Trinitroazetidine by Photofragmentation Translational Spectroscopy

Studies of Initial Dissociation Processes in 1,3,3-Trinitroazetidine by Photofragmentation Translational Spectroscopy Deon S. Anex, John C. Allman, and Yuan T. Lee 

The method discussed here is photofragmentation translational spectroscopy. In this method, the molecule of interest is expanded frcMn a nozzle into a vacuum, and then the expansion is collimated to form a molecular beam. The molecular beam is then crossed with the output of a pulsed CO2 laser which excites the molecule of interest above the dissoda-tion threshold, relying on infrared multiphoton excitation to induce decomposition. In order to dissociate, a molecule must absorb approximately 20 infrared photons. 

The techniques used in these experiments have several features tant for the study of the decomposition of energetic materials. First, the excitation step using the CO2 laser infrared multiphoton absorption provides a way of heating the molecule under isolated conditions. After an initial coherent multiphoton absorption step, the infrared photons are sequentially absorbed, proceeding through the high density of states legton 

Second, the molecules dissodate under collision-free conditions. This precludes the possibility of secondary bimolecular reactions. Additionally, the fragments travel undisturbed to the detector so their velocities reflect the energy released into translation during the reaction. 

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