Ground state spectroscopic constants and electric dipole moment of D14N12C32S from its microwave and millimetre wave spectra

1978 ◽  
Vol 56 (10) ◽  
pp. 1297-1307 ◽  
Author(s):  
L. B. Szalanski ◽  
M. C. L. Gerry ◽  
G. Winnewisser ◽  
K. Yamada ◽  
M. Winnewisser
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Wave Spectra ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants ◽  
First Time

The microwave and millimetre wave spectra of D14N12C32S in its ground vibrational state have been investigated in the frequency region 8–210 GHz. A large number of a-type Q branch and b-type P and R branch transitions up to J = 62 have been assigned and measured for the first time. Their frequencies have been combined with those of the a-type R branches up to K = 5 in an analysis for rotational, centrifugal distortion, and 14N quadrupole coupling constants. Constants obtained, in Watson's S reduction formalism, are: rotational constants in megahertz: A0 = 705 511(370); B0 = 5500.4391(15); C0 = 5445.2252(15); quartic centrifugal distortion constants in kilohertz: Dj = 1.0926(25); Djk = 1333.4(12); d1 = 3.455(5) × 10−2d2 = −7.8(14) × 10−3; 14N quadrupole coupling constants in megahertz: χaa = 1.19(6), χbb−χcc <0.05. The b-component of the dipole moment, μb, has been measured using the Stark effect as 1.08(15) D; this, when combined with μa = 1.67(3) D gives a total dipole moment of 1.99(15) D, essentially parallel to the HN bond.

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

The Microwave and Millimetre Wave Spectrum, Molecular Constants, Dipole Moment, and Structure of Isocyanic Acid, HNCO

1975 ◽  
Vol 53 (19) ◽  
pp. 1869-1901 ◽  
Author(s):  
W. H. Hocking ◽  
M. C. L. Gerry ◽  
Gisbert Winnewisser
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Wave Spectrum ◽  
Rotational Constant ◽  
Isocyanic Acid ◽  
Centrifugal Distortion ◽  
Molecular Constants ◽  
Millimetre Wave ◽  
Order Of Magnitude ◽  
First Time

The microwave and millimetre wave spectra of six isotopic species of isocyanic acid, HNCO, have been measured. The molecule is a very slightly asymmetric prolate rotor. Besides the a type R branches, previously reported for two species, we have assigned for the first time a type Q branches and also some intense b type P and R branch transitions. Accurate values of the rotational constants have been determined. The rotational constant A0 is particularly large, with the result that the molecule undergoes very large centrifugal distortion, and terms up to the 12th power in the angular momentum are required to fit the spectrum. 14N nuclear quadrupole hyperfine splitting has been measured and accurate values for both χaa and (χbb − χcc) have been obtained, the latter for the first time. From the Stark effect of the b type transitions we have found the b component of the dipole moment to be 1.35 ± 0.1 D, an order of magnitude larger than previously supposed, and have used it to reinterpret earlier data indicating a variation of the a component with Ka. An improved molecular structure has been obtained. Astrophysical consequences of the large b component of the dipole moment are discussed. A table of transitions of potential astrophysical interest is presented.

Microwave and millimetre wave spectra of diazirine-d2: Rotational and hyperfine structure analysis and molecular structure

1985 ◽  
Vol 63 (9) ◽  
pp. 1173-1183 ◽  
Author(s):  
Udai P. Verma ◽  
Klaus Möller ◽  
Jürgen Vogt ◽  
Manfred Winnewisser ◽  
Jørn Johs. Christiansen
Keyword(s):  
Hyperfine Structure ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Quadrupole Coupling ◽  
Internuclear Distances ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants ◽  
Line Positions

The rotational spectrum of diazirine-d2, [Formula: see text], has been recorded in the ranges 8–40 and 100–400 GHz. The hyperfine structure of the measured rotational lines has been analyzed. The analysis required the treatment of two pairs of equivalent nuclei, which is discussed in detail. The deduced deuterium nuclear-quadrupole coupling constants are[Formula: see text]The quadrupole coupling constants of the nitrogen nuclei[Formula: see text]are taken from the parent species, and the spin-rotation coupling constants are[Formula: see text]The rotational and centrifugal distortion constants have been obtained for the ground vibrational state from the analysis of the unperturbed line positions. The complete rs structure of diazirine has been determined using the rotational constants of all available isotopomers of diazirine. The internuclear distances are rs(C—N) = 148.13(24) pm, rs(C—H) = 108.03(29) pm, and rs(N—N) = 122.80(25) pm, and the bond angles are [Formula: see text] and [Formula: see text], with the HCH plane perpendicular to the NCN plane.

The microwave spectrum of (Z)-Ethanimine

1980 ◽  
Vol 33 (1) ◽  
pp. 1 ◽  
Author(s):  
RD Brown ◽  
PD Godfry ◽  
DA Winkler
Keyword(s):  
Dipole Moment ◽  
Nitrogen Atom ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Methyl Group ◽  
Quadrupole Coupling ◽  
Asymmetric Rotor ◽  
Distortion Parameters

The microwave spectrum of ethanimine, CH3CH=NH, has been measured over the range of 18-76 GHz. A series of lines have been attributed to the Z-isomer. These have been fitted to an asymmetric rotor with inclusion of centrifugal distortion parameters. An excited torsional state has also been assigned and the barrier to internal rotation of the methyl group has been determined. The dipole moment has been evaluated from the Stark effect as 2.42 D. The quadrupole coupling constants of the nitrogen atom have been obtained from high-resolution studies. In contrast to methanimine, we found no evidence of magnetic hyperfine interaction in the structures of the multiplets.

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