Sodium hydride physical properties

Despite the fact that many boron hydride compounds possess unique chemical and physical properties, very few of these compounds have yet undergone significant commercial exploitation. This is largely owing to the extremely high cost of most boron hydride materials, which has discouraged development of all but the most exotic appHcations. Nevertheless, considerable commercial potential is foreseen for boron hydride materials if and when economical and rehable sources become available. Only the simplest of boron hydride compounds, most notably sodium tetrahydroborate, NajBHJ, diborane(6), B2H, and some of the borane adducts, eg, amine boranes, are now produced in significant commercial quantities. 

The compound sodium hydride, formed in reaction (29), is a crystalline compound with physical properties similar to those of sodium chloride. The chemical properties are very different, however. Whereas sodium burns readily in chlorine, it reacts with hydrogen only on heating to about 300°C. While sodium chloride is a stable substance that dissolves in water to form Na+(aqJ and CV(aq), the alkali hydrides bum in air and some of them ignite spontaneously. In contact with water, a vigorous reaction occurs, releasing hydrogen ... 

These findings did encourage us to examine further the biological properties of the imidazoisoindoles, particularly since their physical properties were also quite different from their phthalimide precursors. The first requirement was an improved procedure for the synthesis of the imidazoisoindoles. A number of reagents, both acidic and basic, were found that would effect cyclization of these phthalimides. One o the most consistent methods utilized sodium hydride in hot toluene or xylene. Some large-scale preparations, e.g. of were successfully run using sodium hydroxide pels in xylene. 

Physical properties of the alkali melal hydrides are given in Table I. Sodium hydride finds commercial usage in organic synthesis in condensation and alkylation reactions. 

Alkyl vinyl ethers (CH2=CH—OR R = ethyl or higher alkyl) are washed successively with 10% aqueous sodium hydroxide solution and deionized water and distilled at least twice over calcium hydride. The final cut is distributed into small brown ampoules under dry nitrogen and sealed immediately before being stored in a refrigerator. The following show some physical properties needed for experiments ... 

Treatment of J with sodium hydride in THF closed the azetidine ring smoothly to give K in 81% yield. Then, K was reduced with sodium naphthalenide to remove the tosyl group. Penaresidin A [(25,37 ,45,11 5,12 5)-156] was obtained after further deprotection of the TBS group. Peracetylation of 156 afforded the tetraacetyl derivative, whose specuoscopic and chiroptical properties were in accord with those of the tetraacetyl derivative of the natural product. Isomers of penaresidin A with (25,37 ,45,11 7 ,12 5)- and (25,35,45,11 5,12 7 )-configurations were also synthesized, but their physical properties were different from those of the natural penaresidin A. 

Sodium aluminate, 2 345t, 358-359 analysis, 2 275-276 economic aspects, 2 275 health and safety factors, 2 276 manufacture, 2 274-275 neutralization, 2 424 physical and chemical properties of, 2 273-274 uses of, 2 276-277 in water treatment, 26 111 Sodium aluminosilicate gels, synthetic zeolites prepared from, 16 831t Sodium aluminosilicates, 12 578 Sodium aluminum hydride, 13 621, 623-624... 

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