Unlocking the potential of pyridazine: a promising backbone for high-energy density compounds

Abstract

Nitrogen-rich heterocycles represent a significant class of backbone in energetic compounds, distinguished by their substantial nitrogen content and elevated heats of formation. These characteristics make them a crucial area of investigation in the ongoing quest to develop high-energy-density materials (HEDMs). Within this domain, azines, which are heterocyclic compounds incorporating two or more nitrogen atoms within their ring structure, have garnered increasing scholarly interest. Inherent structural design of pyridazine facilitates the strategic integration of multiple explosophoric groups, thereby amplifying their energetic capabilities. Among the azine derivatives, pyridazines, a specific type of diazine, typically exhibit resistance to direct nitration. However, they can effectively undergo electrophilic substitution when activated by potent electron-donating functionalities. A notable characteristic of pyridazines is their planar molecular configuration, which promotes efficient π–π stacking interactions. This intermolecular arrangement contributes to highly dense crystal packing, consequently yielding materials with superior densities.