Conformer-specific Infrared spectroscopy of cationic Criegee intermediates syn- and anti-CH3CHOO+

This is the authors' abstract. We don't add key points for this paper.

Criegee intermediates are pivotal in atmospheric chemistry, yet their cationic forms remain poorly understood. This study presents the infrared spectra of cationic Criegee intermediates, specifically syn- and anti-CH3CHOO+, using vacuum ultraviolet photoionization coupled with IR photon dissociation spectroscopy. Combined with quantum chemistry calculations, we explore conformer-specific infrared spectra and identify distinct unimolecular reaction pathways for each conformer. Our method reveals structural differences between neutral and cationic CH3CHOO, including a lower isomerization barrier in the cationic form. This approach enables the investigation of conformer-specific IR spectroscopy for cationic species, which is challenging using direct IR absorption methods. By exploiting these distinct reaction pathways, we can conduct conformer-specific spectroscopic studies, advancing our ability to trace specific molecular conformations in complex chemical processes in both atmospheric and interstellar contexts. Criegee intermediates are pivotal in atmospheric chemistry, yet their cationic forms remain poorly understood. Here, the authors present infrared spectra of cationic Criegee intermediates, specifically syn- and anti-CH3CHOO+, using vacuum ultraviolet photoionization coupled with IR photon dissociation spectroscopy.