Photofragmentation of gas-phase acetic acid and acetamide clusters in the vacuum ultraviolet region

: Marta Berholts, Hanna Myllynen, Kuno Kooser, Eero Itälä, Sari Granroth, Helena Levola, Joakim Laksman, Shabnam Oghbaiee, Bart Oostenrijk, Ergo Nõmmiste, Edwin Kukk

Publisher: A I P Publishing LLC

: 2017

: Journal of Chemical Physics

: JOURNAL OF CHEMICAL PHYSICS

: J CHEM PHYS

: ARTN 194302

: 147

: 19

: 12

: 0021-9606

: 1089-7690

DOI: https://doi.org/10.1063/1.4999686

Photofragmentation of gas-phase acetamide and acetic acid clusters produced by a supersonic expansion source has been studied using time-of-flight mass spectrometry and the partial ion yield (PIY) technique combined with tunable vacuum-ultraviolet synchrotron radiation. Appearance energies of the clusters and their fragments were experimentally determined from the PIY measurements. The effect of clusterization conditions on the formation and fragmentation of acetic acid clusters was investigated. Ab initio quantum mechanical calculations were performed on both samples' dimers to find their neutral and ionized geometries as well as proton transfer energy barriers leading to the optimal geometries. In the case of the acetamide dimer, the reaction resulting in the production of ammoniated acetamide was probed, and the geometry of the obtained ion was calculated. Published by AIP Publishing.