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.

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.

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.

The Centrifugally Induced Pure Rotational Spectrum and the Structure of Sulfur Trioxide. A Microwave Fourier Transform Study of a Nonpolar Molecule

1991 ◽  
Vol 46 (8) ◽  
pp. 710-714 ◽  
Author(s):  
Volker Meyer ◽  
Dieter Hermann Sutter ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Sulfur Trioxide ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Nonpolar Molecule ◽  
Centrifugal Distortion Constants ◽  
First Time

AbstractThe pure rotational spectrum of sulfur trioxide has been observed for the first time. A total of 25 high-J transitions could be assigned. The rotational constants, two quartic centrifugal distortion constants, and three sextic centrifugal distortion constants were determined as: B= 10 449.0667(23) MHz, C = 5216.0330(12) MHz, DJ = 9.2651 (18) kHz, DJK = -16.3922(18) kHz, HJ, = -8.8(34) • 10-3 Hz, HJK= -15.8(73) • 10-3 Hz, and HKJ = 34.2(73) • 10-3 Hz. An r0- and an re -structure are presented: r0= 1.4198(7) Å (calculated from B), r0 = 1.4210(7) Å (calculated from C), and re = 1.4175 Å

Reanalysis of the Nuclear Quadrupole Coupling in the Rotational Spectrum of N-Methylpyrrole

1994 ◽  
Vol 49 (11) ◽  
pp. 1063-1066
Author(s):  
S. R. Huber ◽  
A. Bauder
Keyword(s):  
Fourier Transform ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Least Squares Fit ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants ◽  
Pulsed Nozzle ◽  
Measured Transition

Abstract The rotational spectrum of N-methylpyrrole has been measured with pulsed nozzle Fourier transform microwave spectrometers between 6 and 38 GHz. The quadrupole hyperfine structure due to 14N has been reanalyzed in the A (m = 0) state o f the methyl internal rotation. Improved rotational constants, centrifugal distortion constants, and quadrupole coupling constants have been simultaneously determined from the measured transition frequencies in an iterative least-squares fit.

scholarly journals Tunable Diode Laser Spectra and Assignment of the 748 cm-1 Band of Propane

1989 ◽  
Vol 44 (4) ◽  
pp. 316-324 ◽  
Author(s):  
G. Gassler ◽  
B. Reißenauer ◽  
W. Hüttner
Keyword(s):  
Fourier Transform ◽  
Diode Laser ◽  
Ground State ◽  
Quantum States ◽  
Rotational Structure ◽  
Tunable Diode Laser ◽  
Ftir Spectrum ◽  
Centrifugal Distortion ◽  
Low Resolution ◽  
Centrifugal Distortion Constants

Abstract The rotational structure of the 748 cm-1 c-type CH2-rocking fundamental of propane was analysed using tunable diode laser (TDL) techniques. On grounds of a low-resolution Fourier transform (FTIR) spectrum and of the known ground-state rotational and centrifugal-distortion constants, some 700 transitions were measured and assigned in several regions of the band. The upper-state constants determined in this way allow the prediction of rovibrational frequencies to within 0.003 cm-1, covering quantum states up to J = 50 and Ka = 20. The band appears unperturbed.

The 33S Nuclear Hyperfine Structure in the Rotational Spectrum of Isothiazole

1994 ◽  
Vol 49 (11) ◽  
pp. 1059-1062
Author(s):  
J. Gripp ◽  
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 in the rotational spectrum of isothiazole 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 = 8275.51880(80) MHz, B = 5767.06181 (40) MHz, and C = 3396.85702(36) MHz, quartic centrifugal distortion constants, and the quadrupole coupling constants χaa (33S) = 8.7015 (57) MHz, χbb(33S) = -32.9696(60) MHz, χaa(14N) = 1.0732(47) MHz and χbb(14N) = -2.4753(46) MHz.

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.

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.

scholarly journals The Microwave Q-branch Spectrum of Germane in the Vibrational Ground State

1986 ◽  
Vol 41 (5) ◽  
pp. 747-751 ◽  
Author(s):  
W. Stahl ◽  
H. Dreizler ◽  
L. Jörissen ◽  
W. A. Kreiner
Keyword(s):  
Fourier Transform ◽  
Ground State ◽  
Spin Rotation ◽  
Subsequent Paper ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Vibrational Ground State ◽  
Spin Interactions ◽  
Centrifugal Distortion Constants

We present an analysis of the rotational spectra of 70GeH4, 72GeH4 and 74GeH4 in the vibrational ground state measured by microwave Fourier transform (MWFT) spectroscopy. All quartic, sextic and octic tensor centrifugal distortion constants have been determined. A discussion of spin-rotation and spin-spin interactions will be given in a subsequent paper.

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.

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