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Published on: May 29, 2018
Attosecond spectroscopy reveals alignment dependent core-hole dynamics in the ICl molecule
Hugo J B Marroux1,2,3, Ashley P Fidler4,5, Aryya Ghosh6
1Department of Chemistry, University of California, Berkeley, CA, 94720, USA. hugo.marroux@epfl.ch.
Studying transient states in iodine monochloride reveals core-excited state lifetimes. Attosecond transient absorption shows shorter lifetimes for states aligned with the molecular axis due to electronic interactions.
Area of Science:
- * Quantum dynamics
- * Molecular spectroscopy
- * Attosecond science
Background:
- * Core-shell electron removal creates short-lived molecular states (femtoseconds to attoseconds).
- * Observing dynamics in these transient states is experimentally challenging.
- * Electronic correlation plays a key role in molecular behavior.
Purpose of the Study:
- * To measure core-excited state lifetimes in iodine monochloride (ICl).
- * To investigate the influence of molecular orientation on these lifetimes.
- * To understand the role of electronic interactions in transient state dynamics.
Main Methods:
- * Attosecond transient absorption spectroscopy.
- * Probing iodine 4d-16p transitions in ICl around 55 eV.
- * Utilizing core-level ligand field splitting to access different excited states.
Main Results:
- * Measured core-excited state lifetimes of ICl ranging from 3.5 to 6.9 femtoseconds.
- * Observed significantly shorter lifetimes for states aligned parallel (3.5 ± 0.4 fs, 4.3 ± 0.4 fs) versus perpendicular (6.5 ± 0.6 fs, 6.9 ± 0.6 fs) to the molecular axis.
- * Nuclear motion remained largely static during these short lifetimes.
Conclusions:
- * Core-excited state lifetimes in ICl are highly dependent on their alignment relative to the molecular bond.
- * Shorter lifetimes for parallel-aligned states are attributed to non-local interactions with the chlorine atom.
- * Provides insights into ultrafast molecular dynamics driven by electronic correlation.
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