The microwave spectrum of 2-methylthiazole: Methyl internal rotation and 14N nuclear quadrupole coupling

Research output: Contribution to journal › Article › Research › peer review

Authors

  • J. U. Grabow
  • H. Hartwig
  • N. Heineking
  • W. Jäger
  • H. Mäder
  • H. W. Nicolaisen
  • W. Stahl

External Research Organisations

  • Kiel University
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Details

Original languageEnglish
Pages (from-to)349-356
Number of pages8
JournalJournal of molecular structure
Volume612
Issue number2-3
Early online date28 May 2002
Publication statusPublished - 17 Jul 2002
Externally publishedYes

Abstract

The microwave spectrum of 2-methylthiazole has been investigated in the frequency range from 7 to 13 GHz. Rotational spectra in the two lowest states of internal methyl rotation (m = 0, ± 1) were measured using a pulsed molecular beam Fourier transform microwave spectrometer. The analysis of the spectra was based on a rigid frame-rigid symmetric top Hamiltonian with inclusion of first order energy contributions from 14N-nuclear quadrupole coupling, yielding the rotational constants A = 5343.883(74) MHz, B = 3265.914(54) MHz, C = 2052.252(51) MHz, the threefold barrier to internal rotation V3 = 34.938(20)cm-1, the moment of inertia of the methyl group Iα = 3.1651(20) uÅ2, the angle between internal rotor axis i and inertial a-axis ∠(i, a) = 4.462(1)°, and the nitrogen quadrupole coupling constants X+ = Xbb + Xcc = -0.5239(15) MHz, X- = Xbb- Xcc = -5.3030(25) MHz and |Xab| = 2.2791(137) MHz. The results from this investigation are compared with results from previous microwave studies on 4- and 5-methylthiazole and 2-, 4- and 5-methyloxazole.

Keywords

    2-Methylthiazole, N-quadrupole coupling, Fourier transform microwave spectroscopy, Methyl internal rotation, Rotational spectra

ASJC Scopus subject areas

Cite this

The microwave spectrum of 2-methylthiazole: Methyl internal rotation and 14N nuclear quadrupole coupling. / Grabow, J. U.; Hartwig, H.; Heineking, N. et al.
In: Journal of molecular structure, Vol. 612, No. 2-3, 17.07.2002, p. 349-356.

Research output: Contribution to journal › Article › Research › peer review

Grabow, JU, Hartwig, H, Heineking, N, Jäger, W, Mäder, H, Nicolaisen, HW & Stahl, W 2002, 'The microwave spectrum of 2-methylthiazole: Methyl internal rotation and 14N nuclear quadrupole coupling', Journal of molecular structure, vol. 612, no. 2-3, pp. 349-356. https://doi.org/10.1016/S0022-2860(02)00144-8
Grabow, J. U., Hartwig, H., Heineking, N., Jäger, W., Mäder, H., Nicolaisen, H. W., & Stahl, W. (2002). The microwave spectrum of 2-methylthiazole: Methyl internal rotation and 14N nuclear quadrupole coupling. Journal of molecular structure, 612(2-3), 349-356. https://doi.org/10.1016/S0022-2860(02)00144-8
Grabow JU, Hartwig H, Heineking N, Jäger W, Mäder H, Nicolaisen HW et al. The microwave spectrum of 2-methylthiazole: Methyl internal rotation and 14N nuclear quadrupole coupling. Journal of molecular structure. 2002 Jul 17;612(2-3):349-356. Epub 2002 May 28. doi: 10.1016/S0022-2860(02)00144-8
Grabow, J. U. ; Hartwig, H. ; Heineking, N. et al. / The microwave spectrum of 2-methylthiazole : Methyl internal rotation and 14N nuclear quadrupole coupling. In: Journal of molecular structure. 2002 ; Vol. 612, No. 2-3. pp. 349-356.
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title = "The microwave spectrum of 2-methylthiazole: Methyl internal rotation and 14N nuclear quadrupole coupling",
abstract = "The microwave spectrum of 2-methylthiazole has been investigated in the frequency range from 7 to 13 GHz. Rotational spectra in the two lowest states of internal methyl rotation (m = 0, ± 1) were measured using a pulsed molecular beam Fourier transform microwave spectrometer. The analysis of the spectra was based on a rigid frame-rigid symmetric top Hamiltonian with inclusion of first order energy contributions from 14N-nuclear quadrupole coupling, yielding the rotational constants A = 5343.883(74) MHz, B = 3265.914(54) MHz, C = 2052.252(51) MHz, the threefold barrier to internal rotation V3 = 34.938(20)cm-1, the moment of inertia of the methyl group Iα = 3.1651(20) u{\AA}2, the angle between internal rotor axis i and inertial a-axis ∠(i, a) = 4.462(1)°, and the nitrogen quadrupole coupling constants X+ = Xbb + Xcc = -0.5239(15) MHz, X- = Xbb- Xcc = -5.3030(25) MHz and |Xab| = 2.2791(137) MHz. The results from this investigation are compared with results from previous microwave studies on 4- and 5-methylthiazole and 2-, 4- and 5-methyloxazole.",
keywords = "2-Methylthiazole, N-quadrupole coupling, Fourier transform microwave spectroscopy, Methyl internal rotation, Rotational spectra",
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Download

