Posts Tagged ‘Ammonia borane’

Hydrogen capture by boron: a crazy reaction path!

Thursday, September 21st, 2017

A recent article reports, amongst other topics, a computationally modelled reaction involving the capture of molecular hydrogen using a substituted borane (X=N, Y=C).[cite]10.1073/pnas.1709586114[/cite] The mechanism involves an initial equilibrium between React and Int1, followed by capture of the hydrogen by Int1 to form a 5-coordinate borane intermediate (Int2 below, as per Figure 11). This was followed by assistance from a proximate basic nitrogen to complete the hydrogen capture via a TS involving H-H cleavage. The forward free energy barrier to capture was ~11 kcal/mol and ~4 kcal/mol in the reverse direction (relative to the species labelled Int1), both suitably low for reversible hydrogen capture. Here I explore a simple variation to this fascinating reaction.

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