Mapping Molecular Excited States via Relative Ion Yield Photodissociation Spectroscopy
- 17 April 2026
- journal article
- Published by Wiley in Chemphyschem
- Vol. 27 (8) , e202500649
Abstract
Laser photodissociation spectroscopy of gaseous ions is a widely applicable technique used to investigate the electronic excited states and photochemistry of charged systems ranging from inorganic nanoclusters through to biomolecules. Spectra obtained by this technique provide important benchmarks for theoretical studies of dissociative excited states and give insight into light‐induced fragmentation pathways. In this concept article, we will highlight the advantages of obtaining and analysing photodissociation action spectra in terms of photon‐energy‐dependent relative ion yield plots . This new approach to analysing ion photodissociation spectra has been demonstrated by our laboratory over recent years and is based on the photochemical concept of quantum yields. Importantly, relative ion yield analysis allows experimental vertical excitation energies of charged systems to be straightforwardly identified for comparison to theory. The application of relative ion yield analysis also provides greater insight into excited‐state decay dynamics than is evident from inspection of individual photofragment action spectra. To provide a suitable introduction to the relative ion yield concept for non‐expert readers, we begin the article by reviewing the broader topic of ionic photofragment action spectroscopy. Results from several UV filter molecules are then presented to illustrate the advantages of relative ion yield analysis.Keywords
Funding Information
- Engineering and Physical Sciences Research Council (EPSRC (EP/X010724/1))
This publication has 52 references indexed in Scilit:
- Machine learning methods in photochemistry and photophysics2023
- Experimental techniques and terminology in gas‐phase ion spectroscopyJournal of Mass Spectrometry, 2022
- UV‐vis spectroscopy of gas‐phase ionsMass Spectrometry Reviews, 2021
- Electronic States and Nonradiative Decay of Cold Gas-Phase Cinnamic Acid Derivatives Studied by Laser Spectroscopy with a Laser-Ablation TechniqueThe Journal of Physical Chemistry A, 2020
- Direct Measurement of the Visible to UV Photodissociation Processes for the PhotoCORM TryptoCORMChemistry – A European Journal, 2020
- Unravelling the Keto–Enol Tautomer Dependent Photochemistry and Degradation Pathways of the Protonated UVA Filter AvobenzoneThe Journal of Physical Chemistry A, 2020
- Molecular Photochemistry: Recent Developments in TheoryAngewandte Chemie International Edition, 2020
- An automatic variable laser attenuator for IRMPD spectroscopy and analysis of power-dependence in fragmentation spectraInternational Journal of Mass Spectrometry, 2019
- Direct Observation of Photochemical Free Radical Production from the Sunscreen 2‐Phenylbenzimidazole‐5‐Sulfonic Acid via Laser‐Interfaced Mass SpectrometryChemPhotoChem, 2019
- Visible photodissociation spectra of gaseous rhodamine ions: Effects of temperature and taggingJournal of Molecular Spectroscopy, 2017