Links between surface electrostatic potentials of energetic molecules, impact sensitivities and C–NO2/N–NO2 bond dissociation energies

Abstract

Earlier work has shown a link—not necessarily a causal relationship—between the impact sensitivities of energetic compounds and the electrostatic potentials on their molecular surfaces. The latter are anomalous in that the positive regions are strikingly dominant, contrary to what is typical of organic molecules. In this work, we show that the presence of several electron-withdrawing NO2 groups and/or aza nitrogens (common features of energetic systems), which is the reason for the anomalously positive surface potentials, also weakens the C–NO2 and/or N–NO2 bonds. Thus, insofar as these are trigger linkages, the rupture of which is a key step in detonation initiation, an approximate correlation between the features of the surface potentials and sensitivity may be expected. A group of eight nitramines is used to demonstrate this. Work is in progress to elucidate the basis for the surface potential–sensitivity link when a non-trigger-linkage mechanism is operative.