The explosive RDX (1,3,5-trinitrohexahydro-s-triazine) is thought to decompose by homolytic N-N bond cleavage, among other possible initiation reactions. Quantum chemistry calculations show that the resulting aminyl radical can abstract an oxygen atom from a neighboring nitramine molecule, producing an aminoxyl (nitroxyl) radical and a nitrosamine. This O-transfer reaction is exothermic by about 50 kJ/mol [B3LYP/6-31G(d); estimated standard uncertainty = 22 kJ/mol for enthalpy changes]. Nitrosamines had previously been thought to result only from radical recombination. The aminoxyl radical derived from RDX can lead easily to the OST product (s-triazine N-oxide) observed mass spectrometrically by Behrens and coworkers. The formation of persistent aminoxyl radicals is consistent with autocatalytic red oils reported in the early literature.
Proceedings Title: Proceedings of 55th JANNAF Propulsion Meeting
Conference Dates: May 12-16, 2008
Conference Location: Newton, MA
Pub Type: Conferences
Aminoxyl, decomposition, nitramine, nitroxyl, quantum chemistry, RDX, reaction mechanism