Weak Interaction Network in N₂O₄/HNO₃/H₂O Corrosive Microenvironments: A Quantum Chemical Mapping

Quantum chemical mapping of weak interaction networks in N₂O₄/HNO₃/H₂O and HNO₃/N₂O₄ propellant systems is reported. Electrostatic potential analysis identifies HNO₃ as the dominant hydrogen bond donor (+64.28 kcal/mol), forming the strongest complex with H₂O (-9.45 kcal/mol). In the ternary HNO₃···N₂O₄···H₂O cluster, water acts as a polarization catalyst, inducing a cooperative stabilization of 1.99 kcal/mol by enhancing the HNO₃ donor ability. Most significantly, in water-depleted 2HNO₃···N₂O₄ clusters, a specific weak interaction topology prefigures a concerted double proton transfer pathway (ΔE‡ = +32.1 kcal/mol), forming [HNO₂···NO₂⁺]···NO₃^- ion pairs. This finding provides a new theoretical hypothesis for the source of ions beyond the dissociation of HNO₃ in future studies of corrosion origin. Solvation models further confirm the persistence of these weak interaction networks and the feasibility of the proposed proton transfer pathway in the liquid N₂O₄ environment.