Dehydrogenation of icosahedral carborane anions via gas-phase collisional activation.

Rationale: The icosahedral carborane anion HCB H is well known for its exceptional stability in solution and the solid state, but the gas-phase properties of this molecule have not previously been explored.

Methods: Electrospray ionization ion trap mass spectrometry, collisional activation, and isotopic labelling were used to examine the formation and reaction pathways of covalent and noncovalent carborane clusters.

Results: Covalent attachment of an amino group to the C-vertex of HCB H dramatically alters its stability in the gas phase. Interestingly, covalently bound carborane dimers are produced during electrospray ionization. Subsequent collisional activation of these dimers leads to facile hydrogen losses (7 H molecules). The loss of H does not follow a stochastic pattern, but occurs preferentially by loss of 3 H , followed by loss of 2 H and then another 2 H molecules.

Conclusions: This study provides insight into new possible modes of B-H activation and functionalization in carborane cages. Copyright © 2016 John Wiley & Sons, Ltd.