DC slice ion imaging of the ultraviolet photodissociation of 2-bromohexane

Abstract

The ultraviolet photodissociation dynamics of 2‑bromohexane around 234 nm has been investigated using the DC slice velocity map imaging technique. Relative quantum yield of the ground state bromine atom is measured to be 0.961. By analyzing the slice images, we can obtain the speed and angular distributions of the ground state and excited state bromine atoms. The speed distribution contains two Gaussian components, which are attributed to two dissociation channels. The high translational energy component is formed via the direct dissociation along the C–Br bond. Nevertheless, the low translational energy component is formed via the multidimensional dissociation along the C–Br bond coupling with the bending modes. The alkyl radical branching promotes the multidimensional dissociation. What’s more, the contribution of the electric-dipole allowed3Q1, 3Q0 and 1Q1 states to the product formation is also discussed. The nonadiabatic 1Q1←3Q0 transition plays a significant role in the dissociation process.