Initial decomposition step and bimolecular hydrogen transfer of 3 3′-diamino-4, 4′-azoxyfurazan under high pressure and high temperature

3, 3'-diamino-4, 4'-azoxyfurazan (DAAF) is a promising energetic furazan compound. Few works about its chemical and physical properties under high pressure and high temperature are reported so far. Here the thermal decompositions of DAAF under high temperature and/or high pressure with neon gas or liquid water were studied using Raman spectra. Under high temperature and ambient pressure, the decomposition sequence of DAAF begins with the unimolecular homolysis of C-N-azoxy and further followed by the cleavage of N-H in NH2 group and the rupture of furazan ring. Application of high pressure induces the different initial decomposition process accompanied the variation of the intermolecular and intramolecular interactions. The initial step of DAAF is the breakdown of N-H at 473 K and 0.9 GPa, which facilitates the bimolecular hydrogen transfer from NH2 group to O-azoxy-N and finally induces the dissociation of the O from azoxy group. It results in the formation of DAAzF at 483 K when using neon as pressure transmitting medium. Moreover, big and fine rod-like DAAzF crystals are formed above 493 K at 0.8 GPa employing water as pressure transmitting medium. The existence of super high temperature water leads to the bimolecular hydrogen transfer and dissociation of O-azoxy from DAAF more easily for the interaction of O-azoxy center dot center dot center dot H and more DAAF crystals transformation into DAA(z)F. (C) 2022 The Combustion Institute. Published by Elsevier Inc. All rights reserved.

Automated summary

This study investigates the thermal decomposition of 3, 3'-diamino-4, 4'-azoxyfurazan (DAAF) under high temperature and/or high pressure conditions using neon gas or liquid water. The results reveal the decomposition mechanism and product formation of DAAF under different conditions. High pressure and high temperature influence the initial decomposition process of DAAF and the intermolecular/intramolecular interactions, leading to different reaction pathways and product formations. These findings are significant for further exploration and application of DAAF.