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

The microwave spectrum of the ClS2 free radical

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1043-1050 ◽  
Author(s):  
Masaharu Fujitake ◽  
Eizi Hirota
Keyword(s):  
Free Radical ◽  
Force Field ◽  
Electronic Spectroscopy ◽  
Spin Rotation ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Harmonic Force ◽  
Isotopic Species ◽  
Spin Resonance ◽  
Centrifugal Distortion Constants

The rotational spectrum of the ClS2 free radical in the gaseous phase has been observed in the millimetre- and submillimetre-wave regions. The ClS2 radical was generated by a dc glow discharge in either S2Cl2 or SCl2. Both a- and b-type R-branch transitions, most of which were split into two fine structure components, were detected for both of the 35Cl and 37Cl isotopic species in the ground vibronic state. As expected from the small hyperfine interaction constants reported by an electron spin resonance (ESR) study, the hyperfine structure was resolved for none of the transitions observed in the present study. Analysis of the observed transition frequencies yielded rotational and centrifugal distortion constants and also spin–rotation interaction constants with their centrifugal corrections. The spin–rotation interaction constants obtained in the present study were consistent with g values of the ESR study. The rotational constants of the two isotopic species led to the structure parameters r(S—S) = 1.906 (7) Å, r(S—Cl) = 2.071 (5) Å, and θ(SSCl) = 110.3 (4)°. A harmonic force field was derived from the observed centrifugal distortion constants and inertial defects combined with the ν1 frequency reported in literature on electronic spectroscopy. This harmonic force field yielded the ν2 and ν3 frequencies (445 (21) and 213.0 (2) cm−1, respectively, for 35ClS2), which differed considerably from the values reported previously.

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.

Mikrowellenspektrum von 12C34SF37Cl

1976 ◽  
Vol 31 (6) ◽  
pp. 594-601 ◽  
Author(s):  
R. Hamm ◽  
H. J. Kohrmann ◽  
H. Günther ◽  
W. Zeil
Keyword(s):  
Equilibrium Structure ◽  
Microwave Spectrum ◽  
Natural Abundance ◽  
Least Square ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Isotopic Species ◽  
Planar Molecule ◽  
Least Square Fit ◽  
Centrifugal Distortion Constants

The microwave spectrum of the isotopic species 12C34SF37Cl has been measured in natural abundance. The three rotational constants and five quartic centrifugal distortion constants have been determined by a least square fit. In comparison with our former calculations, the five structural r0-parameters of the planar molecule have now been determined from eight rotational constants instead of six, thus yielding remarkably smaller confidence intervalls. Furthermore an re-structure has been calculated and an equilibrium-structure has been estimated

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.

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