Computational Studies of FOX-7, A New Insensitive Explosive

摘要

First-principles quantum chemical calculations are used to predict the initial steps of decomposition in solid FOX-7 (1,1-diamino-2,2- dinitroethylene). Three possible reaction paths were studied: (1) intra- or inter-molecular hydrogen transfer; (2) nitro-nitrite rearrangement and (3) scission of the C-nitro bond. These computational studies suggest that the preferred path for FOX-7 decomposition will depend upon the conditions which cause initiation. For example, under gentle heating (thermolysis), intermolecular hydrogen transfer is likely, resulting in the production of reactive radical intermediates and water. Conversely, scission of a C-nitro bond requires a large energy input to cause electronic (singlet-to-triplet) excitation of the molecule, suggesting that this reaction is more likely to occur under the high-pressure/high-temperature conditions typically generated by shock or impact.