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Dynamics of core-excited ammonia: disentangling fragmentation pathways by complementary spectroscopic methods
Oksana Travnikova1, Farzad Hosseini1,2, Tatiana Marchenko1
1Sorbonne Université, CNRS, UMR 7614, Laboratoire de Chimie Physique-Matière et Rayonnement, F-75005 Paris, France.
Physical Chemistry Chemical Physics : PCCP
|November 16, 2022
Summary
Investigating core-excited ammonia fragmentation using resonant Auger spectroscopy and AEPICO revealed distinct dissociation pathways. This study identified more NH2+ fragment electronic states than previously known.
Area of Science:
- * Molecular physics and spectroscopy
- * Quantum chemistry and dynamics
- * Atomic and molecular interactions
Background:
- * Core-excitation of molecules initiates complex fragmentation dynamics.
- * Understanding dissociation pathways is crucial for molecular physics.
- * Isolated ammonia (NH3) presents a model system for studying core-level dynamics.
Purpose of the Study:
- * To investigate the fragmentation dynamics of core-excited ammonia molecules.
- * To differentiate between ultrafast dissociation (UFD) and relaxation-mediated fragmentation.
- * To identify and characterize electronic states of fragment ions, specifically NH2+.
Main Methods:
- * High-resolution resonant Auger spectroscopy.
- * Electron energy-selected Auger electron-photoion coincidence spectroscopy (AEPICO).
- * Combined application of complementary spectroscopic and coincidence techniques.
Main Results:
- * Resonant Auger spectra provided signatures for both molecular and fragment final states.
- * AEPICO enabled correlation of Auger electrons with specific ionic fragments and electronic states.
- * The study successfully identified multiple electronic states of the NH2+ fragment, exceeding previous reports.
Conclusions:
- * The synergistic use of resonant Auger spectroscopy and AEPICO offers comprehensive insights into molecular fragmentation.
- * Ultrafast dissociation (UFD) and post-relaxation fragmentation pathways were elucidated.
- * This research significantly advances the understanding of core-excited ammonia dissociation and fragment ion characterization.
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