Microwave spectrum and molecular structure of silacyclopropenylidene c-C2H2Si

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1206-1212 ◽  
Author(s):  
Mitsuaki Izuha ◽  
Satoshi Yamamoto ◽  
Shuji Saito
Keyword(s):  
Microwave Spectrum ◽  
Frequency Region ◽  
Spectral Lines ◽  
Absorption Cell ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Microwave Spectrometer ◽  
Centrifugal Distortion Constants

The rotational spectra of silacyclopropenylidene, c-C2H2Si, and its isotopic species (C2H229Si, C2D2Si, 13C2H2Si) were observed in the frequency region of 220–400 GHz by using a source-modulated microwave spectrometer combined with a free space absorption cell. c-C2H2Si was produced in the cell by discharging a mixture of SiH4, C2H2, and He. Least-squares analyses of the observed spectral lines yielded the rotational constants and the centrifugal distortion constants for the normal and its isotopic species. From the observed rotational constants, the rs structure was determined: rs (C=C) = 1.3458 Å, rs (C—Si) = 1.8200 Å rs (C—H) = 1.0795 Å, and [Formula: see text]. (1 Å = 10−10 m.)

Mikrowellenspektrum von 12C34SF37Cl

1976 ◽  
Vol 31 (6) ◽  
pp. 594-601 ◽  
Author(s):  
R. Hamm ◽  
H. J. Kohrmann ◽  
H. Günther ◽  
W. Zeil
Keyword(s):  
Equilibrium Structure ◽  
Microwave Spectrum ◽  
Natural Abundance ◽  
Least Square ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Isotopic Species ◽  
Planar Molecule ◽  
Least Square Fit ◽  
Centrifugal Distortion Constants

The microwave spectrum of the isotopic species 12C34SF37Cl has been measured in natural abundance. The three rotational constants and five quartic centrifugal distortion constants have been determined by a least square fit. In comparison with our former calculations, the five structural r0-parameters of the planar molecule have now been determined from eight rotational constants instead of six, thus yielding remarkably smaller confidence intervalls. Furthermore an re-structure has been calculated and an equilibrium-structure has been estimated

The Centimeter and Millimeter Microwave Spectrum of 1,1-Difluoro-2-Chloroethylene

1993 ◽  
Vol 48 (3) ◽  
pp. 514-518 ◽  
Author(s):  
Luis A. Leal ◽  
J. C. López ◽  
J. L. Alonso ◽  
A. Guarnieri
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Coupling Analysis ◽  
Rotational Spectra ◽  
First Order ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants

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.

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 Methane-d2, CH2D2

1975 ◽  
Vol 53 (19) ◽  
pp. 2023-2028 ◽  
Author(s):  
Eizi Hirota ◽  
Misako Imachi
Keyword(s):  
Dipole Moment ◽  
Microwave Spectrum ◽  
Normal Coordinate Analysis ◽  
Centrifugal Distortion ◽  
Normal Coordinate ◽  
Rotational Constants ◽  
Microwave Spectrometer ◽  
Rotational Transitions ◽  
Centrifugal Distortion Constants

Three rotational transitions of methane-d2 were observed by a source-modulation microwave spectrometer. The two differences in the rotational constants, A – C and B – C, were determined to be 37 555.758 and 13 664.280 MHz, respectively, from the observed frequencies of 110 ← 101 and 211 ← 202 after correcting for the centrifugal distortion effects. The centrifugal distortion constants were evaluated by a normal coordinate analysis. The dipole moment of CH2D2 was determined to be 0.014 ± 0.005 D, by comparing the intensity of 211 ← 202 with that of an oxygen line.

Microwave spectrum and molecular structure of the HS2 radical

1994 ◽  
Vol 72 (11-12) ◽  
pp. 954-962 ◽  
Author(s):  
Satoshi Yamamoto ◽  
Shuji Saito
Keyword(s):  
Zero Point ◽  
Force Constants ◽  
Spectral Lines ◽  
Centrifugal Distortion ◽  
Harmonic Force ◽  
Rotational Constants ◽  
Anharmonic Constants ◽  
Microwave Spectrometer ◽  
Centrifugal Distortion Constants ◽  
Space Cell

Rotational spectral lines of the HS2 and DS2 radicals in the 2A″ ground electronic state are detected by a source-modulation microwave spectrometer combined with a free-space cell. The HS2 radical is produced in the cell by discharging a pure H2S gas. The spectrum of DS2 is observed by using a mixture of H2S and D2. The rotational constants, the centrifugal distortion constants, the spin-rotation interaction constants with their centrifugal distortion corrections, and the hyperfine interaction constants for the hydrogen nucleus are determined by least-squares analyses. The harmonic force constants are evaluated from the observed centrifugal distortion constants in combination with the vibrational frequencies reported previously. The zero-point average structure of HS2 is determined from the observed rotational constants of HS2 and DS2 with the aid of the harmonic force constants: rz(S—S) = 1.9650 (7) Å, rz (S—H) = 1.362 (3) Å, and αz (HSS) = 101/7 (4)° (1 Å = 10−10 m). The equilibrium distances for the S—S and S—H bonds are derived to be 1.9606 (7) Å and 1.352 (3) Å, respectively, by assuming the anharmonic constants of the corresponding diatomic molecules.

