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

1973 ◽  
Vol 28 (5) ◽  
pp. 729-738 ◽  
Author(s):  
J. Mjöberg ◽  
S. Ljunggren

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.

1987 ◽  
Vol 42 (2) ◽  
pp. 197-206 ◽  
Author(s):  
M. Meyer ◽  
U. Andresen ◽  
H. Dreizler

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.


1975 ◽  
Vol 30 (4) ◽  
pp. 541-548 ◽  
Author(s):  
P. J. Mjöberg ◽  
W. M. Ralowski ◽  
S. O. Ljunggren

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.


1975 ◽  
Vol 30 (11) ◽  
pp. 1441-1446
Author(s):  
W. Zeil ◽  
W. Braun ◽  
B. Haas ◽  
H. Knehr ◽  
F. Rückert ◽  
...  

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


1971 ◽  
Vol 49 (2) ◽  
pp. 255-264 ◽  
Author(s):  
M. C. L. Gerry

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.


1989 ◽  
Vol 44 (7) ◽  
pp. 669-674 ◽  
Author(s):  
N. Heineking ◽  
M.C.L. Gerry

Abstract The 14N nuclear quadrupole hyperfine structure in the rotational spectra of three isotopic species of methyl azide, CH3 14N3, CH3 15N14N2, and CH3 14N2 15N, has been resolved using microwave Fourier transform spectroscopy. The quadrupole coupling constants of 14N at all three positions have been evaluated and are compared with those from an ab initio calculation in the literature.Since the spectra of the substituted species have been obtained for the first time, they have provided new structural information: the rotational constants are consistent with a structure in which the NNN chain is slightly bent.


1993 ◽  
Vol 48 (3) ◽  
pp. 514-518 ◽  
Author(s):  
Luis A. Leal ◽  
J. C. López ◽  
J. L. Alonso ◽  
A. Guarnieri

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.


1987 ◽  
Vol 65 (10) ◽  
pp. 2478-2488 ◽  
Author(s):  
H. M. Jemson ◽  
W. Lewis-Bevan ◽  
M. C. L. Gerry

The microwave spectra of 79BrSCN and 81BrSCN have been measured and analysed to give rotational, centrifugal distortion, and Br quadrupole coupling constants. The molecule has been shown unambiguously to be BrSCN rather than BrNCS. A harmonic force field has been determined from combined vibrational and distortion data. With structural parameters for the SCN chain transferred from S(CN)2, both effective and ground state average values for the BrS length and BrSC angle have been estimated. The Br quadrupole tensor has been diagonalized, and the BrS bond is shown not to be bent.


Sign in / Sign up

Export Citation Format

Share Document