Rotation-Torsion-Vibration Interaction in Acetyl Cyanide: Normal and 15N Isotopic Species

1978 ◽  
Vol 33 (2) ◽  
pp. 204-213 ◽  
Author(s):  
G. K. Pandey ◽  
H. Dreizler
Keyword(s):  
Excited State ◽  
Degrees Of Freedom ◽  
Rotational Spectrum ◽  
Vibrational States ◽  
Bending Vibration ◽  
Isotopic Species ◽  
Torsion Vibration ◽  
First Excited State ◽  
Rotational Transitions ◽  
Methyl Torsion

The rotation - torsion - vibration interaction in the normal and 15N isotopic species of Acetyl Cyanide is studied in the rotational spectrum of ground, first excited state of methyl torsion and first excited state of CCN in plane bending vibration. With respect to a previous -work [1] a more detailed check of a model with five degrees of freedom, comprising three for the overall rotation and two for the two lowest vibrations was possible. Potential parameters were fitted simultaneously to the splittings of the rotational transitions in the ground, excited torsional and excited vibrational states for the normal and 15N isotopic species of the molecule. The coefficients V3 and V6 of the Fourier expansion of the hindering potential for the torsion and two interaction constants V3c′ and F3c″ for the torsion and in plane CCN bending vibration were determined, apart from the harmonic force constant k2q for the vibration, which is obtained from the measured infrared data of the normal species. Using these results, the (E-A) splittings of the rotational transitions could be nicely reproduced but not the absolute frequencies of the rotational transitions.

Acetyl Cyanide II. Rotation–Torsion–Vibration Interaction in the Rotational Spectrum

1976 ◽  
Vol 31 (11) ◽  
pp. 1398-1407 ◽  
Author(s):  
F. Scappini ◽  
H. Mäder ◽  
H. Dreizler
Keyword(s):  
Excited States ◽  
Ground State ◽  
Degrees Of Freedom ◽  
Rotational Spectrum ◽  
Rotational Spectra ◽  
Torsion Vibration ◽  
First Excited State ◽  
Methyl Torsion ◽  
Theoretical Considerations ◽  
Internal Degrees Of Freedom

Abstract The rotation-torsion-vibration interaction in acetyl cyanide, CH3COCN, has been studied in the rotational spectra of the first excited state of the methyl torsion and of the CCN-in-plane bending. A model with two internal degrees of freedom has been used to account for the A-E rotational splittings in the ground state and in the two excited states simultaneously. The constants in the Fourier expansion of the potential hindering the methyl torsion are determined. The results are compared with those obtained in a previous work from the A-E rotational splittings of the ground state only, using a model with one degree of freedom. Group theoretical considerations are made upon the Hamiltonian used in the present analysis.

Rotation -Torsion -Vibration Interaction in the Rotational Spectra of Isotopic Species of Ethyl Cyanide

1976 ◽  
Vol 31 (10) ◽  
pp. 1228-1241 ◽  
Author(s):  
H. M. Heise ◽  
H. Mäder ◽  
H. Dreizler
Keyword(s):  
Degrees Of Freedom ◽  
Plane Deformation ◽  
Interaction Constant ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Torsion Vibration ◽  
Methyl Torsion ◽  
Potential Parameters

Abstract The measurements of the ground state rotational spectra of CH3CH2C15N and CH3CD2CN were extended to calculate the centrifugal distortion coefficients DJ , DJK and DK. The rotation-torsion-vibration interaction for these molecules including the normal species CH3CH2CN was studied in the rotational spectra of the first excited state of the methyl torsion and the CCN-in plane deformation. With respect to previous work a more detailed check of a model with five degrees of freedom comprising the overall rotation and the two lowest vibrations was possible. Potential parameters were fitted simultaneously to the splittings of the rotational transitions in the two lowest excited vibrational states of the three isotopic molecules. The coefficients V3 and V6 of the Fourier expansion of the hindering potential for the torsion and an interaction constant V'3c for the torsion and the CCN-in plane deformation were determined. Using these results it was possible to reproduce the frequencies of the torsional and CCN vibrations. With less success the torsional overtones could also be calculated.

Millimeter-Wave Spectrum of Ethyl Acetylene Centrifugal Distortion, Coriolis Interaction and Internal Rotation

1983 ◽  
Vol 38 (4) ◽  
pp. 447-451 ◽  
Author(s):  
J. Demaison ◽  
D. Boucher ◽  
J. Burie ◽  
A. Dubrulle
Keyword(s):  
Excited State ◽  
Internal Rotation ◽  
Plane Deformation ◽  
Wave Spectrum ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Coriolis Interaction ◽  
Methyl Group ◽  
First Excited State ◽  
Methyl Torsion

The rotational spectrum of ethyl acetylene has been investigated between 70 and 320 GHz. A Coriolis interaction has been found between the first excited state of the methyl torsion and the C - C = C in plane deformation. Splittings of transitions in the first excited torsional state show that the barrier hindering internal rotation of the methyl group amounts to 3271 cal/mole.

Vibrational Dependence in the Molecular G- and Susceptibility- Tensors of Sulfur Dioxide

1984 ◽  
Vol 39 (1) ◽  
pp. 63-65
Author(s):  
D. Hübner ◽  
D. H. Sutter
Keyword(s):  
Magnetic Susceptibility ◽  
Dipole Moment ◽  
Excited State ◽  
High Resolution ◽  
Small Amplitude ◽  
High Field ◽  
Zeeman Effect ◽  
Bending Vibration ◽  
Isotopic Species ◽  
First Excited State

The high field rotational Zeeman effect of SO2 molecules in the first excited state of the bending vibration has been studied under high resolution. Within the experimental uncertainties no υ-dependence is observed for the magnetic susceptibility anisotropies, and the observed υ-dependence in the g-tensor elements appears to be essentially caused by the υ-dependence of the rotational constants. If this finding may be generalized to all small amplitude vibrations, prospects for sign of the electric dipole moment determinations from rotational Zeeman effect studies of different isotopic species are brighter than expected hitherto.

