Position Effect of Nitro Ring N‐Oxide Oxygen Proximity on the Initial Thermal Decomposition Pathways of Furoxan‐Based Energetic Materials

Reconciling high energy performance, low sensitivity, and high thermal stability remains a central challenge in the molecular design of energetic materials, as enhanced energy output is often accompanied by increased sensitivity and reduced thermal stability. Here, we systematically elucidate the microscopic mechanism by which the spatial position of nitro groups relative to ring N‐oxide oxygen governs initial decomposition pathways of furoxan‐based energetic materials. Using density functional theory (DFT) combined with transition‐state theory, we comparatively investigated two typical zero‐oxygen‐balanced structural analogues: 3,3′‐dinitro‐4,4′‐azo‐furoxan (DNAFO) and 4,4′‐dinitro‐3,3′‐dioxide‐furoxan (DNDFO). The calculated Gibbs free energy barriers reveal a distinct mechanistic bifurcation: in the ortho configuration, decomposition is predominantly initiated by C–NO 2 homolysis through a low Gibbs free energy difference of 9.2 kcal mol −1 , whereas in the non‐ortho configuration, cleavage of the ring N–O bond adjacent to the ring N‐oxide oxygen is favored, with a barrier of 20.3 kcal mol −1 . Electrostatic potential (ESP), atomic dipole moment corrected Hirshfeld (ADCH) charge, and Mayer bond order analyses indicate that this pathway switching originates from substituent‐induced charge redistribution, which selectively modulates the strength and reactivity of specific chemical bonds. For non‐ortho configured systems, the bridging architecture exerts a relatively limited influence on the intrinsic rate‐determining N–O cleavage barrier, suggesting that bridging motifs can instead be optimized with consideration of oxygen balance and crystal density. The established “position‐electronics‐reactivity” relationship provides microscopic insight into the structure‐dependent initial decomposition of furoxan derivatives and offers a theoretical basis for the rational design of energetic materials that balance energy release capability with enhanced thermal stability.