Unimolecular decomposition of methyl ketene and its dimer in the gas phase: theory and experiment - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Physical Chemistry Chemical Physics Année : 2020

Unimolecular decomposition of methyl ketene and its dimer in the gas phase: theory and experiment

Résumé

We present a combined theoretical and experimental investigation on the single photoionization and dissociative photoionization of gas-phase methyl ketene (MKE) and its neutral dimer (MKE2). The performed experiments entail the recording of photoelectron photoion coincidence (PEPICO) spectra and slow photoelectron spectra (SPES) in the energy regime 8.7-15.5 eV using linearly polarized synchrotron radiation. We observe both dimerization and trimerization of the monomer which brings about significantly complex and abstruse dissociative ionization patterns. These require the implementation of theoretical calculations to explore the potential energy surfaces of the monomer and dimer's neutral and ionized geometries. To this end, explicitly correlated quantum chemical methodologies involving the coupled cluster with single, double and perturbative triple excitations (R)CCSD(T)-F12 method, are utilized. An improvement in the adiabatic ionization energy of MKE is presented (AIE = 8.937 ± 0.020 eV) as well as appearance energies for multiple fragments formed through dissociative ionization of either the MKE monomer or dimer. In this regard, the synergy of experiment and theory is crucial to interpreting the obtained results. We discuss the potential astrochemical implications of this work in the context of recent advances in the field of astrochemistry and speculate on the potential presence and eventual fate of interstellar MKE molecules.

Domaines

Chimie
Fichier principal
Vignette du fichier
Derbali et al-2020-Unimolecular decomposition of methyl ketene.pdf (5.74 Mo) Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)

Dates et versions

hal-02959792 , version 1 (17-11-2020)

Identifiants

Citer

Imene Derbali, Helgi Rafn Hrodmarsson, Martin Schwell, Y Benilan, Lionel Poisson, et al.. Unimolecular decomposition of methyl ketene and its dimer in the gas phase: theory and experiment. Physical Chemistry Chemical Physics, 2020, 22 (36), pp.20394-20408. ⟨10.1039/d0cp03921g⟩. ⟨hal-02959792⟩
106 Consultations
88 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More