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.

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 Ground State Microwave Spectrum and Dipole Moment of 2-Isocyano-Propane

1989 ◽  
Vol 44 (7) ◽  
pp. 680-682 ◽  
Author(s):  
Michael Krüger ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Dipole Moment ◽  
Ground State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Total Dipole Moment ◽  
Rotational Constants ◽  
Centrifugal Distortion Constants

Abstract The ground state rotational spectrum of 2-isocyano-propane is assigned. The rotational constants and the quartic centrifugal distortion constants are determined by Microwave Fourier Transform (MWFT) Spectroscopy. The analysis of the Stark effect leads to a total dipole moment of 4.055(1) D.

Centrifugal Distortion and Ground State Internal Rotation Analysis of the Microwave Spectrum of Dimethylsulfoxide

1983 ◽  
Vol 38 (6) ◽  
pp. 668-675 ◽  
Author(s):  
E. Fliege ◽  
H. Dreizler ◽  
V. Typke
Keyword(s):  
Internal Rotation ◽  
Ground State ◽  
Accurate Determination ◽  
Microwave Spectrum ◽  
Rotation Barrier ◽  
Centrifugal Distortion ◽  
Distortion Analysis ◽  
Internal Rotation Barrier ◽  
Centrifugal Distortion Constants

The torsional Fine structure of dimethylsulfoxide has been reinvestigated with MWFT-spectroscopy. The higher resolution results in a more accurate determination of the internal rotation barrier V3. The centrifugal distortion analysis is extended to sixth order. The prediction of lines is excellent, but some centrifugal distortion constants are poorly determined

Terahertz Spectrum of Trioxane

1996 ◽  
Vol 51 (1-2) ◽  
pp. 123-128 ◽  
Author(s):  
H. Klein ◽  
S. P. Belov ◽  
G. Winnewisser
Keyword(s):  
Ground State ◽  
Rotational Constant ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Experimental Accuracy ◽  
Terahertz Spectrum ◽  
Vibrational Ground State ◽  
Isotopic Species ◽  
Centrifugal Distortion Constants

Abstract The pure rotational spectrum of trioxane, (H2CO)3 the trimer of formaldehyde, has been recorded with high resolution in the frequency range between 326 and 947 GHz for the main isotopomer, the 13 C, and the 18O isotopic species in the vibrational ground state. These new high J and K data reveal that the molecule is fairly rigid. For the constants determinable from the recorded high J and K spectra (J = 90 and K = 75) the rotational constant B = 5273.257 180(33) MHz,the two quartic centrifugal distortion constants DJ, and DJK, and the three sextic constants HJ, HJK, and HKJ are needed in the fit to reproduce the measured spectra within experimental accuracy. In addition, for the 13C isotopomer the sextic constants HJK and HKJ are determined as well as the off-diagonal parameters d1 and d2.

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 cis-Propanal

1982 ◽  
Vol 37 (9) ◽  
pp. 1035-1037 ◽  
Author(s):  
J. A. Hardy ◽  
A. P. Cox ◽  
E. Fliege ◽  
H. Dreizler
Keyword(s):  
Internal Rotation ◽  
Potential Barrier ◽  
Ground State ◽  
Model Errors ◽  
Centrifugal Distortion ◽  
Methyl Group ◽  
Distortion Analysis ◽  
High Potential Barrier ◽  
Double Resonances

Abstract The barrier hindering internal rotation of the methyl group was determined by analysing the splittings of rotational lines in the ground state. So model errors are minimized. The assignment was checked by double resonances and a centrifugal distortion analysis.

Ground State Centrifugal Distortion Constants of Trans-Acrolein, CH2 = CH — CHO from the Microwave and Millimeter Wave Rotational Spectra 1,2

1975 ◽  
Vol 30 (8) ◽  
pp. 1001-1014 ◽  
Author(s):  
Manfred Winnewisser ◽  
Gisbert Winnewisser ◽  
T. Honda ◽  
E. Hirota
Keyword(s):  
Ground State ◽  
Vibrational State ◽  
Line Search ◽  
Frequency Region ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Measured Absorption ◽  
Centrifugal Distortion Constants ◽  
Line Positions

Abstract The pure rotational spectrum of trans-acrolein in the ground vibrational state has been assigned in the frequency region from 8 GHz to 180 GHz. The measured absorption lines encompass a-type transitions from the qRK, qQ1, qQ2 branches and 6-type transitions from the rP0, rP1, rP2, rR0 brandies for values of J up to 23. The rotational constants have been refined and all quartic and sextic centrifugal distortion constants have been determined using Watson's reduced Hamiltonian. This information has been used to predict line positions of astrophysical interest to warrant the interstellar line search for trans-acrolein.

scholarly journals The Rotational Spectrum of (17O)Ketene

2001 ◽  
Vol 56 (6-7) ◽  
pp. 440-446 ◽  
Author(s):  
A. Guarnieri ◽  
A. Huckauf
Keyword(s):  
Molecular Beam ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Coupling Structure ◽  
Quadrupole Coupling ◽  
Quadrupole Constant ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract The rotational spectrum of H2CC17O in the ground vibrational state has been investigated between 20 and 330 GHz. From 82 R-branch transitions a set of rotational constants and several centrifugal distortion constants could be derived, employing the Watson 5-reduction formalism. The obtained rotational constants in MHz are: A = 282071.6(223), B = 10013.4764(28), C = 9655.9118(24). The nuclear quadrupole coupling structure of the J'Ka'Kc' <- JKaKc = 101 O00 line has been recorded by means of molecular beam Fourier transform microwave spectroscopy allowing the determination of the nuclear quadrupole constant Xaa. = -1.534(54) MHz (without considering the spin-rotation interaction). A recalculation of the rs-structure has also been carried out, using the constants of the new isotopomer. The result agrees with the values reported by East et al. in 1995. This is, to our knowledge, the first reported investigation of the H2CC17O rotational spectrum.

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.

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