14N Quadrupole Coupling in the Rotational Spectrum of Ethyl Nitrite

1988 ◽  
Vol 43 (5) ◽  
pp. 469-475 ◽  
Author(s):  
Ch. Keussen ◽  
U. Andresen ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Isomers ◽  
Quantum Numbers ◽  
Quadrupole Coupling ◽  
Ethyl Nitrite

We investigated the 14N quadrupole coupling of three rotational isomers of ethyl nitrite in the ground state by microwave Fourier transform spectroscopy. Centrifugal distortion analyses were necessary to assign the transitions with high J quantum numbers. We found an additional splitting of some c-type transitions of the trans-gauche rotamer presumably arising from tunneling through the barrier separating the two equivalent gauche forms. This assumption could not be confirmed yet.

A Reinvestigation of the Rotational Spectrum of 2-Chloropropene

1983 ◽  
Vol 38 (11) ◽  
pp. 1231-1237 ◽  
Author(s):  
E. Fliege ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Microwave Spectrum ◽  
Rotational Spectrum ◽  
Isotopic Species ◽  
Quadrupole Coupling

The microwave spectrum of 2-chloropropene was reinvestigated using microwave Fourier transform spectroscopy. For the two isotopic species CH3C35Cl=CH2 and CH3C37Cl=CH2 the chlorine quadrupole coupling was determined with higher accuracy. The barrier to internal rotation was determined from the ground state. For comparison the first excited torsional state of CH3C35Cl=CH2 was remeasured and reanalysed

Nitrogen Quadrupole Coupling in the Rotational Spectrum of l-Isocyanoprop-2-yne, HC ≡ CCH2NC

1990 ◽  
Vol 45 (8) ◽  
pp. 986-988 ◽  
Author(s):  
M. Krüger ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Vibrational Ground State ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Hyperfine Splittings

AbstractThe rotational spectrum of l-isocyanoprop-2-yne, HC≡CCH2NC, has been measured in the vibrational ground state by microwave Fourier transform spectroscopy from 5 to 26.5 GHz. The nuclear quadrupole hyperfine splittings due to 14N have been analysed to obtain the coupling constants χaa = 290.3(78) kHz, χbb = 10.6(80) kHz and χcc= -300.9(80) kHz

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.

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.

scholarly journals Deuterium Quadrupole Coupling Constants of Deuterohalogenoacetylens

1988 ◽  
Vol 43 (8-9) ◽  
pp. 755-757 ◽  
Author(s):  
N. Heineking ◽  
M. Andolfatto ◽  
C. Kruse ◽  
W. Eberstein ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
High Resolution ◽  
Fourier Transform Spectroscopy ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Rotational Transitions

Abstract Employing the high resolution of microwave Fourier transform spectroscopy, we investigated the lowest rotational transitions of fluoro-, bromo-, and iodoacetylene-d. Along with the rotational, centrifugal distortion, halogen nuclear quadrupole, and halogen spin-rotation coupling constants, we determined the deuterium quadrupole coupling constants of bromo-and iodoacetylene-d. For fluoroacetylene-d, we redetermined the deuterium nuclear quadrupole coupling constants with higher accuracy.

Nuclear Quadrupole Hyperfine Structure in the Rotational Spectrum of 3-Chloropyridine. An Application of Microwave-Microwave Double Resonance Fourier Transform Spectroscopy

1988 ◽  
Vol 43 (7) ◽  
pp. 657-661 ◽  
Author(s):  
N. Heineking ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Double Resonance ◽  
Fourier Transform Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Modulation Technique ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

AbstractWe redetermined the rotational and the chlorine-35 and nitrogen-14 nuclear quadrupole coupling constants of 3-chloropyridine. The values are A = 5839.5330(12) MHz, B = 1604.1875(6) MHz, and C = 1258.3121 (5) MHz for the rotational constants, and χaa(Cl) = - 72.255(19) MHz, χbb(Cl) = + 38.500(13) MHz, χcc(Cl) = + 33.755(23) MHz and χaa(N) = - 0.009(13) MHz, χbb(N) = - 3.473(10) MHz, χCC(N) = + 3.482(16) MHz for the chlorine-35 and nitrogen-14 nuclear quadrupole coupling constants, respectively.Application of double resonance modulation technique is shown to greatly simplify the assign­ment of hyperfine structure components even of weak rotational transitions.

scholarly journals Rotational spectroscopy and astronomical search for glutaronitrile

2020 ◽  
Vol 636 ◽  
pp. A33
Author(s):  
C. Cabezas ◽  
C. Bermúdez ◽  
Y. Endo ◽  
B. Tercero ◽  
J. Cernicharo
Keyword(s):  
Fourier Transform ◽  
Supersonic Jet ◽  
Rotational Spectrum ◽  
Millimetre Wave ◽  
Quantum Numbers ◽  
Upper Limits ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants ◽  
High Level ◽  
Total Column

Context. Nitriles constitute almost 15% of the molecules observed in the interstellar medium (ISM), surprisingly only two dinitriles have been detected in the ISM so far. The lack of astronomical detections for dinitriles may be partly explained by the absence of laboratory rotational spectroscopic data. Aims. Our goal is to investigate the rotational spectrum of glutaronitrile, N≡C−CH2−CH2−CH2−C≡N, in order to allow its possible detection in the ISM. Methods. The rotational spectrum of glutaronitrile was measured using two different experimental setups. A Fourier transform microwave spectrometer was employed to observe the supersonic jet rotational spectrum of glutaronitrile between 6 and 20 GHz. In addition, the mmW spectrum was observed in the frequency range 72−116.5 GHz using a broadband millimetre-wave spectrometer based on radio astronomy receivers with fast Fourier transform backends. The spectral searches were supported by high-level ab initio calculations. Results. A total of 111 rotational transitions with maximum values of J and Ka quantum numbers 54 and 18, respectively, were measured for the gg conformer of glutaronitrile. The analysis allowed us to accurately determine the rotational, nuclear quadrupole coupling, quartic and sextic centrifugal distortion constants. These rotational parameters were employed to search for glutaronitrile in the cold and warm molecular clouds Orion KL, Sgr B2(N), B1-b and TMC-1, using the spectral surveys captured by IRAM 30 m at 3 mm. Glutaronitrile was not detected, and the upper limits’ column densities were derived. Those are a factor of 1.5 and 5 lower than those obtained for the total column densities of the analogous succinonitrile in Orion KL and Sgr B2, respectively.

scholarly journals Internal Rotation Analysis of the Ground State Microwave Spectrum of 2-Bromopropene

1984 ◽  
Vol 39 (7) ◽  
pp. 637-645
Author(s):  
E. Fliege ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Microwave Spectrum ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Methyl Rotation

The microwave spectrum of 2-bromopropene was reinvestigated with the use of microwave Fourier transform spectroscopy. For the two isotopic species CH3C79Br=CH2 and CH3C81Br=CH2 the bromine quadrupole coupling was determined with higher accuracy. The barrier hindering internal methyl rotation was obtained from the ground state.

scholarly journals Nuclear Quadrupole Coupling Effects in the Rotational Spectrum of 4-Cyanopyridine

1987 ◽  
Vol 42 (1) ◽  
pp. 83-86 ◽  
Author(s):  
Nils Heineking ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Substituent Effects ◽  
Fourier Transform Spectroscopy ◽  
Rotational Spectrum ◽  
Pyridine Derivatives ◽  
Coupling Effects ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

The quadrupole coupling of the two nitrogen nuclei was investigated by microwave Fourier transform spectroscopy. The results contribute to a comparison of substituent effects in different pyridine derivatives.

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