The Rotational Spectrum of Ketene Isotopomers with 18O and 13C Revisited

2003 ◽  
Vol 58 (5-6) ◽  
pp. 275-279 ◽  
Author(s):  
A. Guarnieri ◽  
A. Huckaufa
Keyword(s):  
Vibrational State ◽  
Frequency Region ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Rotational Spectra ◽  
Main Species ◽  
Centrifugal Distortion Constants

The pure rotational spectra of [18O]ketene, H2C=C18O, [1-13C]ketene, H2C=13CO, and [2-13C]ketene, H213C=CO, have been revisited in the frequency region 200 - 350 GHz in the ground vibrational state.From more than 100 R-branch transitions for each isotopomer a set of rotational and centrifugal distortion constants could be derived using the Watson S-reduction formalism. The values obtained for the rotational constants B and C agree very well with results of former investigations. The agreement is worse with respect to the A constants, but our newly determined A values agree well with the corresponding values of the main species and the 17O isotopomer.

Microwave Spectrum and Barrier to Internal RotationinCH3COC15N

1977 ◽  
Vol 32 (7) ◽  
pp. 761-764 ◽  
Author(s):  
G. K. Pandey ◽  
H. Dreizler
Keyword(s):  
Least Squares ◽  
Potential Barrier ◽  
Ground State ◽  
Microwave Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Least Squares Fit ◽  
Barrier Parameter ◽  
Centrifugal Distortion Constants

Abstract The ground state rotational spectra of the 15N isotopic species of acetyl cyanide have been measured in the region from 8 to 40 GHz. The rotational and centrifugal distortion constants have been determined by a least squares fit to about 38 transition frequencies with J ≦ 14. The potential barrier parameter V3 and the angle a between the top axis and the 'a-axis' have been determined by a least squares of the (A-E) splittings of about 27 transitions. The methyl top moment of inertia was fixed at 3.14 amu Å2

Mikrowellenspektrum, rotationsspektroskopische Konstanten und r0-Struktur des CSFCl / Microwave Spectrum, Spectroscopic Constants and r0 Structure of CSFCl

1975 ◽  
Vol 30 (2) ◽  
pp. 183-194 ◽  
Author(s):  
Hans Joachim Kohrmann ◽  
Werner Zeil
Keyword(s):  
Microwave Spectrum ◽  
Spectroscopic Constants ◽  
Structure Parameters ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Isotopic Species ◽  
Centrifugal Distortion Constants

Abstract The microwave spectra of following isotopic species 12. 12C32S19F35Cl, 12C32S19F37Cl, 12C34S19F35Cl, 13C32S19F35Cl have been measured. The rotational constants and the centrifugal distortion constants have been determined and a r0 structure calculated. The structure parameters are: rCS 1.595° Å, rCF 1.326° Å, rCCl 1.715° Å, ∢ SCF 123.82°, SCCl 127.12°.

Centrifugal Distortion Effect in the Microwave Spectrum of Nitric Acid

1977 ◽  
Vol 32 (2) ◽  
pp. 183-184 ◽  
Author(s):  
Vijay Kumar Kaushik ◽  
Putcha Venkateswarlu
Keyword(s):  
Nitric Acid ◽  
Microwave Spectrum ◽  
Frequency Region ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Microwave Rotational Spectrum ◽  
Distortion Effect ◽  
Centrifugal Distortion Constants

The microwave rotational spectrum of Nitric Acid has been analysed in the frequency region 8000-35000 MHz and up to J=12. The analysis gives refined rotational constants and all the quartic centrifugal distortion constants

scholarly journals The Millimeterwave Spectrum of Four Rare Ketene Isotopomers

2005 ◽  
Vol 60 (8-9) ◽  
pp. 619-628 ◽  
Author(s):  
Antonio Guarnieri
Keyword(s):  
Vibrational State ◽  
Frequency Region ◽  
Spectral Lines ◽  
Centrifugal Distortion ◽  
Ground Vibrational State ◽  
Rotational Spectra ◽  
Centrifugal Distortion Constants ◽  
Mass Dependent

The pure rotational spectra in the ground vibrational state of (1,2-13C)ketene, H213C=13CO, (D2,1-13C)ketene, D2C=13CO, (D2,2-13C)ketene, D213C=CO, and (D2,18O)ketene, D2C=C18O, have been observed in the frequency region 200 - 350 GHz. All the spectral lines have been measured in natural abundances with a source modulated millimeterwave spectrometer.From the measured R-branch transitions a set of rotational and centrifugal distortion constants for each isotopomer could be derived, using the Watson S-reduction formalism. Further, the rotational spectra of the two isotopomers (4,5-D)ketene, D2CCO, and (4-D)ketene, DHCCO, which were already measured several years ago, have been extended to higher J-values and higher frequencies, as it is the case for all investigated isotopomers of this work. As a result of these studies a calculation of a mass-dependent structure will be the topic of a next paper.

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