Ultrafast dynamics of cationic electronic states of vinyl bromide by strong-field ionization-photofragmentation

Strong field ionization-photofragmentation (SFI-PF) with ultrafast pump-probe scheme is a powerful approach to study the dynamics of molecular cationic electronic states. Here we carry out a SFI-PF study on the cationic electronic states of vinyl bromide, C₂H₃Br. The yields of the parent C₂H₃Br⁺ and the formation of the fragment (Br⁺, C₂H₂⁺ and C₂H₃⁺) ions have been measured at different pump-probe delay time. Analysis provides experimental evidence of A²A'-X²A" internal conversion of vinyl bromide cations which occurs in a time of about 220 fs, and the time of C₂H₃⁺ formation induced by the dissociation of the A²A' state around 300 fs. The study would add our knowledge of the behavior of electronic excited states of complex molecular cations.