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Comparative Theoretical Investigation on Energetic Substituted Furazanyl Ethers

Liu N., Wang K., Shu Y., Zeman S., Wang B., Wang W.

Central European Journal of Energetic Materials

2018

Vol. 15, no. 1

47--71

Furazanyl ether has great potential to be an important candidate as a casting explosive and energetic plasticizer. The density functional theory (DFT) method was used to investigate the heats of formation (HOFs), molecular stability, detonation performance and melting point of a series of substituted furazanyl ethers at B3LYP/6-311G(d,p) level. The results show that the introduction of –N3 or –N(O)=N– groups significantly improves the HOFs values of the derivatives. The bond dissociation energies (BDEs) were analyzed, showing that the N–O bond in the furazan ring is the weakest for most compounds and the ring is vulnerable to cleavage in thermal decomposition. The calculation of density, detonation velocities and detonation pressures suggests that the substitution of –NF2, –CF(NO2)2, furoxan or –N(O)=N– group is an effective method for enhancing their detonation performance. The melting points were determined according to the variation of specific heat capacity, and good estimates were obtained in comparison with the available experimental data. Taking into account the detonation performance and melting point, four compounds are favoured for application in melt cast explosive or energetic plasticizers.

Nitro Groups vs. N-Oxide Linkages: Effects Upon Some Key Determinants of Detonation Performance

Politzer P., Murray J. S.

Central European Journal of Energetic Materials

2017

Vol. 14, no. 1

3--25

Increasing the nitrogen/carbon ratios in the molecular frameworks of C,H,N,O explosives has attracted considerable attention because it tends to result in more positive heats of formation and often greater densities. In conjunction with this, there has been a growing interest in N-oxide linkages, N+ → O−, as another source of oxygen in these compounds, in addition to or even possibly replacing NO2 groups. In this study, for a series of polyazines and polyazoles, we have compared the effects of introducing a single N-oxide linkage or NO2 group upon key properties that affect detonation velocity and detonation pressure. We found that: (1) The heats of formation per gram of compound, which is what is relevant for this purpose, are almost always higher for the N-oxides. (2) The nitro derivatives have greater densities and detonation heat releases. In relation to the latter, it must be kept in mind that increasing detonation heat release tends to be accompanied by increasing sensitivity. (3) The N-oxides produce more moles of gaseous detonation products per gram of compound.