Kinetic studies of the pH dependence of the decomposition of 3,7-dinitro-1,3,5,7-tetra-azabicyclo[3.3.1]nonane (DPT) and related compounds
Kinetic studies are reported of the pH-dependence of the decomposition of 3,7-dinitro-1,3,5,7-tetraazabicyclo[3.3.1]nonane (DPT) in aqueous media. For comparison, data were also obtained for reaction of methylenedinitroamine (MDNA) and nitramide (NH2NO2) which are potential intermediates on the reaction pathway of DPT. Our results, while not providing a complete description of the decomposition of DPT, show that at all acidities two stages are observed. The first stage, k1, involves catalysis by protons and hydroxide ions and it is suggested that reaction occurs via a low-concentration, ring-opened structure which is in equilibrium with DPT. In acidic solution an intermediate, (A), is observed which is identified as nitramide while in basic solution a different intermediate (B) is formed. MDNA is shown not to be an intermediate in the DPT reaction since its rate of decomposition is too slow.