In this structure, there are four N-H bonds in the ring and four C-H bonds at the end of the ring which can be replaced by additional functional groups such as nitro, isocyano, azido functional groups and so on. On the other hand, five-membered nitrogen-rich heterocycles are potential candidates for traditional energetic materials. Research also reported that -C=C- group is more stable than -C=O or -N=N-group and thus, a new patent structure C 6H 10N 4 ( Figure 1, C) was designed. Because there are four nitro groups in the molecule which will improve the heat of formation, while the carbonyl groups located at the end of the molecule makes it decompose easily under moisture. Take TNGU for example, it is moisture sensitive though its detonation performances are superior to those of RDX and HMX. However, in most cases, the requirements of high detonation velocity and detonation pressure are often contradictory to their physical properties such as thermal and hydrolytic stability, sensitivity toward heat, shock, friction and electrostatic discharge, positive oxygen balance, environmentally benign decomposition products, low cost and so on. etc., they are all HEDMs with high positive heats of formation (HOFs) and superior detonation performances ( D, detonation velocity and P, detonation pressure). and 1,3,5,7-tetranitro-1,3,5,7-tetraazacyclooctane (HMX) 7 7 Landenberger, H.

For instance, from the original well-known explosives 1,3,4,6-tetranitroglycouril (TNGU, Figure 1, A), 5 5 Pagoria, P.

Therefore, the design and synthesis of new HEDMs with high performance properties has been one of the most challenging tasks in this field. Poly-nitro compounds continue to attract considerable interest for their wide applications in propellants, explosives and pyrotechnics.

Based on the high positive heat of formation (HOF, 740.4 kJ mol -1), excellent detonation properties (detonation velocity D, 9.77 km s в€’1 detonation pressure P, 45.9 GPa), energy gap (О” E LUMO-HOMO) 4.19 eV and the molecular electrostatic potentials (MEP), it is predicted that 3,7-bis(dinitromethylene)-2,4,6,8-tetranitro-2,4,6,8-tetraazabicyclo octane could be may be a superior high-energy density compound (HEDC) to RDX and HMX.Дensity functional theory heat of formation energetic properties electronic structure crystal structure The calculated results show that this compound has a centrosymmetric structure and the molecular packing prediction indicates that the crystalline packing of the title compound is P2 12 12 1 and the corresponding cell parameters are as follows: Z=4, a= 22.03 Г…, b=8.73 Г…, c=8.42 Г…, бЋ±=90В°, ОІ=90В° and Оі=90В°. The IR spectrum, crystal structure, electronic structure, thermodynamic properties, heat of formation and detonation properties of a new polynitro heterocyclic energetic material 3,7-bis(dinitromethylene)-2,4,6,8-tetranitro-2,4,6,8-tetraazabicyclooctane were investigated theoretically.

Materials studio heat of formation