Investigations Of Alkyl Bromides' Photodissociation Dynamics And Zero Kinetic Energy Spectroscopy

Photodissociation of alkyl bromides has been a popular area of investigation, in view of their ozone depletion potential and of the fundamental interest in photodissociation dynamics. Methyl bromides, in C_3v symmetry, have been extensively studied at their first absorption A-band because the behavior of these molecules can be used as a prototype for depicting numerous types of photodissociations in a variety of polyatomic molecules. In comparison with the methyl bromides, the photodissociation dynamics of alkyl bromides with a long C-C chain has not been studied in detail. There are few literatures reporting the photodissociation of these compounds at their A-band. In fact, the behavior of alkyl bromides with a long C-C chain, which belong to Cs symmetry, is more similar to that of general polyatomic molecules. So, in the present study, we have investigated the photodissociation of these alkyl bromides at their A-band using resonance-enhanced multiphoton ionization (REMPI) scheme, ion velocity map imaging technique, expecting to get a variety of information. Also, we have obtained the mass analyzed threshold ionization (MATI) spectra of ethyl bromide with one-color two-photon ionization via a dissociative intermediate state scheme, and analyzed the relationship between the vibrational structure and the dissociative intermediate state. The primary research works are summarized as follows: (1) Using resonance-enhanced multiphoton ionization (REMPI) scheme, we investigated the photodissociation of some alkyl bromides (C₂H₅Br, n-C₃H₇Br, n-C₇H₁₅Br,) and bromobenzene (C₆H₅Br) near 234nm and 267 nm. The branching ratios N(Br^*)/N(Br) of the compounds at two wavelengths were measured, and the ab...