Vibronic structure of the NO3 X~ 2A2' system

Fukushima, Masaru

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https://hdl.handle.net/2142/104453 Copy

Description

Title

Vibronic structure of the NO3 X~ 2A2' system

Author(s)

Fukushima, Masaru

Issue Date

2019-06-18

Keyword(s)

Radicals

Abstract

The $\tilde{X}$ $^2A_2'$ state of NO$_3$ under jet cooled conditions is investigated via laser induced fluorescence (~LIF~) and two-color resonant four-wave mixing (~2C-R4WM~) techniques. The electronic structure of NO$_3$ is thought to be similar to that of BF$_3$, and the latter has been well documented in the literatures\footnote{H.~B.~Gray, Electrons and Chemical Bonding, W.~A.~Benjamin Inc., New York (1965); Open Source Tex Books, https://archive.org/details/ost-chemistry-electrons\_chemical\_bonding (retrieved Feb. 26, 2019).}\footnote{F.~A.~Cotton, Chemical Applications of Group Theory, 2nd ed., Wiley-International, New York (1971).}. The BF$_3$ highest occupied molecular orbital (~HOMO~) possesses peculiar electronic structure with orbital localization on each of three F’s and no contribution on the center atom, B. For NO$_3$, the HOMO corresponds to a singly occupied molecular orbital (~SOMO~), and, in the $\tilde{X}$ $^2A_2'$ state (~$\tilde{A}$ $^2E''$ and $\tilde{B}$ $^2E'$, too~) of NO$_3$, the un-paired electron is localized on the three O’s and has no contribution on N. For this state, the degenerate vibrations are naturally expected to strongly affect the electron motion, which can be referred to as ”degenerate-vibrationally induced vibronic coupling” on the non-degenerate electronic state. The SOMO characteristics of NO$_3$ have been confirmed by high-level quantum chemical computation\footnote{W.~Eisfeld and K.~Morokuma, $J.~Chem.~Phys.$ 113, 5587 (2000).}. The characteristic features of the vibrational structure of the $\tilde{X}$ $^2A_2'$ state may possibly be understood by the vibronic coupling. One feature is an unexpectedly large spin splitting of $1_0$ (~= $N_K$~) of the 3$\nu_4$ ($a_1'$) level observed by 2C-R4WM\footnote{M.~Fukushima and T.~Ishiwata, 73rd ISMS, paper WD02 (2018).}, and this splitting can be understood as the good quantum number behavior of $P$ (~$= K_v + \Sigma = \Lambda + l + \Sigma$~) derived from the coupling.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/104453

DOI

https://doi.org/10.15278/isms.2019.TD07

Copyright and License Information

Copyright 2019 Masaru Fukushima

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