Complex hydrides ammonia borane

Another effect is that confinement in pores might influence the phases formed for complex systems. Although not completely understood this is found experimentally, for instance, by Autrey ef al. for the confinement of ammonia borane in mesoporous Si02 and carbon (see Section 10.6.1) [74]. For complex materials often not only thermodynamic considerations but also kinetics have an import influence on which phases are formed upon hydriding or dehydriding. For instance, on decomposition of UBH4 the thermodynamically most favorable reaction is ... 

A. T-Raissi, "Ammonia and Ammonia-Borane Complexes as Hydrogen Energy Storers for Fuel Cell Applications," at Session A2.8 Hydrides II, 14th WHEC, Montreal, Canada, June 10 (2002). 

REDUCTION, REAGENTS Bis(triphenyl-phosphine)copper tetrahydroborate. Borane-Pyridine. Calcium-Methylamine/ ethylenediaminc. Chlorobis(cyclopenta-dienyl)tetrahydroboratozirconium(IV). Chromium(II)-Amine complexes. Copper(0)-lsonitrile complexes. 2,2-Dihydroxy-l, 1-binaphthyl-Lithium aluminum hydride. Di-iododimethylsilane. Diisobutyl-aluminum 2,6-di-/-butylphenoxide. Diisobutyl aluminum hydride. Dimethyl sulfide-Trifluoroacetic anhydride. Disodium tetracarbonylferrate. Lithium-Ammonia. Lithium-Ethylenediamine. Lithium bronze. Lithium aluminum hydride. Lithium triethylborohydride. Potassium-Graphite. 1,3-Propanedithiol. Pyridine-Sulfur trioxide complex. 

Sodium bis-(2-methoxyethoxy)aluminium hydride (ref. 84) and lithium tri-tert-butoxyaluminium hydride (ref. 85) showed excellent stereoselectivity for podophyllotoxin compared with other reagents. However, these reagents have the disadvantage that low temperature (-75 C) is required to obtain satisfactory yield. Although the stereoselectivity was inferior to that of the above-mentioned aluminium hydride complexes, borane-terf-butylamine complex (ref. 86) and borane ammonia complex (ref. 87) gave the products in more than 90% yield. The reactions proceeded at room temperature, and borane-tert-butylamine complex did not require the use of a nitrogen stream. 

Reviewed and evaluated more than 120 published papers, reports, patents and other archival records related to ammonia-based chemical hydrides, including amine borane complexes, as prospective chemical hydrogen storage compounds. 

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