TY - JOUR

T1 - The microwave spectrum of 2-methylthiazole

T2 - Methyl internal rotation and 14N nuclear quadrupole coupling

AU - Grabow, J. U.

AU - Hartwig, H.

AU - Heineking, N.

AU - Jäger, W.

AU - Mäder, H.

AU - Nicolaisen, H. W.

AU - Stahl, W.

N1 - Funding Information: The authors thank the Deutsche Forschungsgemeinschaft, the Fonds der Chemie, and the Land Schleswig-Holstein for funds.

PY - 2002/7/17

Y1 - 2002/7/17

N2 - The microwave spectrum of 2-methylthiazole has been investigated in the frequency range from 7 to 13 GHz. Rotational spectra in the two lowest states of internal methyl rotation (m = 0, ± 1) were measured using a pulsed molecular beam Fourier transform microwave spectrometer. The analysis of the spectra was based on a rigid frame-rigid symmetric top Hamiltonian with inclusion of first order energy contributions from 14N-nuclear quadrupole coupling, yielding the rotational constants A = 5343.883(74) MHz, B = 3265.914(54) MHz, C = 2052.252(51) MHz, the threefold barrier to internal rotation V3 = 34.938(20)cm-1, the moment of inertia of the methyl group Iα = 3.1651(20) uÅ2, the angle between internal rotor axis i and inertial a-axis ∠(i, a) = 4.462(1)°, and the nitrogen quadrupole coupling constants X+ = Xbb + Xcc = -0.5239(15) MHz, X- = Xbb- Xcc = -5.3030(25) MHz and |Xab| = 2.2791(137) MHz. The results from this investigation are compared with results from previous microwave studies on 4- and 5-methylthiazole and 2-, 4- and 5-methyloxazole.

AB - The microwave spectrum of 2-methylthiazole has been investigated in the frequency range from 7 to 13 GHz. Rotational spectra in the two lowest states of internal methyl rotation (m = 0, ± 1) were measured using a pulsed molecular beam Fourier transform microwave spectrometer. The analysis of the spectra was based on a rigid frame-rigid symmetric top Hamiltonian with inclusion of first order energy contributions from 14N-nuclear quadrupole coupling, yielding the rotational constants A = 5343.883(74) MHz, B = 3265.914(54) MHz, C = 2052.252(51) MHz, the threefold barrier to internal rotation V3 = 34.938(20)cm-1, the moment of inertia of the methyl group Iα = 3.1651(20) uÅ2, the angle between internal rotor axis i and inertial a-axis ∠(i, a) = 4.462(1)°, and the nitrogen quadrupole coupling constants X+ = Xbb + Xcc = -0.5239(15) MHz, X- = Xbb- Xcc = -5.3030(25) MHz and |Xab| = 2.2791(137) MHz. The results from this investigation are compared with results from previous microwave studies on 4- and 5-methylthiazole and 2-, 4- and 5-methyloxazole.

KW - 2-Methylthiazole

KW - N-quadrupole coupling

KW - Fourier transform microwave spectroscopy

KW - Methyl internal rotation

KW - Rotational spectra

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U2 - 10.1016/S0022-2860(02)00144-8

DO - 10.1016/S0022-2860(02)00144-8

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AN - SCOPUS:0037125438

VL - 612

SP - 349

EP - 356

JO - Journal of molecular structure

JF - Journal of molecular structure

SN - 0022-2860

IS - 2-3

ER -