Early decomposition of hydroxylamine cations and thermal stability of dihydroxylammonium 5,5-bistetrazole-1,1-diolate

The presence of hydroxylamine anions enables typical high-energy ionic salt 5'-bistetrazole-1,1'-diolate (TKX-50) to form abundant hydrogen bonds, which can dissipate external energy stimuli through reversible hydrogen transfer between hydroxylamine cation and bistetrazole N-oxide anion. It has been theoretically demonstrated that the hydroxylamine cation in TKX-50 could be pre-decompose under thermal stimulation, however, the effect of a small amount of hydroxylamine cations decomposition on thermal stability of TKX-50 has not been reported yet. Herein, the influence of earlier decomposition of hydroxylamine cations on thermal stability of TKX-50 is systematically analyzed, which enhances the application prospects of TKX-50 and explains the promise of hydroxylamine cation as a common coordination ion of energetic ion salt. The results reveal that the decomposition of hydroxylamine cation in TKX-50 is extremely difficult under usual storage conditions. Despite the pre-decomposition of hydroxylamine cation, thermal stability and impact sensitivity of TKX-50 still meet the practical requirements.