UV-induced dissociation of CH2BrI probed by intense femtosecond XUV pulses

Hansjochen Köckert (1) , Jason Lee , Felix Allum , Kasra Amini (1) , Sadia Bari (2) , Cédric Bomme (3, 4) , Felix Brauße (5) , Mark Brouard (1) , Michael Burt , Barbara Cunha de Miranda (6) , Stefan Düsterer (7) , Per Eng-Johnsson (8) , Benjamin Erk (7) , Marie Géléoc (4) , Romain Geneaux (4, 9) , Alexander Gentleman (1) , Renaud Guillemin (10) , Gildas Goldsztejn (10, 5) , David Holland , Iyas Ismail (10) , Loïc Journel (10) , Thomas Kierspel (11, 12) , Jochen Küpper (11, 12) , Jan Lahl (8) , Stuart Mackenzie (1) , Sylvain Maclot (8) , Bastian Manschwetus (13) , Andrey Mereshchenko (14) , Terence Mullins (11) , Pavel Olshin (14) , Jérôme Palaudoux (10) , Francis Penent (10) , Maria Novella Piancastelli (15) , Dimitrios Rompotis (13, 16) , Arnaud Rouzée (5) , Thierry Ruchon (4, 9) , Artem Rudenko (17) , Nora Schirmel (13) , Marc Simon (10) , Simone Techert (13) , Oksana Travnikova (10) , Sebastian Trippel (11) , Claire Vallance , Enliang Wang (17) , Joss Wiese (13, 11, 12) , Farzaneh Ziaee (17) , Tatiana Marchenko (10) , Daniel Rolles (17) , Rebecca Boll (16)

1 University of Oxford
2 Deutsches Elektronen-Synchrotron DESY
3 PHI - Physique à Haute Intensité
4 LIDYL - Laboratoire Interactions, Dynamiques et Lasers (ex SPAM)
5 Max-Born-institut, Berlin
6 DyR - Dynamique Réactionnelle
7 DESY - Deutsches Elektronen-Synchrotron [Hamburg]
8 Skane University Hospital [Lund]
9 ATTO - Attophysique
10 LCPMR - Laboratoire de Chimie Physique - Matière et Rayonnement
11 CFEL - Center for Free-Electron Laser Science
12 UHH - Universität Hamburg
13 DESY - Deutsches Elektronen-Synchrotron [Zeuthen]
14 SPBU - Saint Petersburg State University
15 Department of Physics and Astronomy [Uppsala]
16 European XFEL Gmbh
17 Kansas State University

The ultraviolet (UV)-induced dissociation and photofragmentation of gas-phase CH2BrI molecules induced by intense femtosecond extreme ultraviolet (XUV) pulses at three different photon energies are studied by multi-mass ion imaging. Using a UV-pump–XUV-probe scheme, charge transfer between highly charged iodine ions and neutral CH2Br radicals produced by C–I bond cleavage is investigated. In earlier charge-transfer studies, the center of mass of the molecules was located along the axis of the bond cleaved by the pump pulse. In the present case of CH2BrI, this is not the case, thus inducing a rotation of the fragment. We discuss the influence of the rotation on the charge transfer process using a classical over-the-barrier model. Our modeling suggests that, despite the fact that the dissociation is slower due to the rotational excitation, the critical interatomic distance for charge transfer is reached faster. Furthermore, we suggest that charge transfer during molecular fragmentation may be modulated in a complex way.

Mots clés: free-electron lasers; charge transfer; ultrafast molecular dynamics; free-electron lasers

Domaines: Chimie théorique et/ou physique

Hansjochen Köckert, Jason Lee, Felix Allum, Kasra Amini, Sadia Bari, et al.. UV-induced dissociation of CH2BrI probed by intense femtosecond XUV pulses. Journal of Physics B: Atomic, Molecular and Optical Physics, 2022, 55 (1), pp.014001. ⟨10.1088/1361-6455/ac489d⟩. ⟨hal-03797396⟩