Impact of Sub-Doppler Measurements on Centrifugal-Distortion Terms: Rotational Spectrum of Methyl Fluoride Revisited

2014 ◽  
Vol 119 (9) ◽  
pp. 1765-1773 ◽  
Author(s):  
Gabriele Cazzoli ◽  
Cristina Puzzarini
Keyword(s):  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Methyl Fluoride

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.

The microwave spectrum of the ClS2 free radical

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1043-1050 ◽  
Author(s):  
Masaharu Fujitake ◽  
Eizi Hirota
Keyword(s):  
Free Radical ◽  
Force Field ◽  
Electronic Spectroscopy ◽  
Spin Rotation ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Harmonic Force ◽  
Isotopic Species ◽  
Spin Resonance ◽  
Centrifugal Distortion Constants

The rotational spectrum of the ClS2 free radical in the gaseous phase has been observed in the millimetre- and submillimetre-wave regions. The ClS2 radical was generated by a dc glow discharge in either S2Cl2 or SCl2. Both a- and b-type R-branch transitions, most of which were split into two fine structure components, were detected for both of the 35Cl and 37Cl isotopic species in the ground vibronic state. As expected from the small hyperfine interaction constants reported by an electron spin resonance (ESR) study, the hyperfine structure was resolved for none of the transitions observed in the present study. Analysis of the observed transition frequencies yielded rotational and centrifugal distortion constants and also spin–rotation interaction constants with their centrifugal corrections. The spin–rotation interaction constants obtained in the present study were consistent with g values of the ESR study. The rotational constants of the two isotopic species led to the structure parameters r(S—S) = 1.906 (7) Å, r(S—Cl) = 2.071 (5) Å, and θ(SSCl) = 110.3 (4)°. A harmonic force field was derived from the observed centrifugal distortion constants and inertial defects combined with the ν1 frequency reported in literature on electronic spectroscopy. This harmonic force field yielded the ν2 and ν3 frequencies (445 (21) and 213.0 (2) cm−1, respectively, for 35ClS2), which differed considerably from the values reported previously.

The 33S Nuclear Quadrupole Hyperfine Structure in the Rotational Spectrum of 32S, 33S Dimethyl Disulfide

1995 ◽  
Vol 50 (2-3) ◽  
pp. 131-136 ◽  
Author(s):  
H. Hartwig ◽  
U. Kretschmer ◽  
H. Dreizler
Keyword(s):  
Molecular Beam ◽  
Dimethyl Disulfide ◽  
Microwave Spectroscopy ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Coupling Tensor ◽  
Quadrupole Coupling ◽  
Rotation Parameters ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract We investigated the rotational spectrum of 32S, 33S dimethyl disulfide in natural abundance by molecular beam Fourier transform microwave spectroscopy. We were able to determine the com­plete 33S quadrupole coupling tensor, the rotational and centrifugal distortion constants and the internal rotation parameters of the two methyl tops. The rotational constants were found to be A = 8113.8847(23) MHz, B = 2800.6203(30) MHz and C = 2557.2245 (32) MHz. The results are compared with former publications.

The Rotational Spectrum of Monothioformic Acid. I. cis-and trans-HC(:O)SH1,2

1976 ◽  
Vol 31 (5) ◽  
pp. 422-437
Author(s):  
William H. Hocking ◽  
Gisbert Winnewisser
Keyword(s):  
Frequency Region ◽  
Absorption Lines ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Astrophysical Interest ◽  
Rotational Spectra ◽  
Measured Line ◽  
Centrifugal Distortion Constants ◽  
Cis And Trans ◽  
Line Positions

Abstract The rotational spectra of the two abundant isomers of monothioformic acid, cis- and trans- HC(:O)SH, have been assigned in the frequency region 8 -250 GHz. Over 90 a-type transitions and over 60 b-type transitions have been measured for each rotamer. The a-type transitions belong to the qRK , qQ1, qQ2, qQ3 and qQ4 branches and the b-type absorption lines encompass the Ka = 1 - 0, 2 - 1, 3 - 2, 4 - 3 and 5 - 4 rotational sub-bands. The rotational constants and all quartic and sextic centrifugal distortion constants have been determined for each rotamer using Watson's reduced Hamiltonian. In addition to the measured line positions the frequencies of some selected low-J transitions, not observed in this work but of potential astrophysical interest, have been listed as an aid in the interstellar search for monothioformic acid.

Millimetre wave spectrum of methyl mercaptan

1980 ◽  
Vol 58 (11) ◽  
pp. 1640-1648 ◽  
Author(s):  
R. M. Lees ◽  
M. Ali Mohammadi
Keyword(s):  
Interstellar Medium ◽  
Least Squares ◽  
Wave Spectrum ◽  
Methyl Mercaptan ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Torsion Vibration ◽  
Vibration Rotation ◽  
Centrifugal Distortion Constants

An investigation of the rotational spectrum of CH332SH, one of the most recent molecules to be detected in the interstellar medium, has been carried out over the 25–107 GHz region. The frequencies of a-type Δk = 0 R-branch transitions have been measured for the J = 1 ← 0 up to J = 4 ← 3 multiplets for torsional states νt = 0–3. In addition, many P-, Q-, and R-branch transitions with Δk ≠ 0 have been identified in order to provide a catalogue of lines for potential radio astronomical applications. Improved values of rotational and centrifugal distortion constants, a-type torsion–vibration–rotation interaction constants, and torsional barrier parameters (V3 = 444.76 cm−1; effective V6 = −2.07 cm−1) have been determined from least-squares analyses of the spectra.

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.

Millimeter-Wave Spectrum of Ethyl Acetylene Centrifugal Distortion, Coriolis Interaction and Internal Rotation

1983 ◽  
Vol 38 (4) ◽  
pp. 447-451 ◽  
Author(s):  
J. Demaison ◽  
D. Boucher ◽  
J. Burie ◽  
A. Dubrulle
Keyword(s):  
Excited State ◽  
Internal Rotation ◽  
Plane Deformation ◽  
Wave Spectrum ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Coriolis Interaction ◽  
Methyl Group ◽  
First Excited State ◽  
Methyl Torsion

The rotational spectrum of ethyl acetylene has been investigated between 70 and 320 GHz. A Coriolis interaction has been found between the first excited state of the methyl torsion and the C - C = C in plane deformation. Splittings of transitions in the first excited torsional state show that the barrier hindering internal rotation of the methyl group amounts to 3271 cal/mole.

Sign in / Sign up

Export Citation Format

Share Document