Related Experiment Video
Updated: May 13, 2026

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
Mechanisms for the near-UV photodissociation of CH3I on D2O/Cu(110)
E R Miller1, G D Muirhead, E T Jensen
1Physics Department, University of Northern British Columbia, 3333 University Way, Prince George, British Columbia V2N 4Z9, Canada.
Abstract:
The system of CH3I adsorbed on submonolayer, monolayer, and multilayer thin films of D2O on Cu(110) has been studied by measuring the time of flight (TOF) distributions of the desorbing CH3 fragments after photodissociation using linearly polarized λ = 248 nm light. For multilayer D2O films (2-120 ML), the photodissociation is dominated by neutral photodissociation via the "A-band" absorption of CH3I. The polarization and angle dependent variation in the observed TOF spectra of the CH3 photofragments find that dissociation is largely via the (3)Q0 excited state, but that also a contribution via the (1)Q1 excitation can be identified. The photodissociation results also indicate that the CH3I adsorbed on D2O forms close-packed islands at submonolayer coverages, with a mixture of C-I bond axis orientations. For monolayer and submonolayer quantities of D2O we have observed a contribution to CH3I photodissociation via dissociative electron attachment (DEA) by photoelectrons. The observed DEA is consistent with delocalized photoelectrons from the substrate causing the observed dissociation- we do not find evidence for an enhanced DEA mechanism via the temporary solvation of photoelectrons in localized states of the D2O ice.
Related Concept Videos
E1 Reaction: Kinetics and Mechanism
Chemical Ionization (CI) Mass Spectrometry
Radical Substitution: Hydrogenolysis of Alkyl Halides with Tributyltin Hydride
The bonds formed in this reaction are stronger than the bonds broken, making it energetically favorable. The reaction follows a radical chain mechanism similar to radical halogenation reactions,...
Cycloaddition Reactions: MO Requirements for Photochemical Activation
Regioselectivity and Stereochemistry of Acid-Catalyzed Hydration
UV–Vis Spectroscopy: Woodward–Fieser Rules

![[(DPEPhos)(bcp)Cu]PF6: A General and Broadly Applicable Copper-Based Photoredox Catalyst](/_next/image?url=https%3A%2F%2Fcloudfront.jove.com%2FCDNSource%2Fteasers%2F59739.jpg&w=3840&q=50)