Bipentazole (N<sub>10</sub>): A Low-Energy Molecular Nitrogen Allotrope with High Intrinsic Stability
Sergey V. Bondarchuk
Abstract
In this Letter, we report a crystal structure prediction and characterization of a molecular nitrogen allotrope N10 (bipentazole) using state-of-the-art computational methods. To date, in the form of a P21 space group crystal, this allotrope is the most stable predicted form of nitrogen, other than N2, in the pressure range 0–42 GPa. Its metastability at ambient conditions was justified using phonon dispersion and mechanical properties calculations as well as ab initio molecular dynamics simulations. Due to a high intrinsic stability caused by aromaticity, bipentazole may appear to be the first nitrogen allotrope stable enough for a large-scale synthesis at ambient conditions. The calculations of propulsive characteristics revealed that bipentazole is an excellent “green” energetic material. A potential strategy for the synthesis of this compound is offered and rationalized. The unique electronic structure of bipentazole makes it a strongly electrophilic all-nitrogen reagent, which can exhibit unusual chemistry.