Sextische Zentrifugalverzerrungskonstanten und Mikrowellen-spektren bis 130 GHz von 12C32SF35Cl

1977 ◽  
Vol 32 (7) ◽  
pp. 754-760
Author(s):  
R. Hamm ◽  
H. Günther ◽  
W. Zeil
Keyword(s):  
Excited States ◽  
Energy Matrix ◽  
Centrifugal Distortion ◽  
Absolute Value ◽  
Degree Of Exactness ◽  
Symmetric Rotor ◽  
Energy Formula ◽  
Sufficient Degree ◽  
Set Up ◽  
Centrifugal Distortion Constants

Abstract It has been demonstrated that Watson's energy formula for the centrifugal distorted rotor is no longer sufficient for highly excited states. For the CSFCl molecule, the formula can only be used up to a limit of about J = 30. Beyond this rotational quantumnumber Watson's sextic Rotational Hamiltonian should be used for fitting the rotational energy parameters. Good results were obtained up to J = 70 using the sextic Hamiltonian and diagonalizing numerically the energy matrix set up in the rigid symmetric rotor basis. The sextic centrifugal distortion constants could be determined to a sufficient degree of exactness, i. e. the absolute value of the constants is considerably greater than the errors.

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.

scholarly journals Microwave Spectrum and Nuclear Quadrupole Interaction of 3-Bromothiophene in Excited Vibrational States

1983 ◽  
Vol 38 (12) ◽  
pp. 1309-1319 ◽  
Author(s):  
Yoshiaki Sasada
Keyword(s):  
Excited States ◽  
Nuclear Quadrupole Interaction ◽  
Coupling Constants ◽  
Vibrational Modes ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Rotational Spectra ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract The rotational spectra of 3-bromothiophene in the excited states of two vibrational modes were observed and the rotational constants, the centrifugal distortion constants, and the nuclear quadrupole coupling constants were determined. The wave numbers of the two vibrational modes were evaluated to be 210 cm-1 and 320 cm-1 by measuring relative intensities of the ground and excited vibrational transitions. Variations in the inertia defect for each of the vibrational modes are compared with the results of the approximate calculation.

Mikrowellenspektren schwingungsangeregter Zustände und allgemeines Valenzkraftfeld von 12C32SF35Cl / Microwave Spectra of Some Vibrational Excited States of 12C32SF35Cl

1978 ◽  
Vol 33 (5) ◽  
pp. 571-580 ◽  
Author(s):  
R. Hamm
Keyword(s):  
Force Field ◽  
Excited States ◽  
Internal Force ◽  
Equilibrium Structure ◽  
Vibration Frequencies ◽  
Centrifugal Distortion ◽  
General Internal ◽  
Microwave Spectra ◽  
Stretching Vibrations ◽  
Centrifugal Distortion Constants

The microwave spectra of some vibrational excited states of CSFC1 were measured with a conventional stark modulation spectrometer. As the spectra of the upper two stretching vibrations could not be found for lack of intensity, the equilibrium structure which had been estimated using Kuchitsu's procedure could not yet be determined. Nevertheless a general internal force field of CSFC1 was obtained, using the inertial defects of the measured excited states in the fit program NCA in addition to vibration frequencies and centrifugal distortion constants. Moreover, from the determined anharmonic part of the rotation vibration interaction constants, linear relations between some cubic force constants were established

Application of a PC-Controlled MW-Spectrometer for the Analysis of Ketene-D2. Simultaneous Analysis of Vibrational Excited States Using Microwave and Infrared Spectra

1989 ◽  
Vol 44 (6) ◽  
pp. 538-550 ◽  
Author(s):  
J. Doose ◽  
A. Guarnieri ◽  
W. Neustock ◽  
R. Schwarz ◽  
F. Winther ◽  
...  
Keyword(s):  
Excited States ◽  
Millimeter Wave ◽  
Infrared Spectra ◽  
Personal Computer ◽  
Room Temperature ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Ft Ir ◽  
Centrifugal Distortion Constants ◽  
Wave Spectrometer

D2CCO has been investigated in the first excited vibrational states of the ν9, ν6, and ν5 vibrations. About 150 transitions have been measured partly at room temperature and partly at 360 K using a micro- and millimeter-wave spectrometer provided with an averaging system using a personal computer. Rotational and centrifugal distortion constants have been obtained for the excited states mentioned. A simultaneous least squares analysis of these MW-data with upper state combination differences obtained from FT-IR data has been carried out. Improved sets of molecular parameters have been obtained.

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.

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

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