scholarly journals Centrifugal Distortion Analysis of the Microwave and Millimeter Wave Spectra of Deuterated Ketenes1,2

1976 ◽  
Vol 31 (3-4) ◽  
pp. 272-282 ◽  
Author(s):  
László Nemes ◽  
Manfred Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Wave Spectra ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Planar Model ◽  
Distortion Analysis ◽  
Rotational Transitions

Measurements of R and Q branch a-type pure rotational transitions in the frequency range from 8 GHz to 220 GHz are reported for ketene-d1 and ketene-d2. The microwave and millimeter wave transitions were analysed in terms of Watson’s reduced Hamiltonian, including the sextic terms HKJ and HJK. The values of the inertial defect and the τ defect obtained from the centrifugal distortion analysis are in accord with the planar model for the ketene molecule.

scholarly journals Millimeter Wave Spectrum and Centrifugal Distortion Analysis of Difluorochloromethane CHF2Cl in the Ground State

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1165-1168 ◽  
Author(s):  
R. Spiehl ◽  
A. Guarnieri
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Wave Spectrum ◽  
Sixth Order ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Vibrational Ground State ◽  
Distortion Analysis

Abstract The rotational spectra of CHF235Cl and CHF237Cl (CFC22) in the vibrational ground state between 42 and 214 GHz are reported. A centrifugal distortion analysis up to the sixth order is carried out.

The Microwave Spectrum of Isopropyl Iodide: The Iodine Hyperfine Structure and a Centrifugal Distortion Analysis

1990 ◽  
Vol 45 (5) ◽  
pp. 715-723 ◽  
Author(s):  
Joachim Gripp ◽  
Helmut Dreizler
Keyword(s):  
Double Resonance ◽  
Rotational Constant ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Hamiltonian Matrix ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Least Squares Fit ◽  
Distortion Analysis ◽  
Centrifugal Distortion Constants

Abstract The ground stafe microwave spectrum of isopropyl iodide has been investigated by microwave Fourier transform (MWFT) spectroscopy. 212 hyperfine components of 39 mainly a-type transitions have been assigned from the measured spectra in the frequency range between 4 and 30 GHz. With a MWFT double resonance modulation (MWFTDR) spectrometer a weak c-type transition and a "forbidden" ΔJ = 2 line could be observed. The spectra were analysed using a diagonalization procedure of the complete Hamiltonian matrix and a simultaneous least squares fit of the rotational, quartic centrifugal distortion and the iodine quadrupole and spin rotation coupling constants directly to the measured frequencies. A set of 14 constants could be obtained with high accuracy. The rotational constant A and some of the centrifugal distortion constants could be improved using some large higher order quadrupole perturbations and the results of the MWFTDR measurements for the analysis.

The Rotational Spectrum of Monothioformic Acid IV. cis- and trans-H13C(:O)SH and HC(:18O)SH

1977 ◽  
Vol 32 (10) ◽  
pp. 1108-1118 ◽  
Author(s):  
William H. Hocking ◽  
Gisbert Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Vibrational State ◽  
Wave Spectra ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Ground Vibrational State ◽  
Bond Angles ◽  
Isotopic Species ◽  
Cis And Trans ◽  
Trans Structure

The microwave and millimeter wave spectra of two isotopically substituted species of monothioformic acid, H13COSH and HC18OSH. have been investigated. Over 60 rotational transitions in the ground vibrational state have been assigned and measured for both the eis and trans thiol rotamers. HC(:O)SH. of each isotopic species. Rotational constants and quartic centrifugal distortion comstants of H13COSH and HC18OSH have been determined from the observed spectra. These data have been combined with previously published results on HCOSH, DCOSH. HCOSD and HCO34SH to obtain complete substitutions structures for the planar eis and trans rotamers of HC(:O)SH. All of the in-plane bond angles as well as the SH distance are significantly different for the two rotamers. For the eis rotamer the HSC and HCS angles increase by more than 2°, the OCS angle decreases by more than 3°, and the SH bond shortens compared to the trans rotamer geometry. The eis structure is: r(C-H) = 1.104 ± 0.003 Å, r(C = O) 1.203 ± 0.003 Å. r(C-S) = 1.771 ± 0.003 Å, r(S-H) = 1.335 ± 0.002 Å, ∢(OCS) = 122.5° ± 0.3°, ∢(HSC) = 94.9° ± 0.2° and ∢(HCS) = 114.4° ± 0.2°; whereas the trans structure is: r(C-S) = 1.104 ± 0.003 Å. r(C = O) = 1.205 ± 0.003 Å, r(C-S) = 1.768 ± 0.003 Å, r(S-H) = 1.354 ± 0.002 Å. ∢(OCS) = 125.9° ± 0.3°, (HSC) = 92.5° ± 0.2° and ∢(HCS) = 111.0° ± 0.2°

Sub-millimeter Wave Spectra of Cyanoacetylene and Revised Ground State Constants

1995 ◽  
Vol 50 (12) ◽  
pp. 1179-1181 ◽  
Author(s):  
K. M. T. Yamada ◽  
A. Moravec ◽  
G. Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Vibrational State ◽  
Frequency Region ◽  
Wave Spectra ◽  
Centrifugal Distortion ◽  
Ground Vibrational State ◽  
Wave Data ◽  
Centrifugal Distortion Constants ◽  
Wave Spectrometer

Abstract Sixteen new rotational transitions of cyanoacetylene in the ground vibrational state have been measured in the frequency region from 570 GHz to 710 GHz by the Cologne sub-millimeter wave spectrometer. The observed transition frequencies were analyzed together with unpublished millimeter wave data of our group and with the data available in the literature. Precise rota­ tional constant and the quartic and sextic centrifugal distortion constants have been determined; B = 4549.058224(37) MHz, D = 0.544110(19) kHz, and H = 0.0345(21) mHz.

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