Collisional energy transfer in two-channel thermal unimolecular reaction of bromoethane-2-$d_1$

Abstract

PART A Iterative Solution of the Master Equation for Thermal Unimolecular Reaction by Variable Successive Overrelaxation Method A new algorithm called "Variable Successive Overrelaxation" (VSOR) method is suggested as an iterative solution of the master equation for thermal unimolecular reaction system. Considerable emphasis has been given to the convergence analysis of the VSOR method applied to the numerical solution of the VSOR method applied to the numerical solution of master equation. The convergence rate by the method is improved by at least six times over the well known technique of Tardy-Rabinovitch (TR) algorithm. Also, the prescaled master equation has led to give the mathematical proof on the sequential convergence for widely used TR method. The comparisonal study is performed for various iteration techniques on a well known system, i.e., the thermal isomerication of cyclopropane-1,1-$d_2$. PART B Collisional Energy Transfer in Two-Channel Thermal Unimolecular Reaction of Bromoethane-2-$d_1$ The unimolecular thermal decomposition in two-channel bromoethane-2-$d_1$ system was studied over the temperature range of 660-706 K in the presence of $CF_4$ and He bath gases. $C_2H_5Br$ system was also studied as a reference process. The average energy removed per collision from energized bromoethane-2-$d_1$ by a bath gas ( E)down are: by th substrate, 1100(stepladder model); by $CF_4$, 675(exponential model-EXP-); by He, 215 $cm^1$(EXP.). Comparison is made with recent studies of direct measurements. The relative rate ratio of two-channel reaction has been expressed in terms of microscopic rate ratio and distribution function of the reacting molecule. Arrhenius parameters, i.e., log A and $E_a$(kcal/mole), at ca. 50 torr of total pressure were found to be: for $C_2H_5Br$, 13.37$\pm$0.18, 53.36$\pm$0.55; for $CH_2DCH_2Br$, 13.16$\pm$0.16, 53.30$\pm$0.51 (HBr elimination) and 12.83$\pm$0.30, 54.29$\pm$0.92(DBr elimination).