title: Thermally stable 3,6-dinitropyrazolo[4,3-c]pyrazole-based energetic materials.
abstract: 3,6-Dinitropyrazolo[4,3-c]pyrazole was prepared using an efficient modified process. With selected cations, ten nitrogen-rich energetic salts and three metal salts were synthesized in high yield based on the 3,6-dinitropyrazolo[4,3-c]pyrazolate anion. These compounds were fully characterized by IR and multinuclear NMR spectroscopies, as well as elemental analyses. The structures of the neutral compounds 4 and its salt 16 were confirmed by single-crystal X-ray diffraction showing extensive hydrogen-bonding interactions. The neutral pyrazole precursor and its salts are remarkably thermally stable. Based on the calculated heats of formation and measured densities, detonation pressures (22.5-35.4 GPa) and velocities (7948-9005 m s(-1)) were determined, and they compare favorably with those of TNT and RDX. Their impact and friction sensitivities range from 12 to >40 J and 80 to 360 N, respectively. These properties make them competitive as insensitive and thermally stable high-energy density materials.
authors.affiliation: Department of Chemistry, University of Idaho, Moscow, ID 838344-2343 (USA), Fax: (+1) 208-885-9146.
authors.forename: Jiaheng
authors.initials: J
authors.lastname: Zhang
authors.forename: Damon A
authors.initials: DA
authors.lastname: Parrish
authors.forename: Jean'ne M
authors.initials: JM
authors.lastname: Shreeve
keywords: bond dissociation enthalpy; energetic properties; explosives; fused heterocycles; thermal stability