Hyperfine Structure in the Rotational Spectrum of tert-Butyl Bromide

1990 ◽  
Vol 45 (6) ◽  
pp. 807-810 ◽  
Author(s):  
H. Harder ◽  
W. Stahl ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Butyl Bromide ◽  
Rotational Spectra ◽  
Tert Butyl ◽  
Quadrupole Coupling

AbstractWe reinvestigated the rotational spectra of tert-butyl bromide (CH3)3C79Br and (CH3)3C81Br, with the high precision of microwave Fourier transform spectroscopy. The rotational and quadrupole coupling constants were improved, the centrifugal distortion and bromine spin-rotation constants were determined

Rotational Spectrum of Aminoborane: Centrifugal Distortion Constants and Boron and Nitrogen Hyperfine Structure

1991 ◽  
Vol 46 (9) ◽  
pp. 770-776 ◽  
Author(s):  
Kirsten Vormann ◽  
Helmut Dreizler ◽  
Jens Doose ◽  
Antonio Guarnieri
Keyword(s):  
Hyperfine Structure ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Wave Region ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

AbstractThe boron and nitrogen hyperfine structure in the rotational spectra of two aminoborane isotopomers, 11 BH2NH2 and 10BH2NH2, has been investigated and the quadrupole coupling constants of boron 10B, 11B and nitrogen 14N have been determined. We get the following results for the nuclear quadrupole coupling constants: χaa(11B) = -1.684 (14) MHz, χbb(11B) = -2.212 (11) MHz, χcc(11B) = 3.896(11) MHz, χaa(10B) = -3.481 (11) MHz, χbb(10B) = -4.623 (14) MHz, χCC(10B) = 8.104 (14) MHz and xaa(14N) = 0.095 (9) MHz, χbb(14N) = 2.091 (8) MHz, χcf4 (14N)=-2.186 (8) MHz. These nitrogen quadrupole coupling constants are those of the 11BH2 NH2 isotopomer. Additionally we were able to determine two out of the three spin rotation coupling constants caa, cbb, and ccc of boron, caa(11 B = 55.2 (26) kHz, cbb(11B) = 6.62 (36) kHz, caa (10B) = 15.26 (69) kHz and cbb(10B) = 4.94 (70) kHz. The spin rotation coupling constants ccc had to be fixed to zero in both cases. Furthermore we measured the rotational spectra in the mm-wave region to determine all quartic and several sextic centrifugal distortion constants according to Watson's A and S reduction

33S Nuclear Hyperfine Structure in the Rotational Spectrum of Thiazole

1993 ◽  
Vol 48 (12) ◽  
pp. 1219-1222 ◽  
Author(s):  
U. Kretschmer ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Molecular Beam ◽  
Microwave Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract We investigated the 33S nuclear quadrupole coupling of thiazole- 33S in natural abundance by molecular beam Fourier transform microwave spectroscopy. In addition the 14N nuclear quadrupole coupling could be analyzed with high precision. We derived the rotational constants A = 8529.29268 (70) MHz, B = 5427.47098 MHz, and C = 3315.21676 (26) MHz, quartic centrifugal distortion constants and the quadrupole coupling constants of 33S χaa = 7.1708 (61) MHz and χbb= -26.1749 (69) MHz and of 14N χ aa = -2.7411 (61) MHz and χbb = 0.0767 (69) MHz.

14N-and D-Hyperfine Structure in the Rotational Spectrum of Pyrrolidine

1989 ◽  
Vol 44 (9) ◽  
pp. 837-840
Author(s):  
H. Ehrlichmann ◽  
J.-U. Grabow ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra

Abstract We present an analysis of the rotational spectra of the normal and the N-deuterated pyrrolidine measured by microwave Fourier transform spectroscopy. The quartic centrifugal distortion con­ stants and the 14N coupling constants have been determined with higher accuracy. In addition the D hyperfine structure could be analyzed.

Boron and Nitrogen Hyperfine Structure in the Rotational Spectrum of Aminodifluoroborane

1991 ◽  
Vol 46 (10) ◽  
pp. 909-913
Author(s):  
◽  
Helmut Dreizler
Keyword(s):  
Hyperfine Structure ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

AbstractThe boron and nitrogen hyperfine structure in the rotational spectra of aminodifluoroborane has been investigated and the quadrupole coupling constants of 11B and nitrogen have been determined. We get the following results for the nuclear quadrupole coupling constants: Χaa(11B) = - 1.971 (6) MHz, Xbb(11B) = 0.500(11) MHz, Xcc(11B) - 2.471 (11) MHz, and Xaa(14N) = 0.890 (5) MHz, Xbb(14N) = 2.303 (7) MHz, Xcc(14N) = - 3.193 (8) MHz. Additionally we determined rotational and centrifugal distortion constants according to Watson's A reduction.

