scholarly journals Microwave Spectrum and Quadrupole Coupling Constants of 2-Bromothiophene

1975 ◽  
Vol 30 (4) ◽  
pp. 541-548 ◽  
Author(s):  
P. J. Mjöberg ◽  
W. M. Ralowski ◽  
S. O. Ljunggren
Keyword(s):  
Ground State ◽  
Second Order ◽  
Coupling Constants ◽  
Order Perturbation ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Isotopic Species ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Hyperfine Splittings

Abstract The microwave spectra of the two 79Br and 81Br isotopic species of 2-bromothiophene have been measured in the region 18000-40000 MHz.For both isotopic species, the rotational constants of the ground state and one vibrationally excited state were determined, as well as the centrifugal distortion coefficients of the ground state. The ground state rotational constants in MHz are as follows:C4H332S79Br C4H332S81BrA = 5403.432 ±0.111 5403.563 ±0.095,B = 1139.0689±0.0010 1126.5173±0.0011 C = 940.5142±0.0018 931.9315±0.0009.In order to perform a second-order perturbation treatment of the quadrupole interaction, the matrix elements of products of direction cosines in terms of the symmetric top wave functions have been derived. By the first-and second-order perturbation analysis of the hyperfine splittings of the rotational lines, the nuclear quadrupole coupling constants have been determined. The values in MHz areXaa = 592.7 ±1.5 493.7 ±1.5,Xbb = -295.3 ±0.6 -245.6 ±0.7, Xcc = -297.4 ±1.6 -248.1 ±1.6,Xab = 80 ±9 64±8 ,in the principal axes system of the molecule.

scholarly journals Microwave Spectrum and Quadrupole Coupling Constants of 2-Chlorothiophene

1973 ◽  
Vol 28 (5) ◽  
pp. 729-738 ◽  
Author(s):  
J. Mjöberg ◽  
S. Ljunggren
Keyword(s):  
Ground State ◽  
Hyperfine Splitting ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Vibrationally Excited ◽  
Isotopic Species ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

The microwave spectra of the two chlorine isotopic species of 2-chlorothiophene have been measured in the region 26 500 - 40 000 MHz.For both isotopic species, the rotational constants of the ground state and one vibrationally excited state were determined, as well as the centrifugal distortion coefficients of the ground state.From the hyperfine splitting of the rotational lines, the nuclear quadrupole coupling constants were calculated. The values in MHz are for 35Cl:and for 37Cl: χaa= -74.77 ±0.05, χbb=37.51 ± 0.17, χcc=37.25 ± 0.18 χaa= -58.98 ±0.09, χbb=29.55 ± 0.26, χcc=29.43 ± 0.28in the principal-axes system of the molecule.

Microwave Spectrum and Nuclear Quadrupole Coupling of 2-Chloropyridine

1987 ◽  
Vol 42 (2) ◽  
pp. 197-206 ◽  
Author(s):  
M. Meyer ◽  
U. Andresen ◽  
H. Dreizler
Keyword(s):  
Excited State ◽  
Ground State ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Vibrationally Excited ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Mo Theory

The microwave spectrum of 2-chloropyridine, 2-Cl(C5H4N), has been studied to determine the 35Cl, 37Cl and 14N nuclear quadrupole coupling constants. The results are discussed within a simple MO theory. We propose an approximate r0-structure under certain assumptions. In addition to the ground state we observed one vibrationally excited state of both chlorine isotopic species of 2-chloropyridine.

Microwave Spectrum of Mono-deuterated Acetyl Cyanide CH2DCOCN and Complete rs- and r0-structure of Acetyl Cyanide

1977 ◽  
Vol 32 (11) ◽  
pp. 1301-1308 ◽  
Author(s):  
G. K. Pandey ◽  
M. Andolfatto ◽  
H. Dreizler
Keyword(s):  
Double Resonance ◽  
Coupling Constants ◽  
Rotational Constants ◽  
Rigid Rotator ◽  
Methyl Group ◽  
Isotopic Species ◽  
Accuracy Of Measurements ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Hyperfine Splittings

Abstract Microwave spectra of symmetric and asymmetric forms of monodeuterated acetyl cyanide CH2DCOCN have been observed and measured. Significant differences occur between our assign­ment and those of Krisher and Wilson1. We have confirmed all our assignments with the help of microwave - microwave double resonance (MW-MW-DR) experiments. By fitting about twelve low J transition frequencies to a rigid rotator, accurate values for the rotational constants have been obtained. From the analysis of the quadrupole hyperfine splittings of some of the tran­sitions, the nuclear quadrupole coupling constants are also determined. Using the measured rotational constants for a number of molecular isotopic species of Refer­ence (1), and in addition those measured in this laboratory for the 15N, monodeuterated and normal species (determined with greater accuracy), a complete rs-and ro-structure has been calculated. The important conclusions are - i) the methyl group does not possess C3V symmetry and ii) the Ccarbonyl, - Ccyanide and C - N bonds are collinear within the accuracy of measurements.

