Skip to main content

Lund University Publications

LUND UNIVERSITY LIBRARIES

Time-resolved site-selective imaging of predissociation and charge transfer dynamics : The CH3I B-band

Forbes, Ruaridh ; Allum, Felix ; Bari, Sadia ; Boll, Rebecca ; Borne, Kurtis ; Brouard, Mark ; Bucksbaum, Philip H. ; Ekanayake, Nagitha ; Erk, Benjamin and Howard, Andrew J. , et al. (2020) In Journal of Physics B: Atomic, Molecular and Optical Physics 53(22).
Abstract

The predissociation dynamics of the 6s (B2E) Rydberg state of gas-phase CH3I were investigated by time-resolved Coulomb-explosion imaging using extreme ultraviolet (XUV) free-electron laser pulses. Inner-shell ionization at the iodine 4d edge was utilized to provide a site-specific probe of the ensuing dynamics. The combination of a velocity-map imaging (VMI) spectrometer coupled with the pixel imaging mass spectrometry (PImMS) camera permitted three-dimensional ionic fragment momenta to be recorded simultaneously for a wide range of iodine charge states. In accord with previous studies, initial excitation at 201.2 nm results in internal conversion and subsequent dissociation on the lower-lying A-state surface on a... (More)

The predissociation dynamics of the 6s (B2E) Rydberg state of gas-phase CH3I were investigated by time-resolved Coulomb-explosion imaging using extreme ultraviolet (XUV) free-electron laser pulses. Inner-shell ionization at the iodine 4d edge was utilized to provide a site-specific probe of the ensuing dynamics. The combination of a velocity-map imaging (VMI) spectrometer coupled with the pixel imaging mass spectrometry (PImMS) camera permitted three-dimensional ionic fragment momenta to be recorded simultaneously for a wide range of iodine charge states. In accord with previous studies, initial excitation at 201.2 nm results in internal conversion and subsequent dissociation on the lower-lying A-state surface on a picosecond time scale. Examination of the time-dependent yield of low kinetic energy iodine fragments yields mechanistic insights into the predissociation and subsequent charge transfer following multiple ionization of the iodine products. The effect of charge transfer was observed through differing delay-dependencies of the various iodine charge states, from which critical internuclear distances for charge transfer could be inferred and compared to a classical over-the-barrier model. Time-dependent photofragment angular anisotropy parameters were extracted from the central slice of the Newton sphere, without Abel inversion, and highlight the effect of rotation of the parent molecule before dissociation, as observed in previous

(Less)
Please use this url to cite or link to this publication:
author
; ; ; ; ; ; ; ; and , et al. (More)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ; and (Less)
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Physics B: Atomic, Molecular and Optical Physics
volume
53
issue
22
article number
224001
publisher
IOP Publishing
external identifiers
  • scopus:85094970507
ISSN
0953-4075
DOI
10.1088/1361-6455/abb1fd
language
English
LU publication?
yes
id
f7d3fa35-90dc-41bc-a55d-76adac8b83a6
date added to LUP
2020-11-16 08:00:45
date last changed
2023-12-05 00:21:46
@article{f7d3fa35-90dc-41bc-a55d-76adac8b83a6,
  abstract     = {{<p>The predissociation dynamics of the 6s (B<sup>2</sup>E) Rydberg state of gas-phase CH<sub>3</sub>I were investigated by time-resolved Coulomb-explosion imaging using extreme ultraviolet (XUV) free-electron laser pulses. Inner-shell ionization at the iodine 4d edge was utilized to provide a site-specific probe of the ensuing dynamics. The combination of a velocity-map imaging (VMI) spectrometer coupled with the pixel imaging mass spectrometry (PImMS) camera permitted three-dimensional ionic fragment momenta to be recorded simultaneously for a wide range of iodine charge states. In accord with previous studies, initial excitation at 201.2 nm results in internal conversion and subsequent dissociation on the lower-lying A-state surface on a picosecond time scale. Examination of the time-dependent yield of low kinetic energy iodine fragments yields mechanistic insights into the predissociation and subsequent charge transfer following multiple ionization of the iodine products. The effect of charge transfer was observed through differing delay-dependencies of the various iodine charge states, from which critical internuclear distances for charge transfer could be inferred and compared to a classical over-the-barrier model. Time-dependent photofragment angular anisotropy parameters were extracted from the central slice of the Newton sphere, without Abel inversion, and highlight the effect of rotation of the parent molecule before dissociation, as observed in previous</p>}},
  author       = {{Forbes, Ruaridh and Allum, Felix and Bari, Sadia and Boll, Rebecca and Borne, Kurtis and Brouard, Mark and Bucksbaum, Philip H. and Ekanayake, Nagitha and Erk, Benjamin and Howard, Andrew J. and Johnsson, Per and Lee, Jason W.L. and Manschwetus, Bastian and Mason, Robert and Passow, Christopher and Peschel, Jasper and Rivas, Daniel E. and Rörig, Aljoscha and Rouzée, Arnaud and Vallance, Claire and Ziaee, Farzaneh and Rolles, Daniel and Burt, Michael}},
  issn         = {{0953-4075}},
  language     = {{eng}},
  number       = {{22}},
  publisher    = {{IOP Publishing}},
  series       = {{Journal of Physics B: Atomic, Molecular and Optical Physics}},
  title        = {{Time-resolved site-selective imaging of predissociation and charge transfer dynamics : The CH<sub>3</sub>I B-band}},
  url          = {{http://dx.doi.org/10.1088/1361-6455/abb1fd}},
  doi          = {{10.1088/1361-6455/abb1fd}},
  volume       = {{53}},
  year         = {{2020}},
}