The electronic spectrum and molecular geometry of the jet-cooled stibino (SbH2) free radical

Sunahori, Fumie X.

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https://hdl.handle.net/2142/104546 Copy

Description

Title

The electronic spectrum and molecular geometry of the jet-cooled stibino (SbH2) free radical

Author(s)

Sunahori, Fumie X.

Contributor(s)

• Smith, Tony
• Clouthier, Dennis

Issue Date

2019-06-18

Keyword(s)

Radicals

Abstract

The jet-cooled stibino (SbH$_{2}$) free radical has been detected for the first time. This highly reactive species was produced in an electric discharge through a precursor mixture of stibine (SbH$_{3}$) diluted in high pressure argon. Stibine was synthesized by the low-temperature reduction of SbCl$_{3}$ with LiAlH$_{4}$ and stored and handled at -85 $^{o}$C to avoid decomposition. Low-resolution LIF scans revealed a single band of SbH$_{2}$ with complex rotational structure in the 514.9 - 511.0 nm region. We find that the fluorescence lifetimes of the rotational transitions in this band are very short, of the order of 50-75 ns, suggesting an upper state dissociative process. The spectrum is assigned to the \~{A}$^{2}$A$_{1}$ - \~{X}$^{2}$B$_{1}$ electronic transition by analogy with the known spectra of NH$_{2}$, PH$_{2}$ and AsH$_{2}$ and in accord with a recent high level \textit{ab initio} study. Emission spectra obtained after laser excitation of single rotational lines in the 0-0 band show a ground state bending frequency of approx. 820 \wn , consistent with theoretical predictions. The rotationally resolved spectrum of the 0-0 band, which spans some 150 \wn , was recorded at a resolution of 0.08 \wn and analyzed in detail. The spectrum is complicated by large spin splittings and Sb hyperfine effects. The molecular constants were used to determine the geometry of SbH$_{2}$ in both states.

Publisher

International Symposium on Molecular Spectroscopy

Type of Resource

text

Language

eng

Permalink

http://hdl.handle.net/2142/104546

DOI

https://doi.org/10.15278/isms.2019.TD02

Copyright and License Information

Copyright 2019 Fumie X. Sunahori

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