Collisional energy transfer in two-channel thermal unimolecular reaction of chliroethane-1,1,$2-d_3$

Abstract

The unimolecular thermal decomposition in two-channel chloro-ethane-1,1,2-d$_3$ system was studied over the temperature range of 656.2-733.2 K. The experiments were carried out both in the neat system and in the presence of He and CF$_4$ as collision partners. Chloroethane system was also studied as a reference process. The values of $<\Delta{E}>_{down}$, average energy removed per collision from energized chloroethane-1,1,2-d$_3$ by collision partners, were obtained at 703.2K: by the substrate, 1000cm$^{-1}$ (stepladder model-SL-);by CF4, 600cm$^{-1}$(exponential model-EXP-);by He, 450cm$^{-1}$(EXP) and at 683.2K and 733.2 K:by the substrate, 1050cm$^{-1}$(SL) and 950cm$^{-1}$(SL), respectively. Arrhenius parameters for these reactions were found to be:log A=12. 95 and E$_a$=54.20kcal/mol for chloroethane system and log A=12.65 and E$_a$=55.09kcal/mol(HCl elimination);log A=13.16 and E$_a$=58.37kcal/mol(DCl elimination) for chloroethane-1,1,2-d$_3$ system.