A theoretical study of the activation of nitromethane under applied electric fields

Abstract

C–N activation is the key step of nitromethane (NM) decomposition. The energy landscape of C–N rupture under applied electric fields with various directions and strengths were first studied by using CCSD and CCSD(T) calculations. When the field is applied in the C → N direction, the activation energy barrier (E_a) increases under a weak field, but decreases when the field is strong enough. When the field is applied in the C ← N direction, E_a decreases with the field strength. The E_a may vanish when the field is strong enough. The applied field perpendicular to the C–N bond has little effect on E_a. The reactivity of NM under the fields was analyzed with local softness, and the variation of E_a with the direction and strength of the applied field was rationalized with electron density change on the C–N bond driven by the field. Our studies provide useful information for the process, transportation and storage of energetic materials in presence of electric fields.