Millimetre wave spectrum of silyl acetylene in the ground vibrational state

1982 ◽  
Vol 60 (8) ◽  
pp. 1079-1080 ◽  
Author(s):  
J. Carlier ◽  
A. Bauer
Keyword(s):  
Signal Processing ◽  
Vibrational State ◽  
Stark Effect ◽  
Wave Spectrum ◽  
Processing System ◽  
Centrifugal Distortion ◽  
Signal Processing System ◽  
Millimetre Wave ◽  
Ground Vibrational State ◽  
Centrifugal Distortion Constants

The millimetre wave spectrum of silyl acetylene in the ground vibrational state has been observed from 125 to 231 GHz. A new signal processing system using Stark effect has been carried out for the detection of the weakest lines. Refined rotational and centrifugal distortion constants have been derived.

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.

Millimetre-wave spectrum of HC17O+. Experimental and theoretical determination of the quadrupole coupling constant of the 17O nucleus

2001 ◽  
Vol 79 (2-3) ◽  
pp. 359-366 ◽  
Author(s):  
L Dore ◽  
C Puzzarini ◽  
G Cazzoli
Keyword(s):  
Wave Spectrum ◽  
Quadrupole Coupling Constant ◽  
Basis Sets ◽  
Coupling Constant ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Quadrupole Coupling ◽  
Self Consistent Field ◽  
Centrifugal Distortion Constants

The millimetre-wave spectrum of HC17O+ has been analyzed up to 348.2 GHz by recording the J = 2 [Formula: see text] 1 and J = 4 [Formula: see text] 3 rotational transitions. Present measurements and the previous detection of the J = 1 [Formula: see text] 0 transition carried out in this laboratory allowed us to determine accurate values of the rotational and centrifugal distortion constants, and of the nuclear quadrupole coupling (χ) and spin-rotation constants. Moreover, χ has been evaluated from the electric field gradient at the oxygen nucleus calculated by using the multiconfiguration self-consistent field approach plus subsequent multireference configuration interaction computation, employing basis sets of quadruple zeta quality. Excellent agreement with experiment has been obtained. In addition, the molecular dipole moment has been calculated at the same level of accuracy. PACS No.: 33.20Bx

Microwave and Millimeterwave Spectrum of Monofluoracetonitrile-15N (CH2FC15N). A Contribution to Molecular Structure

1987 ◽  
Vol 42 (11) ◽  
pp. 1275-1278
Author(s):  
H. Zerbe ◽  
A. Guarnieri
Keyword(s):  
Molecular Structure ◽  
Vibrational State ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Centrifugal Distortion Constants

The microwave and millimeterwave spectrum of 15N-fluoracetonitrile(CH2FC15N) in the ground vibrational state are investigated in the region between 8 and 150 GHz. The measured transitions are fitted to a Hamiltonian with three rotational constants, five quartic and seven sextic centrifugal distortion constants in the symmetric top limit of van Eijck-Typke and in the s-reduction of Watson. The rotational constants are used to improve the calculated r0 -restructure of the fluoracetonitrile molecule.

The Microwave and Millimetre Wave Spectrum, Molecular Constants, Dipole Moment, and Structure of Isocyanic Acid, HNCO

1975 ◽  
Vol 53 (19) ◽  
pp. 1869-1901 ◽  
Author(s):  
W. H. Hocking ◽  
M. C. L. Gerry ◽  
Gisbert Winnewisser
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Wave Spectrum ◽  
Rotational Constant ◽  
Isocyanic Acid ◽  
Centrifugal Distortion ◽  
Molecular Constants ◽  
Millimetre Wave ◽  
Order Of Magnitude ◽  
First Time

The microwave and millimetre wave spectra of six isotopic species of isocyanic acid, HNCO, have been measured. The molecule is a very slightly asymmetric prolate rotor. Besides the a type R branches, previously reported for two species, we have assigned for the first time a type Q branches and also some intense b type P and R branch transitions. Accurate values of the rotational constants have been determined. The rotational constant A0 is particularly large, with the result that the molecule undergoes very large centrifugal distortion, and terms up to the 12th power in the angular momentum are required to fit the spectrum. 14N nuclear quadrupole hyperfine splitting has been measured and accurate values for both χaa and (χbb − χcc) have been obtained, the latter for the first time. From the Stark effect of the b type transitions we have found the b component of the dipole moment to be 1.35 ± 0.1 D, an order of magnitude larger than previously supposed, and have used it to reinterpret earlier data indicating a variation of the a component with Ka. An improved molecular structure has been obtained. Astrophysical consequences of the large b component of the dipole moment are discussed. A table of transitions of potential astrophysical interest is presented.

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.

scholarly journals Ground State Centrifugal Distortion Constants of Vinyl Isocyanide, CH2-CH-NC, from the Microwave and Millimeter Wave Rotational Spectra

1975 ◽  
Vol 30 (5) ◽  
pp. 672-689 ◽  
Author(s):  
Koichi Yamada ◽  
Manfred Winnewisser
Keyword(s):  
Ground State ◽  
Hyperfine Splitting ◽  
Vibrational State ◽  
Frequency Region ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Ground Vibrational State ◽  
Rotational Spectra ◽  
Measured Absorption ◽  
Centrifugal Distortion Constants

Abstract The pure rotational spectrum of vinyl isocyanide in the ground vibrational state has been as-signed in the frequency region from 8 GHz to 180 GHz. The measured absorption lines encompass 157 a-type transitions from the qRK , qQ1, qQ2,qQ3, qQ4 and qQ5 branches and 48 b-type transitions from the rP0 , rP1, rP2, rP3 , rP4 , rP5, rQ0 , and rQ1 branches for values of J up to 54. The rotational constants have been refined and all quartic and sextic centrifugal distortion constants have been determined using Watson's reduced Hamiltonian. No quadrupole hyperfine splitting was observed.

Ground state spectroscopic constants and electric dipole moment of D14N12C32S from its microwave and millimetre wave spectra

1978 ◽  
Vol 56 (10) ◽  
pp. 1297-1307 ◽  
Author(s):  
L. B. Szalanski ◽  
M. C. L. Gerry ◽  
G. Winnewisser ◽  
K. Yamada ◽  
M. Winnewisser
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Wave Spectra ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants ◽  
First Time

The microwave and millimetre wave spectra of D14N12C32S in its ground vibrational state have been investigated in the frequency region 8–210 GHz. A large number of a-type Q branch and b-type P and R branch transitions up to J = 62 have been assigned and measured for the first time. Their frequencies have been combined with those of the a-type R branches up to K = 5 in an analysis for rotational, centrifugal distortion, and 14N quadrupole coupling constants. Constants obtained, in Watson's S reduction formalism, are: rotational constants in megahertz: A0 = 705 511(370); B0 = 5500.4391(15); C0 = 5445.2252(15); quartic centrifugal distortion constants in kilohertz: Dj = 1.0926(25); Djk = 1333.4(12); d1 = 3.455(5) × 10−2d2 = −7.8(14) × 10−3; 14N quadrupole coupling constants in megahertz: χaa = 1.19(6), χbb−χcc <0.05. The b-component of the dipole moment, μb, has been measured using the Stark effect as 1.08(15) D; this, when combined with μa = 1.67(3) D gives a total dipole moment of 1.99(15) D, essentially parallel to the HN bond.

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 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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