Ultrafast Hydrogen Migration and Fragmentation Dynamics in 1- and 2-Propanol *

We present a comparative study of laser-induced fragmentation and hydrogen migration dynamics, triggered through ionization, for the two structural isomers, 1-propanol and 2-propanol. Using pump-probe spectroscopy in combination with coincident ion-momentum imaging techniques, we identify the channels showing direct breakup and single/double hydrogen migration for both the isomers. We extract the kinetic energy release (KER) as a function of pump-probe delay, which helps determine the timescales of the different processes. Interestingly, we observe different features in the KER for the two isomers, indicating different reaction pathways resulting in the same final ionic fragments. Our experimental results are interpreted by state-of-the-art ab initio molecular dynamics calculations.