Influence of charge states on the reaction mechanism of RDX (1,3,5-trinitro-1,3,5-triazine)

ABSTRACT Understanding the initiation and early reaction mechanisms of RDX is essential for evaluating its safety and tuning its sensitivity. Unlike thermal and impact loading, external stimuli such as laser irradiation, friction, and electrostatic accumulation can induce charge transfer, making charged states directly relevant to the earliest chemical responses of energetic materials. To clarify these effects, density functional theory (DFT) calculations were used to examine how electron gain and loss modify the structural characteristics and decomposition pathways of RDX. Transition states and energy barriers for representative channels, including N−NO 2 bond cleavage, HONO elimination, and C−N bond scission, were determined using CI-NEB. Successive HONO elimination remains the most favorable pathway across all charge states. Both positive and negative charging lower the barriers relative to the neutral molecule and suppress the concerted triple-ring fission. Positive charge preferentially promotes intramolecular H-atom transfer, whereas negative charge facilitates N−NO 2 and C−N bond cleavage. These findings provide molecular-level insight into how charge perturbations modulate RDX reactivity and offer a mechanistic basis for interpreting charge-related experimental observations.