X-ray induced fragmentation of fulminic acid, HCNO

Marius Gerlach; Dorothee Schaffner; Tobias Preitschopf; Emil Karaev; John Bozek; Fabian Holzmeier; Ingo Fischer

doi:10.1063/5.0167395

X-ray induced fragmentation of fulminic acid, HCNO

J Chem Phys. 2023 Sep 21;159(11):114306. doi: 10.1063/5.0167395.

Authors

Marius Gerlach¹, Dorothee Schaffner¹, Tobias Preitschopf¹, Emil Karaev¹, John Bozek², Fabian Holzmeier³, Ingo Fischer¹

Affiliations

¹ Institute of Physical and Theoretical Chemistry, University of Würzburg, 97074 Würzburg, Germany.
² Synchrotron SOLEIL, 91192 Gif-sur-Yvette, France.
³ Imec, 3001 Leuven, Belgium.

PMID: 37721327
DOI: 10.1063/5.0167395

Abstract

The fragmentation of fulminic acid, HCNO, after excitation and ionization of core electrons was investigated using Auger-electron-photoion coincidence spectroscopy. A considerable degree of site-selectivity is observed. Ionization of the carbon and oxygen 1s electron leads to around 70% CH+ + NO+, while ionization at the central N-atom produces only 37% CH+ + NO+, but preferentially forms O+ + HCN+ and O+ + CN+. The mass-selected Auger-electron spectra show that these fragments are associated with higher binding energy final states. Furthermore, ionization of the C 1s electron leads to a higher propensity for C-H bond fission compared to O 1s ionization. Following resonant Auger-Meitner decay after 1s → 3π excitation, 12 different ionic products are formed. At the C 1s edge, the parent ion HCNO+ is significantly more stable compared to the other two edges, which we also attribute to the higher contribution of final states with low binding energies in the C 1s resonant Auger electron spectra.