TY - JOUR
T1 - The ground state of KO revisited
T2 - The millimeter and submillimeter spectrum of potassium oxide
AU - Burton, Mark A.
AU - Russ, Benjamin T.
AU - Bucchino, Matthew P.
AU - Sheridan, Phillip M.
AU - Ziurys, Lucy M.
N1 - Funding Information:
This work was supported by NSF grants AST-1515568 and CHE-1565765. BTR and PMS would like to thank Canisius College for travel funds and the Ziurys group for their hospitality.
Publisher Copyright:
© 2019 the Owner Societies.
PY - 2019
Y1 - 2019
N2 - The millimeter/sub-millimeter spectrum of the KO radical has been recorded in the frequency range 90-534 GHz using direct absorption methods. The radical was synthesized by reacting potassium vapor, produced with a Broida-type oven, with either N2O or O2 mixed in argon carrier gas. Twenty-seven rotational transitions of KO were measured, each exhibiting a doublet structure with a relatively small splitting (∼100-200 MHz) that increased noticeably with frequency. A perturbation was apparent in the rotational lines at energies above ∼120 cm-1, which was more prominent in one doublet component. The data were successfully fit with a Hund's case (c) Hamiltonian, assuming that spectra arise from a 2Πi state, and rotational and effective lambda-doubling constants were determined. Higher order centrifugal distortion terms were needed to account for the perturbation. The spectra could also be fit as a 2Σ+ ground state, but less successfully, and the resulting rotational constant of B = 8235.4 MHz disagreed significantly with that predicted by theory. On the basis of the experimental data, the ground electronic state of KO has been assigned as 2Πi, although the 2Σ+ assignment cannot be entirely ruled out.
AB - The millimeter/sub-millimeter spectrum of the KO radical has been recorded in the frequency range 90-534 GHz using direct absorption methods. The radical was synthesized by reacting potassium vapor, produced with a Broida-type oven, with either N2O or O2 mixed in argon carrier gas. Twenty-seven rotational transitions of KO were measured, each exhibiting a doublet structure with a relatively small splitting (∼100-200 MHz) that increased noticeably with frequency. A perturbation was apparent in the rotational lines at energies above ∼120 cm-1, which was more prominent in one doublet component. The data were successfully fit with a Hund's case (c) Hamiltonian, assuming that spectra arise from a 2Πi state, and rotational and effective lambda-doubling constants were determined. Higher order centrifugal distortion terms were needed to account for the perturbation. The spectra could also be fit as a 2Σ+ ground state, but less successfully, and the resulting rotational constant of B = 8235.4 MHz disagreed significantly with that predicted by theory. On the basis of the experimental data, the ground electronic state of KO has been assigned as 2Πi, although the 2Σ+ assignment cannot be entirely ruled out.
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U2 - 10.1039/c9cp03465j
DO - 10.1039/c9cp03465j
M3 - Article
C2 - 31552946
AN - SCOPUS:85073125582
SN - 1463-9076
VL - 21
SP - 21960
EP - 21965
JO - Physical Chemistry Chemical Physics
JF - Physical Chemistry Chemical Physics
IS - 39
ER -