The pure rotational spectrum of the ScO (X2Σ+) radical

D. T. Halfen, J. Min, Lucy M Ziurys

Research output: Contribution to journalArticle

Abstract

The rotational spectrum of ScO (X2Σ+) has been measured in the gas phase in the frequency range 30–493 GHz using a combination of Fourier transform microwave/millimeter-wave (FTM/mmW) and submillimeter direct absorption methods. This work is the first pure rotational study of this radical. Both the ground vibrational and v = 1 states were observed. ScO was created from the reaction of metal vapor, produced either by a laser ablation source or a Broida-type oven, and N2O, in the former case heavily diluted in argon. Extensive hyperfine structure was observed in the FTM/mmW data, although the spin-rotation splitting was found to be small (∼3 MHz). In the mm-wave spectra, however, the fine and hyperfine structure was blended together, resulting in broad, single lines for a given transition N + 1 ← N. The data were analyzed in a combined fit using the very accurate hyperfine measurements of Childs and Steimle (1988), employing a Hund's case b Hamiltonian, and an improved set of rotational and centrifugal distortion constants were determined. These measurements improve the accuracy of predicted frequencies for astronomical searches by 14–18 MHz, or 16–20 km/s, in the 1 mm region – a difference of half to a full linewidth for certain interstellar sources. This work also demonstrates the capabilities of the FTM/mmW spectrometer at 61 GHz.

Original languageEnglish (US)
Pages (from-to)1-5
Number of pages5
JournalJournal of Molecular Spectroscopy
Volume331
DOIs
StatePublished - Jan 1 2017

Fingerprint

rotational spectra
Millimeter waves
millimeter waves
Fourier transforms
Microwaves
hyperfine structure
microwaves
Hamiltonians
metal vapors
Argon
ovens
Ovens
Laser ablation
Linewidth
laser ablation
Spectrometers
Gases
frequency ranges
Metals
fine structure

Keywords

  • FTM/mmW spectroscopy
  • Laser ablation
  • Millimeter/submillimeter direct absorption spectroscopy
  • Rotational spectroscopy
  • Scandium oxide (ScO)

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Spectroscopy
  • Physical and Theoretical Chemistry

Cite this

The pure rotational spectrum of the ScO (X2Σ+) radical. / Halfen, D. T.; Min, J.; Ziurys, Lucy M.

In: Journal of Molecular Spectroscopy, Vol. 331, 01.01.2017, p. 1-5.

Research output: Contribution to journalArticle

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