Pushing the limits of the heat of detonation the construction of polynitro bipyrazole.

The trinitromethyl group is a highly oxidized group that is found as an active functionality in many high-energy-density materials. The most frequently used previous synthetic method for the introduction of the trinitromethyl group is the nitration of heterocyclic compounds containing an acetonyl/ethyl acetate/chloroxime group. Now a novel strategy for constructing a trinitromethyl group (5) nitration of an ethylene bridged compound, dipyrazolo[1,5-:5',1'-]pyrazine (2), is reported. In addition, the other two nitrated products (3 and 4) were obtained under different nitrating conditions. Compound 5 has excellent detonation performance ( = 9047 m s, = 35.6 GPa), and a low mechanical sensitivity ( = 10 J, = 216 N), with an especially attractive heat of detonation of 6921 kJ kg, which significantly exceeds that of the state-of-the-art explosive CL-20 (: 6162 kJ kg).