Molecular Dynamics in Nitramines and Modified Nitramines

The structure of RDX has been compared by the use of Fourier transform infrared spectroscopy in the gas phase, melt phase, solution phase, and the solid Beta and alpha phases. The gas, melt, and solid Beta-RDX phases have not been studied previously. The RDX molecule has essentially C sub 3V molecular structure in all environments except the stable solid Alpha-RDX phase. The RDX and HMX melts were found to be comprised almost entirely of intact nitramine molecules, but decomposition before melting was directly detected in HMX. RDX was found to be a highly flexible molecule. In keeping with this flexibility, the crystal structure of the complex between RDX and sulfolane revealed NN02 groups frozen in axial, equatorial, and planar positions within one molecule. The crystal structure of AZMTTC was determined and its thermal decomposition mechanism empirically reasoned. HN3, not previously recognized as a product, appears to trigger the decomposition of AZMTTC. Copious amounts of N20 and CH20 are then released due to depolymerization of the ring. The IR spectra of the gas and solid phases and the TGA all support this mechanism.