scholarly journals The Rotational Spectrum of Propane Centrifugal Distortion Analysis

1985 ◽  
Vol 40 (5) ◽  
pp. 508-510 ◽  
Author(s):  
G. Bestmann ◽  
H. Dreizler ◽  
J. M. Vacherand ◽  
D. Boucher ◽  
B. P. van Eijck ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Millimeter Wave ◽  
Ground State ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Astrophysical Interest ◽  
Distortion Analysis ◽  
Wave Spectrometer

The ground state rotational spectrum of propane has been investigated between 6.4 and 26.5 GHz with a microwave Fourier transform spectrometer and between 140 and 300 GHz with a millimeter-wave spectrometer. High J transitions have been measured and fitted to a centrifugally distorted Hamiltonian including some sextic coefficients. The results of the analysis are sufficiently accurate for the prediction of all strong transitions of astrophysical interest.

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.

Determination of a High Potential Barrier Hindering Internal Rotation from the Ground State Spectrum. The Methylbarrier of Ethylbromide

1985 ◽  
Vol 40 (6) ◽  
pp. 575-587 ◽  
Author(s):  
J. Gripp ◽  
H. Dreizler ◽  
R. Schwarz
Keyword(s):  
Hyperfine Structure ◽  
Internal Rotation ◽  
Potential Barrier ◽  
Ground State ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Vibrational Ground State ◽  
Distortion Analysis ◽  
High Potential Barrier

For ethylbromide a determination of the parameters of internal rotation is given derived from the rotational spectrum of the torsional and vibrational ground state. The Br-hyperfine structure is reanalysed with higher precision. As high J transitions were measured a centrifugal distortion analysis was necessary.

The Microwave Ground State Spectra of Methylphosphine-Borane-(11B) and Methylphosphine-Trideuteroborane-(11B)

1986 ◽  
Vol 41 (6) ◽  
pp. 835-854
Author(s):  
W. Kasten ◽  
H. Dreizler ◽  
R. L. Kuczkowski ◽  
M. Soltis LaBarge
Keyword(s):  
Fourier Transform ◽  
Fine Structure ◽  
Ground State ◽  
Bond Order ◽  
Fourier Transform Spectroscopy ◽  
Centrifugal Distortion ◽  
Distortion Analysis ◽  
Nuclear Quadrupole ◽  
Hyperfine Splittings

The microwave ground state spectra of methylphosphine-borane-(11B) and methylphosphinetrideuteroborane-(11B) have been measured by microwave Fourier transform spectroscopy and analysed for 11B-nuclear quadrupole hyperfine splittings and CH3 and BH3 torsion fine structure. As high J transitions were measured a centrifugal distortion analysis was necessary. The B-P bond order is discussed.

14N Quadrupole Coupling in the Rotational Spectrum of Ethyl Nitrite

1988 ◽  
Vol 43 (5) ◽  
pp. 469-475 ◽  
Author(s):  
Ch. Keussen ◽  
U. Andresen ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Ground State ◽  
Fourier Transform Spectroscopy ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Isomers ◽  
Quantum Numbers ◽  
Quadrupole Coupling ◽  
Ethyl Nitrite

We investigated the 14N quadrupole coupling of three rotational isomers of ethyl nitrite in the ground state by microwave Fourier transform spectroscopy. Centrifugal distortion analyses were necessary to assign the transitions with high J quantum numbers. We found an additional splitting of some c-type transitions of the trans-gauche rotamer presumably arising from tunneling through the barrier separating the two equivalent gauche forms. This assumption could not be confirmed yet.

Pure rotational spectrum of 13CD4 and isotope effects on the tensorial centrifugal-distortion constants of methane

1987 ◽  
Vol 65 (1) ◽  
pp. 32-37 ◽  
Author(s):  
W. A. Kreiner ◽  
P. Müller ◽  
L. Jörissen ◽  
M. Oldani ◽  
A. Bauder
Keyword(s):  
Fourier Transform ◽  
Radio Frequency ◽  
Ground State ◽  
Isotope Effects ◽  
Double Resonance ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Theoretical Predictions ◽  
Deuterium Isotope Effects ◽  
Centrifugal Distortion Constants

Infrared-laser – radio-frequency double-resonance experiments and pulsed-microwave Fourier-transform measurements have been performed with 13CD4. From 25 observed ΔJ = 0 transitions in the vibronic ground state, the tensorial centrifugal-distortion constants Dt = 32.6600(12) kHz, H4t = −2.0302(61) Hz, H6t = 1.1692(29) Hz, L4t = 1.201(77) × 10−4 Hz, L6t = −1.353(63) × 10−4 Hz, and L8t = −1.466(46) × 10−4 Hz have been determined. Experimental carbon-13 and deuterium isotope effects on the tensorial centrifugal-distortion constants of methane have been compared with theoretical predictions.

