Infrared absorption of explosive molecule vapors

Infrared absorption spectra have been obtained for the high explosive molecules TNT, RDX, and PETN in the vapor phase. Integrated band strengths were measured for the symmetric and antisymmetric -NO2 vibrations in each of these molecules. Ab initio calculations of vibrational frequencies and intensities were carried out for comparison with the experimental data. Previous measurements of the heats of vaporization of these materials were checked using the temperature dependence of infrared band intensities. Measurements were also carried out on ammonium nitrate; in this case, only the decomposition products NH3, HNO3, and N2O were observed in the vapor phase in equilibrium with the solid. (C) 1997 Elsevier Science B.V.