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'-X(2)A '' 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.