Molecular modification of known explosives is considered to be an efficient route to design new energetic materials. A new family of energetic salts based on the 3,5-bis(dinitromethyl)-1,2,4-triazole monoanion and dianion were controllably synthesized by using 1-diamino-2,2-dinitroethene as a precursor. X-ray structure determination of monohydrazinium 3,5-bis(dinitromethyl)-1,2,4-triazolate (5) and monoammonium (6) and diammonium 3,5-bis(dinitromethyl)-1,2,4-triazolate hydrate (8·H2O) further confirmed the structures of these anions. In addition, as supported by X-ray data, in the monoanion system, the roving proton on the ring nitrogen rather than on the gem-dinitro carbon results in extensive hydrogen-bonding interactions and higher packing coefficients. Interestingly, 5 and 6 possess the highest calculated crystal densities, 1.965 and 1.957 g cm-3 at 150 K, for hydrazinium and ammonium energetic salts, respectively. Energetic evaluation indicates that 5 (detonation velocity vD = 9086 m s-1 detonation pressure P = 38.7 GPa) and 6 (vD, 9271 m s-1 P = 41.0 GPa) exhibit great detonation properties, superior to those of current highly explosive benchmarks, such as 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) and octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX).
Bibliographical noteFunding Information:
Financial support of the Office of Naval Research (NOOO14-16-1-2089), the Defense Threat Reduction Agency (HDTRA 1-15-1-0028), and CFD Research Corporation are gratefully acknowledged.
© 2016 American Chemical Society.
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