Atomic autoionization in the photo-dissociation of super-excited deuterated water molecules fragmenting into D + O + D

We present the relaxation dynamics of deuterated water molecules via autoionization, initiated by the absorption of a 61 eV photon, producing the very rare D + + O + + D breakup channel. We employ the COLd target recoil ion momentum spectroscopy method to measure the 3D momenta of the ionic fragment...

Full description

Saved in:
Bibliographic Details
Published inPhysical chemistry chemical physics : PCCP Vol. 25; no. 32; pp. 21562 - 21572
Main Authors Iskandar, W, Rescigno, T. N, Orel, A. E, Larsen, K. A, Griffin, B, Call, D, Davis, V, Jochim, B, Severt, T, Williams, J. B, Ben-Itzhak, I, Slaughter, D. S, Weber, Th
Format Journal Article
LanguageEnglish
Published England Royal Society of Chemistry 16.08.2023
Royal Society of Chemistry (RSC)
Subjects
Atomic oxygen
Autoionization
Configuration interaction
Deuteration
Electron energy
Energy distribution
Particle energy
Potential energy
Recoil ions
Water chemistry
Online AccessGet full text

Cover

More Information
Summary:We present the relaxation dynamics of deuterated water molecules via autoionization, initiated by the absorption of a 61 eV photon, producing the very rare D + + O + + D breakup channel. We employ the COLd target recoil ion momentum spectroscopy method to measure the 3D momenta of the ionic fragments and emitted electrons from the dissociating molecule in coincidence. We interpret the results using the potential energy surfaces extracted from multi-reference configuration interaction calculations. The measured particle energy distributions can be related to a super-excited monocationic state located above the double ionization threshold of D 2 O. The autoionized electron energy shows a sharp distribution centered around 0.5 eV, which is a signature of the atomic oxygen autoionization occurring in the direct and sequential dissociation processes of D 2 O + * at a large internuclear distance. In this way, an O + radical fragment and a low-energy electron are created, both of which can trigger secondary reactions in their environment. Creation of a super-excited radical water cation results in a long-lived excited oxygen fragment that can act as a destructive carrier and initiate secondary reactions such as breakup of DNA strands - a key radiation damage mechanism.
Bibliography:ObjectType-Article-1
SourceType-Scholarly Journals-1
ObjectType-Feature-2
content type line 23
USDOE
ISSN:1463-9076
1463-9084
DOI:10.1039/d3cp02438e