LAUSR

Abstract Density functional theory calculations were performed to provide an explicit physical understanding on how an external electric field affects molecular reactivity by taking energetic molecules nitromethane and triaminotrinitrobenzene as examples. The activation energies of C N cleavage, which is fixed to parallel or antiparallel to the applied field, in these molecules decrease when the bonds are either shortened or lengthened by the applied field. Our calculations reveal that the coupling of molecular dipole moment and/or polarizability with the applied field has a stabilization effect on the activated bond. Such effect increases during the C N bond cleavage, resulting in a lower activation energy than that in absence of the applied field. Moreover, the reduction in bond activation energy is favored in conjugated structures.