Angular Distribution of Ion Products in the Double Photoionization of Propylene Oxide.

Autor: Falcinelli S; Department of Civil and Environmental Engineering, University of Perugia, Perugia, Italy., Rosi M; Department of Civil and Environmental Engineering, University of Perugia, Perugia, Italy., Pirani F; Department of Chemistry, Biology and Biotechnologies, University of Perugia, Perugia, Italy., Bassi D; Department of Physics, University of Trento, Trento, Italy., Alagia M; IOM-CNR Tasc, Trieste, Italy., Schio L; IOM-CNR Tasc, Trieste, Italy.; Department of Basic and Applied Sciences for Engineering (SBAI), University of Rome 'Sapienza', Rome, Italy., Richter R; Elettra-Sincrotrone Trieste, Trieste, Italy., Stranges S; IOM-CNR Tasc, Trieste, Italy.; Department of Chemistry and Drug Technologies, University of Rome 'Sapienza', Rome, Italy., Balucani N; Department of Chemistry, Biology and Biotechnologies, University of Perugia, Perugia, Italy., Lorent V; Laboratoire de physique des lasers, Université Paris 13 (UP13) - Institut Galilée - CNRS LPL UMR7538, Villetaneuse, France., Vecchiocattivi F; Department of Civil and Environmental Engineering, University of Perugia, Perugia, Italy.
Jazyk: angličtina
Zdroj: Frontiers in chemistry [Front Chem] 2019 Sep 11; Vol. 7, pp. 621. Date of Electronic Publication: 2019 Sep 11 (Print Publication: 2019).
DOI: 10.3389/fchem.2019.00621
Abstrakt: A photoelectron-photoion-photoion coincidence technique, using an ion imaging detector and tunable synchrotron radiation in the 18.0-37.0 eV photon energy range, inducing the ejection of molecular valence electrons, has been applied to study the double ionization of the propylene oxide, a simple prototype chiral molecule. The experiment performed at the Elettra Synchrotron Facility (Trieste, Italy) allowed to determine angular distributions for ions produced by the two-body dissociation reactions following the Coulomb explosion of the intermediate (C 3 H 6 O) 2+ molecular dication. The analysis of the coincidence spectra recorded at different photon energies was done in order to determine the dependence of the β anisotropy parameter on the photon energy for the investigated two-body fragmentation channels. In particular, the reaction leading to CH 3 + + C 2 H 3 O + appears to be characterized by an increase of β , from β ≈ 0.00 up to β = 0.59, as the photon energy increases from 29.7 to 37.0 eV, respectively. This new observation confirms that the dissociation channel producing CH 3 + and C 2 H 3 O + final ions can occur with two different microscopic mechanisms as already indicated by the bimodality obtained in the kinetic energy released (KER) distributions as a function of the photon energy in a recent study. Energetic considerations suggest that experimental data are compatible with the formation of two different stable isomers of C 2 H 3 O + : acetyl and oxiranyl cations. These new experimental data are inherently relevant and are mandatory information for further experimental and theoretical investigations involving oriented chiral molecules and linearly or circularly polarized radiation. This work is in progress in our laboratory.
(Copyright © 2019 Falcinelli, Rosi, Pirani, Bassi, Alagia, Schio, Richter, Stranges, Balucani, Lorent and Vecchiocattivi.)
Databáze: MEDLINE
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