Combination of Polynitro-pyrazole and 5-amino-1,2,4-oxadiazole Derivatives: an Approach to High Performance Energetic Materials

A series of N-methylene-bridged polynitropyrazoles and 5-amino-1,2,4-oxadiazole derivatives were successfully synthesized. All these compounds were determined by single-crystal X-ray diffraction. Noteworthy, a special packing diagram similar to multiparallel ladder (or gene chains) is formed in compound 9 through numerous hydrogen bonding and p-p interactions. On the basis of crystal structure, the energy properties and stability of those compounds were further explored. Results show that thanks to the high density (rho(7) = 1.86 g cm(-3) and rho(8) = 1.84 g cm(-3)), positive heats of formation (Delta H-f(7) = 1090.7 kJ mol(-1) and Delta H-f(8) = 480.3 kJ mol(-1)), and good oxygen balance (OB7 = 0 and OB8 = +6.96%) of compounds 7 and 8, they exhibit excellent detonation performance (D-v = 8897 and 9014 m s(-1), P = 35.2 and 36.7 GPa, respectively), which are comparable to the high explosive, such as RDX and HMX.