The Rotational Spectrum of 2,2-Dimethylthiirane

1993 ◽  
Vol 48 (11) ◽  
pp. 1102-1106 ◽  
Author(s):  
H. Hartwig ◽  
H. Dreizler
Keyword(s):  
Excited States ◽  
Ground State ◽  
Heavy Atom ◽  
Natural Abundance ◽  
Structure Parameters ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Centrifugal Distortion Constants ◽  
Potential Parameters

Abstract The rotational spectrum of 2,2-dimethylthiirane (isobutylene sulfide) has been assigned for the ground and torsionally excited states. The rotational and centrifugal distortion constants, as well as the potential parameters V3 and V´1 2 are determined. The ground state spectra of the 13C and 34S isotopomers were assigned in natural abundance and heavy atom structure parameters are given.

Preferred Rotameric Conformations of Isobutyraldehyde, Their Dipole Moments and Vibrationally Excited States by Microwave Spectroscopy

1986 ◽  
Vol 41 (3) ◽  
pp. 483-490 ◽  
Author(s):  
O. L. Stiefvater
Keyword(s):  
Oxygen Atom ◽  
Excited States ◽  
Ground State ◽  
Dipole Moments ◽  
Microwave Spectroscopy ◽  
Centrifugal Distortion ◽  
Gauche Conformation ◽  
Vibrationally Excited ◽  
Trans Conformation ◽  
Centrifugal Distortion Constants

The earlier prediction of the preferred and the less stable rotameric conformations of isobutyraldehyde, (CH3)2CHCHO, has been confirmed experimentally by microwave spectroscopy. The compound exists mainly in a gauche conformation, in which one of the methyl groups is eclipsed by the oxygen atom, and the less stable rotamer is the trans conformation, in which the oxygen atom eclipses the isopropyl hydrogen.Ground state rotational constants (in MHz) and centrifugal distortion constants (in kHz), together with dipole moments (in D), are:Rotation spectra due to three torsionally excited states of each rotamer have been identified, along with satellites arising from CH3 internal rotation and CC2 wagging.

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.

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.

Analysis of Internal Rotation and Determination of the Heavy Atom Structure of anti-2,3-Dimethylthiirane by Fourier Transform Microwave Spectroscopy

1996 ◽  
Vol 51 (10-11) ◽  
pp. 1099-1106 ◽  
Author(s):  
Holger Hartwig ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Internal Rotation ◽  
Ground State ◽  
Heavy Atom ◽  
Microwave Spectroscopy ◽  
Rotational Spectrum ◽  
Advanced Technique ◽  
Fourier Transform Microwave Spectroscopy ◽  
Potential Parameters

Abstract We used the advanced technique of Fourier transform microwave spectroscopy to measure and assign the ground state rotational spectrum of anti-2,3-dimethylthiirane, and to analyse the internal rotation of the two methyl groups. The potential parameters obtained are V3 = 13.1678(21) and V12' = -1.6678(25) kJ/mol. The measurement and assignment of the 13C and 34S isotopomers in the ground state allowed to determine the molecular structure of the heavy atom frame using the Τs and Τ0 methods.

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.

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.

Vibronic Ground State Rotational Spectrum of 3-Bromothiophene

1983 ◽  
Vol 38 (11) ◽  
pp. 1238-1247 ◽  
Author(s):  
Dirk Hübner ◽  
Eckhard Fliege ◽  
Dieter H. Sutter
Keyword(s):  
Ground State ◽  
Coupling Constants ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Set Up ◽  
Centrifugal Distortion Constants

The rotational spectrum of 3-bromothiophene was investigated in the frequency range between 8 and 18 GHz by use of a microwave Fourier transform spectrometer. Both a- and b-type spectra were assigned for the vibronic ground state. Rotational constants, quartic centrifugal distortion constants and quadrupole coupling constants were obtained for the 79Br- and 81Br-isotopic species. For the analysis, the effective rotational Hamiltonian including centrifugal distortion in the form of Van Eijck's symmetric top reduction and bromine quadrupole coupling was set up in the coupled basis of the limiting symmetric top, J, K, I, F, MF>, and was diagonalized numerically. Spin rotation interaction was neglected

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.

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.

33S Nuclear Hyperfine Structure in the Rotational Spectrum of Thiazole

1993 ◽  
Vol 48 (12) ◽  
pp. 1219-1222 ◽  
Author(s):  
U. Kretschmer ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Molecular Beam ◽  
Microwave Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract We investigated the 33S nuclear quadrupole coupling of thiazole- 33S in natural abundance by molecular beam Fourier transform microwave spectroscopy. In addition the 14N nuclear quadrupole coupling could be analyzed with high precision. We derived the rotational constants A = 8529.29268 (70) MHz, B = 5427.47098 MHz, and C = 3315.21676 (26) MHz, quartic centrifugal distortion constants and the quadrupole coupling constants of 33S χaa = 7.1708 (61) MHz and χbb= -26.1749 (69) MHz and of 14N χ aa = -2.7411 (61) MHz and χbb = 0.0767 (69) MHz.

Sign in / Sign up

Export Citation Format

Share Document