A dynamic prediction of stability for nitromethane in external electric field

Abstract

Adding an external electric field into an energetic material system can increase the energy but the stability may be reduced. In this paper, the effects of external electric fields on the initiation reaction dynamics of CH₃NO₂ (intermolecular and 1,3-intramolecular hydrogen transferences) were investigated using the MP2/6-311++G(2d,p) and CCSD/6-311++G(2d,p) methods. The results show that, when the external electric field is in the −y-direction of the CH₃NO₂ dimer (perpendicular to the O⋯N⋯N plane), the barriers of intermolecular hydrogen transference are lower than the C–NO₂ bond dissociation energies, leading to a preference for the hydrogen transference path over the C–NO₂ bond dissociation, and the sensitivities are higher than in the absence of an external electric field. However, in the other fields (except for the C–NO₂ bond axis direction with a field strength larger than +0.0060 a.u.), the C–NO₂ bond scission is favored and the sensitivities are almost equal to those in the absence of an external electric field. Although due to many obstacles, at present the proposition of adjusting the explosive sensitivity with external electric field does not make any sense in practice, the external-electric-field effect on explosive sensitivity must arouse intense interest in future.