Theoretical Investigation of the Structural Characteristics of 2‐Dimethylaminoethylazide

ABSTRACT As a green liquid rocket propellant, 2‐dimethylaminoethylazide (DMAZ) is a promising alternative to hydrazine‐based fuels. However, its relatively long ignition delay significantly limits its practical application. The dynamics of the reaction between DMAZ and the oxidizer are likely to governed by their intrinsic structural characteristics. In this study, we conducted a comprehensive quantum chemical analysis to elucidate the critical structural features of DMAZ, including its spatial configuration, electronic structure, atomic charges, bond orders, and chemical reactivity. The optimized structure of DMAZ does not exhibit a linear conformation. The azide group is a key factor that distinguishes DMAZ from other N‐containing liquid propellants. Electronic structure analysis indicated that hyperconjugation within the DMAZ molecule enhanced its molecular stability which may be responsible for its extended ignition delay. Bond order analysis confirmed the characteristics of multicenter bonding in DMAZ, revealing that the bond order of N17‐N18 was greater than that of N16‐N17. Natural bond order analysis quantitatively validated the 3c–4e delocalized system comprised by delocalized ‐orbitals spanning all three atoms along the bond axis and localized ‐orbitals extending over the N17–N18 bond oriented perpendicular to the bond axis. Quantitative molecular surface analysis showed that N18 within azido group was the most favorable site for nucleophilic attacks, followed by N17. Conversely, N1 displays significant electrophilic behavior. These findings provide a systematic theoretical framework for understanding the molecular and structural characteristics of DMAZ.