Speaker
Description
Disruptive probing reveals reaction pathways that are hidden in conventional mass spectra by following how a delayed laser pulse redirects evolving molecular ions and clusters into specific fragment channels [1]. Here we combine femtosecond strong-field ionization, time-resolved mass spectrometry, and ab initio molecular dynamics simulations to investigate H3+ formation in methylamine, methanol, and ethanol. This comparison shows that H3+ production is strongly influenced by the hydrogen bound to the heteroatom, whose role changes across the amine and alcohol series as molecular structure controls hydrogen migration, H2 roaming, and proton-abstraction pathways. We then extend the approach to methanol and ethanol clusters, where hydrogen bonding opens intermolecular proton-transfer and relaxation pathways not available in isolated molecules. In ethanol clusters, disruptive probing also identifies channels in which ethanol undergoes demethylation, revealing additional fragmentation pathways enabled by clustering. Together, these results show that disruptive probing provides a general strategy for uncovering hidden ultrafast reaction pathways in molecular ions and clusters.