Collisional Energy Transfer in the Two-Channel Thermal Unimolecular Reaction of Bromoethane-2-d

Article abstract of DOI:10.1021/j100293a031

Unimolecular thermal decomposition in the two-channel bromoethane-2-d system was studied over the temperature range of 660-706 K in the presence of CF4 and He bath gases.The C2H5Br system was also studied as a reference process.The average energy removed per collision from energized bromoethane-2-d by a bath gas <ΔE>_down is as follows: by the substrate, 1100 cm^-1 (stepladder model); by CF4, 675 cm^-1 (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/mol), at ca. 50 Torr of total pressure were found to be as follows: for C2H5Br, 13.37 +/- 0.18, 53.36 +/- 0.55; for CH2DCH2Br, 13.16 +/- 0.16 and 53.30 +/- 0.51 (HBr elimination) and 12.83 +/- 0.30 and 54.29 +/- 0.92 (DBr elimination).