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Title: Evaluation of the differential energy distribution of systems of non-thermally activated molecules

Thesis/Dissertation ·
OSTI ID:6807163

A non-thermally activated molecule may undergo pressure dependent deactivation or energy dependent decomposition. It should be possible to use the pressure dependent stabilization/decomposition yields to determine the energy distribution in non-thermal systems. The numerical technique of regularization has been applied to this chemical problem to evaluate this distribution. The resulting method has been tested with a number of simulated distributions and kinetic models. Application was then made to several real chemical systems to determine the energy distribution resulting from the primary excitation process. Testing showed the method to be quite effective in reproducing input distributions from simulated data in all test cases. The effect of experimental error proved to be negligible when the error-filled data were first smoothed with a parabolic spline. This method has been applied to three different hot atom activated systems. Application to /sup 18/F-for-F substituted CH/sub 3/CF/sub 3/ generated a broad distribution extending from 62 to 318 kcal/mol, with a median energy of 138 kcal/mol. The shape of this distribution (and those from the other applications) indicated the involvement of two mechanisms in the excitation process. Analysis of the T-for-H substituted CH/sub 3/CH/sub 2/F system showed a more narrow distribution (56-218 kcal/mol) with a median energy of 79.8 kcal/mol. The distribution of the T-for-H substituted CH/sub 3/CH/sub 2/Cl system, extending from 54.5 to 199 kcal/mol was seen to be quite similar. It was concluded that this method is a valid approach to evaluating differential energy distributions in non-thermal systems, specifically those activated by hot atom substitution.

Research Organization:
Texas A and M Univ., College Station (USA)
OSTI ID:
6807163
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English