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

Abstract

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 CNazoxy and further followed by the cleavage of NH 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 NH at 473 K and 0.9 GPa, which facilitates the bimolecular hydrogen transfer from NH2 group to Oazoxy-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 Oazoxy from DAAF more easily for the interaction of Oazoxy…H and more DAAF crystals transformation into DAAzF.