Centrifugal Distortion Parameters of Fulminic Acid, HCNO, from the Millimeter-Wave Rotational Spectra

1971 ◽  
Vol 26 (1) ◽  
pp. 128-131 ◽  
Author(s):  
Manfred Winnewisser ◽  
Brenda P. Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Molecular Constants ◽  
Rotational Spectra ◽  
First Excited State ◽  
Bending Modes ◽  
Distortion Parameters

Abstract A newly designed millimeter-wave spectrometer has been employed for precise measurements of the millimeter-wave rotational spectrum of HCNO. Absorptions in several excited vibrational states as well as the ground state could be measured. The present paper presents the observed frequen­ cies and molecular constants obtained for the ground state and the first excited state of v4 and of v5, the vibrational bending modes

Investigation of the Microwave Spectrum of Cyclopropyl Isocyanate. An Example for the Failure of Centrifugal Distortion Theory

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1175-1184 ◽  
Author(s):  
C. Heldmann ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Ground State ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Vibrational Ground State ◽  
Quadrupole Coupling

Abstract The vibrational ground state microwave spectrum of cyclopropyl isocyanate was investigated in the region from 8.4 to 40 GHz by microwave Fourier transform (MWFT) spectroscopy. The quadru-pole hyperfine structure was resolved and assigned. The quadrupole coupling constants are given. With respect to the data given in the literature up to now, this work led to a more profound description of the pure rotational spectrum. Furthermore, some interesting and surprising results concerning the effect of centrifugal distortion are presented. Compared to hitherto existing investi-gations, these results indicate a more complicated conformational behaviour of cyclopropyl iso-cyanate.

Millimeter Wave Rotational Spectrum and Centrifugal Distortion of Thioketene, H2C==C=S

1980 ◽  
Vol 35 (5) ◽  
pp. 483-489 ◽  
Author(s):  
Manfred Winnewisser ◽  
Eckhard Schäfer
Keyword(s):  
Dipole Moment ◽  
Ground State ◽  
Wavelength Region ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Millimeter Wavelength ◽  
Vibrational Ground State ◽  
Distortion Analysis ◽  
Centrifugal Distortion Constants

Abstract a-type rotational transitions of molecules in the vibrational ground state of thioketene, H2C=C=S, have been measured in the millimeter wavelength region. The measurements yielded improved rotational constants:A = 286 655(82) MHz,B = 5 659.47596(72) MHz,C = 5 544.51269(72) MHz.A detailed centrifugal distortion analysis by means of Watson's S-reduced Hamiltonian led to the determination of four quartic, two sextic and two higher order distortion constants:DJ = 1.08569(4) kHz, HJK = 0.716(20) Hz, DJK = 168.269(77) kHz, HKJ = -408.7(73) Hz, D1 = -25.46(68) Hz, LKJ = 0.65(24) Hz, d2 = - 5.21(35) Hz, SKJ = -0.0533(24) Hz. Effective rotational and centrifugal distortion constants using planarity conditions were calculated. The electric dipole moment of thioketene was determined to be μ = 1.01(3) D.

Analysis of Centrifugal Distortion Effects in the Rotational Spectrum of Formyl Fluoride

1981 ◽  
Vol 36 (10) ◽  
pp. 1057-1061 ◽  
Author(s):  
Harold Jones ◽  
Volker Typke
Keyword(s):  
Ground State ◽  
Vibrational State ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Distortion Analysis

The measurements of the ground state spectra of both HCOF and DCOF have been extended to high-J transition. The centrifugal distortion analysis clearly showed that in HCOF the inclusion of sextic terms is absolutely necessary, whereas the effects from this source in DCOF are smaller but not negligible. The planarity condition for the sextic terms was introduced to reduce the number of parameters. Spectra in the lowest vibrational state of both HCOF and DCOF were also treated.

Centrifugal Distortion and Internal Rotation Analysis of the Rotational Spectrum of Methyl Thiocyanate

1986 ◽  
Vol 41 (5) ◽  
pp. 743-746 ◽  
Author(s):  
H. Maes ◽  
B. P. van Eijck ◽  
A. Dubrulle ◽  
J. Demaison
Keyword(s):  
Internal Rotation ◽  
Ground State ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Astrophysical Interest ◽  
Rotation Parameters ◽  
Methyl Thiocyanate

The ground state rotational spectrum of methyl thiocyanate has been investigated between 7 and 300 GHz (J ≦ 38 and K_ ≦ 25). An overall fit of the measurements using the Internal Axis Method has allowed us to accurately determine the internal rotation parameters. For the A substate effective rotational parameters are given which allow the calculation of transition frequencies of possible astrophysical interest.

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