Abstract
We studied the fragmentation of planar formic acid (HCOOH) molecules following their double ionization by intense ultrashort laser pulses. Deuterium tagging (i.e., HCOOD) combined with coincidence momentum imaging measurements of all fragment ions enabled determination of the role of the hydroxyl and carboxyl hydrogen atoms in the breakup. Specifically, we observe a strong preference for the hydroxyl (OD) group to remain intact in a fragmentation, which is an order of magnitude more likely than . An even larger preference for breaking the H-C bond over the O-H bond is observed in the and deprotonation channels. Bond rearrangement, leading to or formation, exhibits no isotopic preference. The kinetic-energy-release distributions of the and breakup channels suggest that more than one process contributes to these final products, although further theoretical work is needed to identify the specific paths.
2 More- Received 4 October 2021
- Revised 1 April 2022
- Accepted 28 April 2022
DOI:https://doi.org/10.1103/PhysRevA.105.053112
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