Photodissociation dynamics of CH2BrCl at 234 nm Original Research Article

The photodissociation dynamics of CH2BrCl has been studied at 234 nm utilizing the molecular beam-imaging system. In the photolysis, the C–Br bond fission is observed exclusively. The internal energy of the Br(2P3/2) channel consists of two parts which is caused by the interaction between σ*(C–Br) and σ*(C–Cl) surfaces. This separation is newly resolved and studied to unravel the effect of another chromophore. The energy separation of two peaks is 25 kJ mol−1 and the ratio of fast to slow one is 3.2. The fast part is interpreted in terms of a rigid impulsive model with no vibrational excitation and the slow part by a soft one with a little vibrational excitation, respectively. The energy gap is suggested to be due to an umbrella motion.