High-Resolution Photoelectron Spectroscopy of Cryogenically Cooled NO3̅

Mark C Babin; Jessalyn A DeVine; Martin DeWitt; John F Stanton; Daniel M Neumark

doi:10.1021/acs.jpclett.9b03055

High-Resolution Photoelectron Spectroscopy of Cryogenically Cooled NO₃̅

J Phys Chem Lett. 2020 Jan 16;11(2):395-400. doi: 10.1021/acs.jpclett.9b03055. Epub 2019 Dec 30.

Authors

Mark C Babin¹, Jessalyn A DeVine¹, Martin DeWitt¹, John F Stanton², Daniel M Neumark^{1

3}

Affiliations

¹ Department of Chemistry , University of California , Berkeley , California 94720 , United States.
² Quantum Theory Project, Department of Chemistry and Physics , University of Florida , Gainesville , Florida 32611 , United States.
³ Chemical Sciences Division , Lawrence Berkeley National Laboratory , Berkeley , California 94720 , United States.

PMID: 31765169
DOI: 10.1021/acs.jpclett.9b03055

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.