Related Experiment Video
Updated: Jan 3, 2026

Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures
Published on: October 9, 2012
High-Resolution Photoelectron Spectroscopy of Cryogenically Cooled NO3̅
Mark C Babin1, Jessalyn A DeVine1, Martin DeWitt1
1Department of Chemistry , University of California , Berkeley , California 94720 , United States.
Abstract:
High-resolution anion photoelectron spectra of cryogenically cooled NO3̅ anions obtained using slow photoelectron velocity-map imaging are presented and provide new insight into the vibronic structure of the corresponding neutral radical. A combination of improved spectral resolution, measurement of energy-dependent intensity effects, temperature control, and comparison to theory allows for full assignment of the vibronic features observed in this spectrum. We obtain a refined electron affinity of 3.9289(14) eV for NO3. Further, the appearance of Franck-Condon forbidden transitions from vibrationally cold anions to neutral states with excitation along the NO3 ν4 mode confirms that these features arise from vibronic coupling with the B̃2E' excited state of NO3 and are not hot bands, as has been suggested. Together, the suite of experimental and simulated results provides clear evidence that the ν3 fundamental of NO3 resides near 1050 cm-1, addressing a long-standing controversy surrounding this vibrational assignment.
Related Concept Videos
Electron Paramagnetic Resonance (EPR) Spectroscopy: Organic Radicals
Cryo-electron Microscopy
Radicals: Electronic Structure and Geometry
Accordingly, the structure of a trivalent radical lies between the geometries of carbocations and carbanions. An sp2-hybridized carbocation is trigonal planar, while an sp3-hybridized carbanion is trigonal pyramidal. Here, the difference in geometry is...
Radical Reactivity: Overview
Radical Reactivity: Steric Effects
Along with electronic...
Radical Formation: Abstraction
Even though homolysis produces radicals, it is different from radical...

