Electronegativity at the Shock Front

In this work, a scale for pressure-adapted atomic electronegativity is used to make general predictions of bond polarity in H-, C-, N- and O-based compounds experiencing shock conditions. The qualitative picture that emerges is one of increasing polarity of several bonds common in energetic materials. The general predictions made are compared to, and found to support, claims of ionic decomposition routes in compressed nitromethane and nitrate esters at high pressure. Changing electronegativity is also suggested as a factor driving the ionic disproportionation of various molecular phases with compression. Calculations using the eXtreme-Polarizable Continuum Model (XP-PCM) predict increasing energy differences between ground and excited states in non-bonded H, C, N, and O atoms as a function of pressure. This data enables for a discussion on the reliability of electronegativity-based rationales at more extreme thermodynamic conditions.

Automated summary

This study uses a scale for pressure-adapted atomic electronegativity to predict bond polarity in compounds experiencing shock conditions, finding that bond polarity generally increases in energetic materials. The study also suggests that changing electronegativity plays a role in the ion disproportionation of molecular phases with compression.