Nitrogen Quadrupole Hyperfine Structure in the Rotational Spectrum of 2-,3-,and 4-Fluoro-Benzonitrile.A Comparative High Resolution Microwave Fourier Transform Study

1988 ◽  
Vol 43 (1) ◽  
pp. 47-58 ◽  
Author(s):  
Olaf Böttcher ◽  
Dieter H. Sutter
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Hyperfine Structure ◽  
Experimental Technique ◽  
Cylindrical Symmetry ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Distortion Parameters

Abstract A microwave Fourier transform study of the rotational spectrum of 3-fluoro-benzonitrile was carried out to study the 14N quadrupole coupling and to give improved rotational constants and centrifugal distortion parameters. In order to fully exploit the high resolution inherent to the experimental technique, frequencies, linewidths, intensities and phases were directly fitted to the observed transient emission signals. The quadrupole coupling constants are discussed in comparison to those of the related molecules 2-fluoro-benzonitrile, 4-fluoro-benzonitrile, and benzonitrile itself. For this comparison a sufficient number of hfs-patterns of the latter molecules was remeasured to derive coupling constants of comparable reliability. The four molecules may be grouped into two pairs. In benzonitrile and in 3-fluoro-benzonitrile the CN-bond shows a smaller deviation from cylindrical symmetry than in 2-and 4-fluoro-benzonitrile.

Nitrogen and Deuterium Hyperfine Structure in the Rotational Spectrum of Morpholine

1989 ◽  
Vol 44 (9) ◽  
pp. 833-836 ◽  
Author(s):  
J.-U. Grabow ◽  
H. Ehrlichmann ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Rotational Spectra ◽  
Quadrupole Coupling

Abstract We reinvestigated the rotational spectra of morpholine and N-deutero morpholine with the higher precision of microwave Fourier transform spectroscopy. The rotational, centrifugal, and nitrogen quadrupole coupling constants were improved and the deuterium quadrupole coupling constants determined.

Nitrogen and Deuterium Hyperfine Structure in the Rotational Spectrum of Piperidine

1989 ◽  
Vol 44 (9) ◽  
pp. 841-847 ◽  
Author(s):  
H. Ehrlichmann ◽  
J.-U. Grabow ◽  
H. Dreizler ◽  
N. Heineking ◽  
M. Andolfatto
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Rotational Spectra ◽  
Coupling Tensor ◽  
Quadrupole Coupling

Abstract We reinvestigated by microwave Fourier transform spectroscopy the rotational spectra of the axial and equatorial isotopomers of piperidine and N-deutero piperidine. The rotational, centrifugal, and nitrogen quadrupole coupling constants were improved, the deuterium quadrupole coupling constants were determined. The principal coupling tensor elements for nitrogen were estimated.

The 33S Nuclear Hyperfine Structure in the Rotational Spectrum of Isothiazole

1994 ◽  
Vol 49 (11) ◽  
pp. 1059-1062
Author(s):  
J. Gripp ◽  
U. Kretschmer ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Molecular Beam ◽  
Microwave Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract We investigated the 33S nuclear quadrupole coupling in the rotational spectrum of isothiazole in natural abundance by molecular beam Fourier transform microwave spectroscopy. In addition the 14N nuclear quadrupole coupling could be analyzed with high precision. We derived the rotational constants A = 8275.51880(80) MHz, B = 5767.06181 (40) MHz, and C = 3396.85702(36) MHz, quartic centrifugal distortion constants, and the quadrupole coupling constants χaa (33S) = 8.7015 (57) MHz, χbb(33S) = -32.9696(60) MHz, χaa(14N) = 1.0732(47) MHz and χbb(14N) = -2.4753(46) MHz.

Investigation of the Microwave Spectrum of Cyclopropyl Isocyanate. An Example for the Failure of Centrifugal Distortion Theory

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1175-1184 ◽  
Author(s):  
C. Heldmann ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Ground State ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Vibrational Ground State ◽  
Quadrupole Coupling

Abstract The vibrational ground state microwave spectrum of cyclopropyl isocyanate was investigated in the region from 8.4 to 40 GHz by microwave Fourier transform (MWFT) spectroscopy. The quadru-pole hyperfine structure was resolved and assigned. The quadrupole coupling constants are given. With respect to the data given in the literature up to now, this work led to a more profound description of the pure rotational spectrum. Furthermore, some interesting and surprising results concerning the effect of centrifugal distortion are presented. Compared to hitherto existing investi-gations, these results indicate a more complicated conformational behaviour of cyclopropyl iso-cyanate.

14N Nuclear Quadrupole Hyperfine Structure in the Rotational Spectrum of Thionyl Aniline

1991 ◽  
Vol 46 (11) ◽  
pp. 989-992 ◽  
Author(s):  
N. Heineking ◽  
J.-U. Grabow ◽  
K. Vormann ◽  
W. Stahl
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Molecular Beam ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants ◽  
Hyperfine Structures

AbstractNuclear quadrupole hyperfine structures have been resolved in the rotational spectrum of thionyl aniline, C6H5NSO, using pulsed molecular beam microwave Fourier transform spectroscopy. High precision nuclear quadrupole coupling constants, rotational and quartic centrifugal distortion constants have been determined from the analysis of 12 low-J transitions. Coupling constants are χaa = + 1.5730(14) MHz and (χbb - χcc)= -5.6499(13) MHz. rotational constants are A-4026.72i5(4) MHz, B = 860.64732(8) MHz, and C = 709.52027(7) MHz, and centrifugal distortion constants are ΔJ - 36.6(5) Hz, ΔJK= -107.5(20) Hz, ΔK = 703(68) Hz, δJ = 8.1(5) Hz, and δK=111(19) Hz (representation I' used).

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