Vibronic Ground State Rotational Spectrum of 3-Bromothiophene

1983 ◽  
Vol 38 (11) ◽  
pp. 1238-1247 ◽  
Author(s):  
Dirk Hübner ◽  
Eckhard Fliege ◽  
Dieter H. Sutter
Keyword(s):  
Ground State ◽  
Coupling Constants ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Set Up ◽  
Centrifugal Distortion Constants

The rotational spectrum of 3-bromothiophene was investigated in the frequency range between 8 and 18 GHz by use of a microwave Fourier transform spectrometer. Both a- and b-type spectra were assigned for the vibronic ground state. Rotational constants, quartic centrifugal distortion constants and quadrupole coupling constants were obtained for the 79Br- and 81Br-isotopic species. For the analysis, the effective rotational Hamiltonian including centrifugal distortion in the form of Van Eijck's symmetric top reduction and bromine quadrupole coupling was set up in the coupled basis of the limiting symmetric top, J, K, I, F, MF>, and was diagonalized numerically. Spin rotation interaction was neglected

The Centimeter and Millimeter Microwave Spectrum of 1,1-Difluoro-2-Chloroethylene

1993 ◽  
Vol 48 (3) ◽  
pp. 514-518 ◽  
Author(s):  
Luis A. Leal ◽  
J. C. López ◽  
J. L. Alonso ◽  
A. Guarnieri
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Coupling Analysis ◽  
Rotational Spectra ◽  
First Order ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants

Abstract The rotational spectra of both 35Cl and 37Cl 1,1-difluoro-2-chloroethylene isotopomers have been measured in the frequency range 12-225 GHz. A first order quadrupole coupling analysis has been performed for both isotopic species. The calculated quadrupole coupling constants for the 37Cl species not previously reported are χaa = - 49.2 (2), χbb = 14.2 (1), and χcc = 28.7 (1). Accurate rotational constants, quartic and some sextic centrifugal distortion constants have also been determined for both isotopomers from the fit to the observed central frequencies.

Terahertz Spectrum of Trioxane

1996 ◽  
Vol 51 (1-2) ◽  
pp. 123-128 ◽  
Author(s):  
H. Klein ◽  
S. P. Belov ◽  
G. Winnewisser
Keyword(s):  
Ground State ◽  
Rotational Constant ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Experimental Accuracy ◽  
Terahertz Spectrum ◽  
Vibrational Ground State ◽  
Isotopic Species ◽  
Centrifugal Distortion Constants

Abstract The pure rotational spectrum of trioxane, (H2CO)3 the trimer of formaldehyde, has been recorded with high resolution in the frequency range between 326 and 947 GHz for the main isotopomer, the 13 C, and the 18O isotopic species in the vibrational ground state. These new high J and K data reveal that the molecule is fairly rigid. For the constants determinable from the recorded high J and K spectra (J = 90 and K = 75) the rotational constant B = 5273.257 180(33) MHz,the two quartic centrifugal distortion constants DJ, and DJK, and the three sextic constants HJ, HJK, and HKJ are needed in the fit to reproduce the measured spectra within experimental accuracy. In addition, for the 13C isotopomer the sextic constants HJK and HKJ are determined as well as the off-diagonal parameters d1 and d2.

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.

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

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.

Mikrowellenspektrum und rotationsspektroskopische Konstanten der Methylchlorsilane: CH3SiH2Cl, CH3SiD2Cl und CD3SiD2Cl / Microwave Spectrum and Rotational Spectroscopic Constants of Methyl-chloro-silane: CH3SiH2Cl, CH3SiD2Cl and CD3SiD2Cl

1975 ◽  
Vol 30 (11) ◽  
pp. 1441-1446
Author(s):  
W. Zeil ◽  
W. Braun ◽  
B. Haas ◽  
H. Knehr ◽  
F. Rückert ◽  
...  
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

The microwave spectra of the following isotopic species of Methyl-chloro-silane: CH3SiH2Cl, CH3SiD2 and CD3SiD2Cl have been measured and the rotational spectroscopic constants (rotational constants, centrifugal distortion constants and nuclear quadrupole coupling constants) have been determined

Reanalysis of the Nuclear Quadrupole Coupling in the Rotational Spectrum of N-Methylpyrrole

1994 ◽  
Vol 49 (11) ◽  
pp. 1063-1066
Author(s):  
S. R. Huber ◽  
A. Bauder
Keyword(s):  
Fourier Transform ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Least Squares Fit ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants ◽  
Pulsed Nozzle ◽  
Measured Transition

Abstract The rotational spectrum of N-methylpyrrole has been measured with pulsed nozzle Fourier transform microwave spectrometers between 6 and 38 GHz. The quadrupole hyperfine structure due to 14N has been reanalyzed in the A (m = 0) state o f the methyl internal rotation. Improved rotational constants, centrifugal distortion constants, and quadrupole coupling constants have been simultaneously determined from the measured transition frequencies in an iterative least-squares fit.

Effects of Centrifugal Distortion and Nuclear Quadrupole Coupling in the Microwave Spectrum of Vinyl Chloride

1971 ◽  
Vol 49 (2) ◽  
pp. 255-264 ◽  
Author(s):  
M. C. L. Gerry
Keyword(s):  
Vinyl Chloride ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
First Order ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants ◽  
Infrared Data

Both a- and b-type rotational transitions have been measured up to J = 30 for the two most abundant isotopic species of vinyl chloride, in the frequency region 8–18 GHz. These have enabled refinement of the rotational and chlorine nuclear quadrupole coupling constants, and evaluation of all first order centrifugal distortion constants. From the quadrupole coupling constants it is concluded that the field gradient around the C—Cl bond is somewhat more symmetric than previously reported. A comparison is made between the centrifugal distortion constants obtained from the microwave spectrum and those calculated using infrared data.

Rotational Spectrum and 14N-Quadrupole Coupling Constants of Orthofluorobenzonitrile, a Microwave Fouriertransform Study

1986 ◽  
Vol 41 (7) ◽  
pp. 955-958 ◽  
Author(s):  
Olaf Böttcher ◽  
Dieter H. Sutter
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Vibrational State ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectrum ◽  
Frequency Range ◽  
Rotational Constants ◽  
Quadrupole Coupling

Seventyseven a-type rotational transitions of Orthofluorobenzonitrile were observed and assigned in the 8 - 25 GHz frequency range. The spectrum was recorded using the high resolution microwave Fourier transform spectrometer constructed at Kiel University. For most transitions the l4N quadrupole hfs patterns could be fully resolved. The spectroscopic constants obtained by a fit to the observed hfs-center frequencies and to the observed hfs multiplet splittings are: A = 2940.745(12) MHz, B = 1512.699(1) MHz, C = 998.633(1) MHz (rotational constants) and Χaa = - 4.114( 17) MHz, Xbb - Xcc= 0.383(34) MHz (14N quadrupole coupling constants). The rotational spectrum of a low lying vibrational state could be also assigned.

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.

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