys Compd. 460 (2008) 559-564. 

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