Related Experiment Video
Updated: Apr 18, 2026

Measurement and Analysis of Atomic Hydrogen and Diatomic Molecular AlO, C2, CN, and TiO Spectra Following Laser-induced Optical Breakdown
Published on: February 14, 2014
VUV photoionization cross sections of HO2, H2O2, and H2CO
Leah G Dodson1, Linhan Shen, John D Savee
1Division of Chemistry and Chemical Engineering and §NASA Jet Propulsion Laboratory, California Institute of Technology , Pasadena, California 91125, United States.
Abstract:
The absolute vacuum ultraviolet (VUV) photoionization spectra of the hydroperoxyl radical (HO2), hydrogen peroxide (H2O2), and formaldehyde (H2CO) have been measured from their first ionization thresholds to 12.008 eV. HO2, H2O2, and H2CO were generated from the oxidation of methanol initiated by pulsed-laser-photolysis of Cl2 in a low-pressure slow flow reactor. Reactants, intermediates, and products were detected by time-resolved multiplexed synchrotron photoionization mass spectrometry. Absolute concentrations were obtained from the time-dependent photoion signals by modeling the kinetics of the methanol oxidation chemistry. Photoionization cross sections were determined at several photon energies relative to the cross section of methanol, which was in turn determined relative to that of propene. These measurements were used to place relative photoionization spectra of HO2, H2O2, and H2CO on an absolute scale, resulting in absolute photoionization spectra.
More Related Videos
Related Concept Videos
UV–Vis Spectroscopy: Molecular Electronic Transitions
UV–Vis Spectroscopy of Conjugated Systems
One of the factors influencing λmax is...
UV–Vis Spectroscopy: Woodward–Fieser Rules
Hess's Law
Ultraviolet and Visible (UV–Vis) Spectroscopy: Overview
UV–Vis Spectrometers

