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Photodissociation of aligned CH3I and C6H3F2I molecules probed with time-resolved Coulomb explosion imaging by site-selective extreme ultraviolet ionization

Amini, Kasra; Savelyev, Evgeny; Brauße, Felix; Berrah, Nora; Bomme, Cédric; Brouard, Mark; Burt, Michael; Christensen, Lauge; Düsterer, Stefan and Erk, Benjamin, et al. (2018) In Structural Dynamics 5(1).
Abstract

We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a 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... (More)

We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a 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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@article{521de113-248b-41fd-b575-fa53ae50c4ba,
  abstract     = {<p>We explore time-resolved Coulomb explosion induced by intense, extreme ultraviolet (XUV) femtosecond pulses from a 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.</p>},
  articleno    = {4998648},
  author       = {Amini, Kasra and Savelyev, Evgeny and Brauße, Felix and Berrah, Nora and Bomme, Cédric and Brouard, Mark and Burt, Michael and Christensen, Lauge and Düsterer, Stefan and Erk, Benjamin and Höppner, Hauke and Kierspel, Thomas and Krecinic, Faruk and Lauer, Alexandra and Lee, Jason W.L. and Müller, Maria and Müller, Erland and Mullins, Terence and Redlin, Harald and Schirmel, Nora and Thøgersen, Jan and Techert, Simone and Toleikis, Sven and Treusch, Rolf and Trippel, Sebastian and Ulmer, Anatoli and Vallance, Claire and Wiese, Joss and Johnsson, Per and Küpper, Jochen and Rudenko, Artem and Rouzée, Arnaud and Stapelfeldt, Henrik and Rolles, Daniel and Boll, Rebecca},
  issn         = {2329-7778},
  language     = {eng},
  month        = {01},
  number       = {1},
  publisher    = {American Institute of Physics},
  series       = {Structural Dynamics},
  title        = {Photodissociation of aligned CH<sub>3</sub>I and C<sub>6</sub>H<sub>3</sub>F<sub>2</sub>I molecules probed with time-resolved Coulomb explosion imaging by site-selective extreme ultraviolet ionization},
  url          = {http://dx.doi.org/10.1063/1.4998648},
  volume       = {5},
  year         = {2018},
}