Related Experiment Video
Updated: Aug 7, 2026

Photoelectron Imaging of Anions Illustrated by 310 Nm Detachment of F−
Published on: July 27, 2018
Slow electron velocity-map imaging photoelectron spectra of the methoxide anion
Matthew J Nee1, Andreas Osterwalder, Jia Zhou
1Department of Chemistry, University of California, Berkeley, California 94720, USA.
Abstract:
High resolution anion photodetachment spectra are presented for the methoxide anion and its fully deuterated counterpart. The spectra were obtained with slow electron velocity-map imaging. Improved electron affinities are determined for CH3O as 1.5690+/-0.0019 eV and for CD3O as 1.5546+/-0.0019 eV. The spectra resolve many features associated with spin-orbit and vibronic coupling that were not seen in previous photodetachment studies. Photoelectron angular distributions taken as a function of detachment wavelength for the ground vibronic state transitions are recorded and are consistent with the removal of a nonbonding, p-type electron localized on the oxygen atom. Several hot bands and sequence bands are observed for the first time, providing insight into the vibrational structure of the methoxide anion. The results are compared to recent calculations of the anion photoelectron spectra that incorporate bilinear coupling terms among the methoxy vibrational modes and are found to be in reasonable agreement.
Related Concept Videos
UV–Vis Spectroscopy: Molecular Electronic Transitions
π Electron Effects on Chemical Shift: Overview
Chemical Ionization (CI) Mass Spectrometry
Molecular Spectroscopy: Absorption and Emission
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
Mass Spectrum: Interpretation

