Time-Dependent UV-Induced Dynamics in 2-Bromothiophene*

We will present an experimental study of time-resolved ultrafast nuclear dynamics in 2-Bromothiophene (2-C₄H₃BrS), observed with 240nm UV pump-800nm IR probe spectroscopy and coincident Coulomb explosion imaging using a Cold Target Recoil Ion Momentum Spectrometer (COLTRIMS). We have identified two- and three- body molecular fragmentation channels that show dynamics ranging from direct bromine dissociation to ring fragmentation. Further analysis was done of the momentum vectors of the ion fragments to show unique fragmentation pathways the molecule can undergo to achieve the same final ion products – including the potential for ring-opening prior to fragmentation. The work is complemented by theoretical calculations performed by the Golubev group at the University of Arizona. We will conclude by proposing further studies to compare with the conformer 3-Bromothiophene and using different UV photon energies to excite the molecule.