Photoinduced Neutral Roaming and Hydrogen Migration in Methanol

We will present an experimental study of time-resolved ultrafast dynamics in methanol (CH₃OH), observed with IR-IR (800nm) pump-probe spectroscopy and coincident Coulomb explosion imaging using a Cold Target Recoil Ion Momentum Spectrometer (COLTRIMS). We have identified molecular fragmentation channels that show dynamics corresponding to both single and double hydrogen migration leading to the formation of both H₂O⁺ and H₃O⁺. Additionally, we have reconstructed the momentum vector of a neutral H₂ to show an unambiguous experimental signature of roaming that leads to the formation of H₃⁺. This work is complemented by quantum chemistry calculations that discuss the conditions required of the molecule to yield either hydrogen migration or roaming. As an outlook, we conclude by proposing further studies that can be done to compare roaming and hydrogen migration channel yields in larger alcohol group molecules.