scholarly journals Rotational Spectrum of Methylcyanoacetylene A New Millimeter Wave Spectrometer

1983 ◽  
Vol 38 (1) ◽  
pp. 64-67 ◽  
Author(s):  
M. Bester ◽  
M. Tanimoto ◽  
B. Vowinkel ◽  
G. Winnewisser ◽  
Koichi Yamada
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Wave Spectra ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Reflex Klystron ◽  
Wave Spectrometer

Abstract The ground state rotational spectrum of methylcyanoacetylene, CH3CCCN, has been observed between 8 and 90 GHz, yielding precise rotational constants and a determination of the nuclear hyperfine costant eqQ = -4.0 ± 0.2 MHz. The millimeter wave spectra (70 - 90 GHz) were obtained with a newly constructed spectrometer, employing a synthesizer - controlled reflex klystron as source.

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 The observed transition frequencies were analyzed together with unpublished millimeter wave data of our group and with the data available in the literature.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.

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 Determination of a High Potential Barrier Hindering Internal Rotation from the Ground State Spectrum

1983 ◽  
Vol 38 (9) ◽  
pp. 1010-1014 ◽  
Author(s):  
W. Stahl ◽  
H. Dreizler ◽  
M. Hayashi
Keyword(s):  
Internal Rotation ◽  
Potential Barrier ◽  
Ground State ◽  
High Potential ◽  
Rotational Spectrum ◽  
High Potential Barrier

Abstract We present an analysis of the rotational spectrum of ethylchloride-35Cl in the ground state. The 35Cl-hfs analysis was extended and the barrier to internal rotation determined from narrow splittings of high J-transitions.

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

1985 ◽  
Vol 40 (3) ◽  
pp. 271-273 ◽  
Author(s):  
G. Bestmann ◽  
W. Lalowski ◽  
H. Dreizler
Keyword(s):  
Fine Structure ◽  
Internal Rotation ◽  
Ground State ◽  
Methyl Groups ◽  
Rotational Spectrum ◽  
Rotation Barrier ◽  
Rotation Axes ◽  
Internal Rotation Barrier ◽  
The Moment

The internal rotation barrier V3, the moment of inertia Iα of the methyl tops and the angle between the two internal rotation axes were determined from the torsional fine structure of the rotational spectrum in the torsional ground state. A tilt angle of 1.4° of the methyl groups toward each other results.

Determination of a High Barrier Hindering Internal Rotation from the Ground State Spectrum. The Methylbarrier of 1-Butyne

1985 ◽  
Vol 40 (3) ◽  
pp. 263-266 ◽  
Author(s):  
G. Bestmann ◽  
H. Dreizler
Keyword(s):  
Internal Rotation ◽  
Ground State ◽  
Rotational Spectrum ◽  
Rotational Spectra

With 1-butyne a series of barrier determinations from rotational spectra in the torsional ground state of ethyl compounds was continued. The barrier is different to the value from an analysis of the rotational spectrum of the first torsional state.

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.

Ground state spectroscopic constants of isothiocyanic acid, HNCS, from its microwave and millimeter wave spectra combined with far infrared data

1979 ◽  
Vol 78 (2) ◽  
pp. 189-202 ◽  
Author(s):  
Koichi Yamada ◽  
Manfred Winnewisser ◽  
Gisbert Winnewisser ◽  
L.B. Szalanski ◽  
M.C.L. Gerry
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Far Infrared ◽  
Spectroscopic Constants ◽  
Wave Spectra ◽  
Infrared Data

scholarly journals The millimeter-wave spectrum of methyl ketene and the astronomical search for it

2018 ◽  
Vol 619 ◽  
pp. A92 ◽  
Author(s):  
C. Bermúdez ◽  
B. Tercero ◽  
R. A. Motiyenko ◽  
L. Margulès ◽  
J. Cernicharo ◽  
...  
Keyword(s):  
Excited State ◽  
Millimeter Wave ◽  
Ground State ◽  
Wave Spectrum ◽  
High Mass ◽  
Mass Star ◽  
Rotational Spectrum ◽  
Star Forming ◽  
Dark Clouds ◽  
Star Forming Regions

Context. The analysis of isomeric species of a compound observed in the interstellar medium (ISM) is a useful tool to understand the chemistry of complex organic molecules. It could, likewise, assist in the detection of new species. Aims. Our goal consists in analyzing one of the two most stable species of the C3H4O family, methyl ketene, whose actual rotational parameters are not precise enough to allow its detection in the ISM. The obtained parameters will be used to search for it in the high-mass star-forming regions Orion KL and Sagittarius B2, as well as in the cold dark clouds TMC-1 in the Taurus Molecular Cloud and Barnard 1 (B1–b). Methods. A millimeter-wave room-temperature rotational spectrum of methyl ketene was recorded from 50 to 330 GHz. The internal rotation analysis of its ground state and first torsional excited state was performed with the rho-axis method employing the RAM36 program. Results. More than 3000 transitions of the rotational spectrum of the ground state (Kamax = 18) and first torsional excited state (Kamax = 13) of methyl ketene were fitted using a Hamiltonian that contains 41 parameters with a root mean square of 44 kHz. Column density limits were calculated but no lines were detected in the ISM belonging to methyl ketene.

Rotational Spectrum of cis-HS3D

1992 ◽  
Vol 47 (10) ◽  
pp. 1091-1093 ◽  
Author(s):  
M. Liedtke ◽  
A. H. Saleck ◽  
J. Behrend ◽  
G. Winnewisser ◽  
R. Klünsch ◽  
...  
Keyword(s):  
Ground State ◽  
Rotational Spectrum ◽  
Frequency Range ◽  
Rotational Constants ◽  
Vibrational Ground State ◽  
Q 30

AbstractThe rotational spectrum of HS3D in the vibrational ground state has been measured in the frequency range between 75 and 293 GHz. Up to now, about 180 Q-, 30 P-, and 70 R-branch c-type transitions have been identified. The preliminary rotational constants of the species observed support the cis-conformation established earlier from the H2S3 rotational spectrum.

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