Searching for ways to create energetic materials based on polynitrogen compounds (review)

Abstract

Polynitrogen compounds (containing only nitrogen atoms) are promising candidates as energetic materials for rocket engineering. The high energy content of these compounds is due to the significant difference in bond energy between nitrogen atoms. In particular, molecular nitrogen (N 2 ) is characterized by a uniquely strong triple bond -229 kcal/mole, whereas the single-bond energy is only 38.4 kcal/mole. From theoretical estimates, use of polynitrogen compounds can provide a specific impulse of 350-500 sec with material density in a range of 2.0-3.9 g/cm 3 . This paper gives a brief review of the current status of experimental and theoretical studies in the chemistry of polynitrogen compounds.

From planes to cluster: The design of polynitrogen molecules

“…For conventional CAHANAO-based propellants or explosives, increasing the energy content becomes very difficult because their energy thresholds are approaching their limits of stability. Professor Dong [1] confirmed that the increase is not more than 30% in performance for CAHANAO-based explosives, and the upper limit of density is approximately 2.3 g/cm 3 .…”

“…As a result, some polynitrogen molecules were theoretically investigated in this article. A major motivation for this research is that polynitrogen molecules are expected to release a large amount of energy when they decompose into N 2 molecules . Therefore, these species are potentially promising as high‐energy‐density materials (HEDMs).…”

“…A major motivation for this research is that polynitrogen molecules are expected to release a large amount of energy when they decompose into N 2 molecules. [2][3][4] Therefore, these species are potentially promising as high-energy-density materials (HEDMs). Among the different energetic nitrogen compounds (nitrates, nitramines, azides, formazan, etc), [5] pure polynitrogen molecules are particularly attractive, due to the desired high-energy density and the sole product, N 2 , which is inert, eco-friendly, not a greenhouse gas.…”

N(4S /2D)+N2: Accurate ab initio-based DMBE potential energy surfaces and surface-hopping dynamics

“…The cyc-N 3 isomer, on the other hand, lies about 30 kcal mol −1 above this spin-forbidden limit and shows a large barrier to isomerization or dissociation, 34 which makes it a good candidate as a high energy density material. 12,13 For this reason, it has received considerable attention, and has been already detected experimentally, [6][7][8][9] but not isolated yet.…”

“…Although the linear one is widely known experimentally, 1-5 the ring form has only recently 6-11 been detected but its isolation remains elusive. As a nitrogen allotrope, it has potential applications as a high-energy density material, 12,13 and its natural tendency to dissociate to molecular nitrogen would make it a "clean" propellant.…”