Ammonia borane dehydrogenation

Chemical hydrogen storage-where hydrogen is stored in a chemical compound and released via a reversible chemical reaction-represents a promising strategy [36]. Ammonia borane (H3NBH3) and related aminoborane compounds have 

The result of theoretical investigations have suggested that cleavage of a B—H bond occurs to initiate ammonia borane dehydrogenation [38]. Alternatively, the oxidative N—H addition of ammonia to the dehydrogenated intermediate C may constitute a feasible reaction pathway due, in particular, to the fact that ammonia and aniline oxidative addition to la and related iridium-PCP systems has been reported experimentally [39]. 

1 (a) Morales-Morales, D. and Jensen, C. (eds) (2007) The Chemistry of Pincer Compounds, Elsevier, Amsterdam  

10 de Vries, J. and Elsevier, C.J. (eds) (2007) Handbook of Homogeneous Hydrogenation, Wiley-VCH Verlag GmbH, Weinheim. 

12 Kanzelberger, M., Singh, B., Czerw, M., Krogh-Jesper, K. and Goldman, A.S. (2000) Journal of the American Chemical Society, 122, 11017. 

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Pons V, Baker RT, Szymczak NK, Heldebrant DJ, Linehan JC, Matus MH, Grant DJ, Dixon DA (2008) Coordination of aminoborane, NH2BH2, dictates selectivity and extent of H-2 release in metal-catalysed ammonia borane dehydrogenation. Chem Commun 6597-6599... 

Bluhm, M. E. Bradley, M. G. Butterick, R. Kusari, U. Sneddon, L. G., Amineborane-based chemical hydrogen storage Enhanced ammonia borane dehydrogenation in ionic liquids, J. Am. Chem. Soc. 2006, 128, 7748-7749. 

Bluhm ME et al (2006) Amineborane-based chemical hydrogen storage enhanced ammonia borane dehydrogenation in ionic liquids. J Am Chem Soc 128 7748-7749 Chandra M, Xu Q (2007) Room temperature hydrogen generation from aqueous ammonia borane using noble metal nanoclusters as highly active catalysts. J Power Sources... 

Zhou, X., et ah, Deposition ofFe-Ni nanoparticles on polyethyleneimine-decoratedgraphene oxide and application in catalytic dehydrogenation of ammonia borane. Journal of Materials Chemistry, 2012. 22(27) p. 13506-13516. 

From a chemical point of view, the AB decomposition in solution may allow one to adjust the type of decomposition product obtained after dehydrogenation and thus may influence the recycling strategy to be applied. Furthermore, benefits from improved kinetics can also be expected. Of course, the fundamental prerequisite is a high solubility and the stability of ammonia borane in the solvent in question. Corresponding data are given in Section 8.2. 

Scheme 8.4 Proposed mechanism for the metal catalyzed dehydrogenation of ammonia borane.

Scheme 8.5 Proposed mechanism for the acid-initiated dehydrogenation of ammonia borane in solution.

When the same reaction was carried out with the nickel analogue, complete decomposition to compound 43, in which one of the NHC rings had opened, took place (Scheme 3.15). ° A similar migratory insertion of a ligand on nickel to the NHC was proposed by Hall et al. based on computational studies of the dehydrogenation of ammonia borane by NHC-Ni-NHC based catalysts. 

TRANSITION METAL(O) NANOPARTICLES AS CATALYST IN THE DEHYDROGENATION OF AMMONIA BORANE... 

TABLE 7.4 Transition Metal Nanoparticles Catalysts Employed in Dehydrogenation of Ammonia Borane the Activity of Catalyst in Turnover Frequency (TOF)... 

Keaton, R. J. Blacquiere, J. M. Baker, R. T., Base metal catalyzed dehydrogenation of ammonia-borane for chemical hydrogen storage, J. Am. Chem. Soc. 2007,129, 1844-1845. 

Control of Shell Thickness of Hollow Silica-Alumina Composite Spheres and their Activity for Hydrolytic Dehydrogenation of Ammonia Borane... 

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