Study on Dissociation Mechanism of Hexanitrohexaazaisowurtane (HNIW) Ion from Electron Impact

In order to understand the thermal behavior of hexanitrohexaazaisowurtane (HNIW), the dissociation mechanism of ions resourced from HNIW is studied in this paper. A ZAB-HS mass spectrometer with Mass Analyzed Ion Mikes Energy Spectrum (MIKES) is used to study various kinds of ions produced by electron impact for HNIW. There exist two basic pathways of the ionization and ionic cleavage reactions from HNIW by electron impact: One is initiated from an ionized nitro-group attached to a five-membered ring, another is initiated from an ionized nitro-group attached to a six-membered ring. In the cleavage reactions of HNIW-NO₂ ions, the production of NO₂ is attributed to "the effect of β-inducement", and the production of NO is attributed to "the effect of α-inducement". For framework HNIW ions without NO₂ group, HCN molecule is produced through alpha;-cleavage and i-cleavage reactions in the framework. Moreover, when HCN is removed, cyclization or "inducement rearrangement of adjacent radical" usually occurs.