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arXiv · 1708.00676

Probing the UV-Induced Photodissociation of CH$_\text{3}$I and C$_\text{6}$H$_\text{3}$F$_\text{2}$I with Femtosecond Time-Resolved Coulomb Explosion Imaging at FLASH

Kasra Amini·Evgeny Savelyev·Felix Brauße·Nora Berrah·Cédric Bomme·Mark Brouard·Michael Burt·Lauge Christensen·Stefan Düsterer·Benjamin Erk·Hauke Höppner·Thomas Kierspel·Faruk Krecinic·Alexandra Lauer·Jason W. L. Lee·Maria Müller·Erland Müller·Terence Mullins·Harald Redlin·Nora Schirmel·Jan Thøgersen·Simone Techert·Sven Toleikis·Rolf Treusch·Sebastian Trippel·Anatoli Ulmer·Claire Vallance·Joss Wiese·Per Johnsson·Jochen Küpper·Artem Rudenko·Arnaud Rouzée·Henrik Stapelfeldt·Daniel Rolles·Rebecca Boll
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Abstract

We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from the FLASH free-electron laser as a method to image photo-induced molecular dynamics in two molecules, iodomethane and 2,6-difluoroiodobenzene. At an excitation wavelength of 267\,nm, the dominant reaction pathway in both molecules is neutral dissociation via cleavage of the carbon--iodine bond. This allows investigating the influence of the molecular environment on the absorption of an intense, femtosecond XUV pulse and the subsequent Coulomb explosion process. We find that the XUV probe pulse induces local inner-shell ionization of atomic iodine in dissociating iodomethane, in contrast to non-selective ionization of all photofragments in difluoroiodobenzene. The results reveal evidence of electron transfer from methyl and phenyl moieties to a multiply charged iodine ion. In addition, indications for ultrafast charge rearrangement on the phenyl radical are found, suggesting that time-resolved Coulomb explosion imaging is sensitive to the localization of charge in extended molecules.

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Kasra Amini, Evgeny Savelyev, Felix Brauße, Nora Berrah, Cédric Bomme, Mark Brouard, Michael Burt, Lauge Christensen, Stefan Düsterer, Benjamin Erk, Hauke Höppner, Thomas Kierspel, Faruk Krecinic, Alexandra Lauer, Jason W. L. Lee, Maria Müller, Erland Müller, Terence Mullins, Harald Redlin, Nora Schirmel, Jan Thøgersen, Simone Techert, Sven Toleikis, Rolf Treusch, Sebastian Trippel, Anatoli Ulmer, Claire Vallance, Joss Wiese, Per Johnsson, Jochen Küpper, Artem Rudenko, Arnaud Rouzée, Henrik Stapelfeldt, Daniel Rolles, Rebecca Boll. 2018-01-30. Probing the UV-Induced Photodissociation of CH$_\text{3}$I and C$_\text{6}$H$_\text{3}$F$_\text{2}$I with Femtosecond Time-Resolved Coulomb Explosion Imaging at FLASH. https://doi.org/10.1063/1.4998648

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