title: Vibrationally mediated photodissociation of CH3I [v1 = 1] at 277.5 nm: the vibrationally adiabatic process.
abstract: From the photofragment translational spectra of C-H symmetric stretch excited CH3I [v1 = 1, v2 = 0] photodissociatioin at 277.5 nm, the vibrational distribution of photofragments CH3 (v1 = 0, v2 = 0), (0,1), (1,0), (1,1) in the I* channel are measured to be 0.02, 0.02, 0.47, 0.25, and those of CH3 (1,0), (1,1) in the I channel are 0.04, 0.05, respectively. It shows that most of the dissociated CH3I [1,0] retain the C-H symmetric stretch vibration v1 = 1 in the photofragments CH3, and the vibrational distribution in umbrella bending mode is not seriously affected by the original C-H symmetric stretch excitation. The photodissociation of CH3I [1,0] mainly follows the vibrationally adiabatic process. The original vibrational excitation [v1 = 1] of CH3I is quite like a spectator, and the intramolecular vibrational-energy redistribution (IVR) does not play obvious part during photodissociation.
authors.affiliation: National Laboratory of Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China.
authors.forename: Lili
authors.initials: L
authors.lastname: Hu
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Zhou
authors.forename: Changwu
authors.initials: C
authors.lastname: Dong
authors.forename: Lijuan
authors.initials: L
authors.lastname: Zhang
authors.forename: Yikui
authors.initials: Y
authors.lastname: Du
authors.forename: Min
authors.initials: M
authors.lastname: Cheng
authors.forename: Qihe
authors.initials: Q
authors.lastname: Zhu