Photolysis of ethyl chloride at 121.6 nm

Abstract

The photolysis of ethyl chloride at 121.6nm was studied over the pressure range 0.5-30 Torr at room temperature using a hydrogen atom resonance lamp. Pressure effect was investigated with and without $SF_6$. A scavenger effect of the reaction was also observed by adding NO gas. The major products of the reaction were $CH_4$, $C_2H_4$, $C_2H_6$, and $C_2H_2$. The branching between the elimination process and radical process are 0.68 to 0.32. Collisional deactivation of vibrationally excited ethylene molecule from the photolysis was studied at pressure region with the presence of $CO_2$ and $SF_6$ as collisional partners. By observing the ratio of stabilization to decomposition(S/D) of ethylene, the comparision was made between the experimental result and the theoretical estimation. The RRKM calculation was used to analyze the experimental results quantitatively and the pressure dependence on product ratios was well explained by the calculation. The S/D of the theoretical estimation increased sharply with pressure, but that of experimental result slight increased with pressure. The discrepancy was well explained in terms of the competitive reaction to stabilization/decomposition of $C_2H_3Cl$ and energy distribution of hot ethylene.