Bimolecular Reactions and Energy-Transfer Processes of Highly Vibrationally Excited Molecules Related to Energetic Materials

摘要

Infrared Multiphoton Absorption (IRMPA) was used to produce populations of vibrationally excited 1,1,2-trifluoroethane, which were characterized by optoacoustic measurements of absorbed laser power and collision free decomposition yields. The measurements were accurately fitted with a Master Equation that included Quack's theory of IRMPA, three RRKM unimolecular reaction channels, and collisional energy transfer. The highly constrained adjustable parameters indicate that the optical coupling matrix elements are dramatically reduced in magnitude near reaction threshold energies where vibrational anharmonicity becomes important. Observed infrared fluorescence from the excited molecules is in excellent agreement with Master Equation predictions and it was used to monitor collisional deactivation of the excited molecules. The energy transfer exhibits a weak vibrational energy on bimolecular reactions of TFE, but no such effects have yet been observed. A Monte Carlo method is described for efficient multidimensional integration not restricted to hyper-dimensional rectangles, but applied to more complicated domains. When known, the boundaries of a arbitrary integration region can be used to define the sampling domain, resulting in sampling with unit efficiency.