Recent advances in the syntheses and properties of polynitrogen pentazolate anion cyclo-N5− and its derivatives

摘要: The pentazolate anion, or cyclo-N5−, which is a five-membered ring composed solely of nitrogen atoms, has unique structure among polynitrogen compounds. Cyclo-N5− receiving ever-increasing levels attention because its potential ability to store large amounts energy compared the azide ion, environmentally friendly decomposition products, and carbon- hydrogen-free composition, are promising characteristics for advancing field high-energy-density materials (HEDMs), that include explosives, oxidisers, propellants in closed environments. In this review, we provide detailed introduction cyclo-N5− cover following topics: (1) substituted pentazoles as precursors with focus on syntheses stabilities pentazole derivatives; (2) routes through cleavage C–N bonds pentazoles, during competitive reactions between bond need be considered ensure successful outcome; (3) complexes summarising recent progress toward producing cyclo-N5−-based assembly isolated both metallic nonmetallic components; (4) interactions metal cations non-metal species, well factors influence stability these complexes; particular, thermal prepared salts discussed. This review summarises studies intended improve understanding chemistry while supporting further research into application an efficient, safe, HEDM.