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

Microwave Spectrum of Chloroacetylene in Ground and Excited Vibrational States

1978 ◽  
Vol 33 (2) ◽  
pp. 156-163 ◽  
Author(s):  
Harold Jones ◽  
Michio Takami ◽  
John Sheridan
Keyword(s):  
Excited States ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Frequency Range ◽  
Vibrational States ◽  
Vibrationally Excited ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Quadrupole Coupling

The microwave spectrum of chloroacetylene in the ground and excited states has been investigated in the frequency range 15 to 306 GHz. Ground state rotational and nuclear quadrupole coupling constants for twelve isotopic species of chloroacetylene and accurate distortion constants were determined for two of these. The data allowed the rs-structure of chloroacetylene to be reconsidered and the internal consistency of this method of structure determination to be checked. Rotational spectra in five vibrationally excited states, with energy up to 700 cm-1 were observed for four different isotopic species and spectroscopic constants for these states were derived.

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

Mikrowellenspektrum, Rotationskonstanten, Zentrifugalverzerrungskonstanten und Kernquadrupolkopplungskonstanten des CD3SiH2Cl. Über Bindungseigenschaften in Silicium-Halogeniden: 1. Mitteilung / Microwave spectrum, rotational constants, centrifugaldistortion constants and nuclear quadrupole coupling constants of CD3SiH2Cl

1972 ◽  
Vol 27 (7) ◽  
pp. 1150-1159 ◽  
Author(s):  
Werner Zeil ◽  
Richard Gegenheimer ◽  
Saskia Pferrer ◽  
Marwan Dakkouri
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole

Abstract Microwave The microwave spectra of the following isotopic species of methylchloro-silane CD328SiH235Cl, CD329SiH235Cl, CD330SiH235Cl, CD328SiH237Cl have been measured and analyzed. The rotational constants, centrifugaldistortion constants and nuclear quadrupole coupling constants have been determined. The Si-Cl-distance is 2.049 Å respectively 2.052 Å as calculated by the rs method. The corresponding angles between the siliconchlorine-bond and the inertia-axis a are Θ = 26°53' respectively 26°49'

The microwave spectrum and molecular structure of trimethylene sulphoxide; bends, tilts and twists in the methylene groups

1977 ◽  
Vol 354 (1679) ◽  
pp. 491-509 ◽  
Keyword(s):  
Excited States ◽  
Ground State ◽  
Rotational Spectrum ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Vibrational Ground State ◽  
Isotopic Species ◽  
Microwave Rotational Spectrum ◽  
Methylene Groups ◽  
The Common

The microwave rotational spectrum of the common isotopic species ( 12 CH 2 ) 32 3 S 16 O of trimethylene sulphoxide has been assigned and rotational constants obtained for the vibrational ground state, the first four excited states of the ring puckering mode and two other low-lying vibrationally excited states. In addition rotational constants have been derived for the vibrational ground state of each of the eight different singly substituted isotopic species [ 34 S], [ 13 C 2 ], [13 C 3 ], [ 2 H 2 ], [ 2 H 2 .], [ 2 H 3 ], [ 2 H 3 .] and [ 18 O], with the first three in natural abundance, and are as follows:

Zum Mikrowellenspektrum des Pyridazins

1967 ◽  
Vol 22 (4) ◽  
pp. 531-543 ◽  
Author(s):  
W. Werner ◽  
H. Dreizler ◽  
H. D. Rudolph
Keyword(s):  
Ground State ◽  
Stark Effect ◽  
Coupling Constants ◽  
Isotopic Substitution ◽  
Rotational Spectrum ◽  
Coupling Tensor ◽  
Vibrational Ground State ◽  
Principal Axes ◽  
Quadrupole Coupling ◽  
Tensor Element

The rotational spectrum of pyridazine in the vibrational ground state is reported for the parent species and three isotopically substituted species. The rs coordinates of the ring atoms have been reliably determined with the exception of the α coordinate of the Cl and the C4 atoms which is obviously too small for the application of KRAITCHMAN’S equations. The dipole moment was calculated from the STARK effect as μα=4.22 D. The quadrupole coupling constants, from hfs measurements, are χαα=— 4.64, χbb=1.38, χcc=3.27 MHz. The only non-diagonal quadrupole coupling tensor element has been less accurately determined from the variation of the hfs upon rotation of the principal axes system by isotopic substitution of one N15 nucleus.

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

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