Das Rotationsspektrum des JF/ Rotational Spectrum of IF

1973 ◽  
Vol 28 (9) ◽  
pp. 1405-1407 ◽  
Author(s):  
E. Tiemann ◽  
J. Hoeft ◽  
T. Törring
Keyword(s):  
Hyperfine Structure ◽  
Microwave Discharge ◽  
Rotational Spectrum ◽  
Vibrational States ◽  
Rotational Transitions

IF was produced by microwave discharge of l2 and C6F10(CFa)2. The rotational transitions J=0→1 and 1→2 in the vibrational states ν = 0, 1, 2 were observed. The analysis of the hyperfine structure yields the following hfs constants:127I: e qv Q = (-3440.89+5.47 (ν+½) ±0.20) MHz,cI = ( + 90 ±10) kHz.

Microwave Rotational Spectrum of Indium Monofluoride

1969 ◽  
Vol 24 (4) ◽  
pp. 634-636 ◽  
Author(s):  
F. J. Lovas ◽  
T. Törring
Keyword(s):  
Spin Rotation ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Coupling Constant ◽  
Vibrational States ◽  
Molecular Parameters ◽  
Microwave Rotational Spectrum ◽  
Quadrupole Coupling ◽  
Rotational Transitions

Abstract The rotational transitions J = 1 → 2 and 2 → 3 were measured in 115In19F. From these spectra the following molecular parameters have been determined: the Dunham-coefficients Y01, Y11 and Y02, the quadrupole coupling constants, eqQ, in the ν = 0 and v = 1 vibrational states as well as the spin-rotation coupling constant cIn.

Die Mikrowellen-Rotationsspektren des AgCl, AgBr und AgJ

1971 ◽  
Vol 26 (2) ◽  
pp. 240-244 ◽  
Author(s):  
J. Hoeft ◽  
F. J. Lovas ◽  
E. Tiemann ◽  
T. Törring
Keyword(s):  
Coupling Constants ◽  
Rotational Spectrum ◽  
Vibrational States ◽  
Molecular Constants ◽  
Quadrupole Coupling ◽  
Rotational Transitions

The observation of the low lying rotational transitions J = 0 →1 of AgCl and J = 2→3 of AgBr resulted in improved quadrupole coupling constants: 107, 109Ag35Cl: e qν Q (35Cl) = -36,50 (10) MHz (ν=0,1); 107.109Ag79Br; e q0 Q(79Br) =297,10(15) MHz, e q1 Q (79Br) =297,65 (15) MHz. In con­trast to former measurements of KRISHER and NORRIS we obtained the following constants of 107Ag79Br: Y01 = 1943,6420 (50) MHz, Y11 = -7,0745(70) MHz, re = 2,393100(29) Å. The unknown rotational spectrum of AgJ was found. Measurements of the transition J = 3 →4 in four vibrational states resulted in the determination of the following molecular constants: Y01 = 1345,1105(25) MHz, Y11= -4,2389(30) MHz, Y21 = 1,70(80) kHz, Y0,=-0,2540(2) kHz; re = 2,544611 (31) Å; e q0 Q(127J) =-1062,17(40) MHz, e q1 Q(127J) = -1064,81 (40) MHz.

scholarly journals Investigation of Ti -relaxation with a Microwave Pulse Spectrometer Rotational Lines of Formaldehyde and Sulfurdioxide

1979 ◽  
Vol 34 (11) ◽  
pp. 1330-1333 ◽  
Author(s):  
G. Bestmann ◽  
H. Dreizler ◽  
H. Mäder
Keyword(s):  
Pressure Dependence ◽  
Room Temperature ◽  
Microwave Pulse ◽  
Theoretical Calculations ◽  
Vibrational States ◽  
Time Resolved ◽  
Isotopic Species ◽  
Rotational Transitions

We discuss the features of a MW - pulse spectrometer as applied to time-resolved investigation of T2-relaxation of rotational transitions. The pressure dependence of 1/T2 of various transitions of formaldehyde, HCHO, and sulphurdioxide, SO2, has been studied at room temperature. Results are given for different isotopic species and vibrational states and compared with earlier linewidth studies and theoretical calculations

A Molecular Beam Microwave Fourier Transform (MB-MWFT) Spectrometer with an Electric Discharge Nozzle

1991 ◽  
Vol 46 (10) ◽  
pp. 914-916 ◽  
Author(s):  
J.-U. Grabow ◽  
N. Heineking ◽  
W. Stahl
Keyword(s):  
Fourier Transform ◽  
Excited State ◽  
Sulfur Dioxide ◽  
Ground State ◽  
Molecular Beam ◽  
Carbonyl Sulfide ◽  
Vibrational States ◽  
Nozzle Orifice ◽  
First Excited State ◽  
Electronic Ground

AbstractWe report on first experiments with our pulsed molecular beam microwave Fourier transform (MB-MWFT) spectrometer using a special nozzle which allows high voltage discharges within the nozzle orifice. Under these conditions we observed low J rotational transitions in highly excited vibrational states of carbonyl sulfide and sulfur dioxide, and also rotational lines of the SO radical in the 3Σ- electronic ground state and both the vibrational ground and first excited state.

Centrifugal Distortion Parameters of Fulminic Acid, HCNO, from the Millimeter-Wave Rotational Spectra

1971 ◽  
Vol 26 (1) ◽  
pp. 128-131 ◽  
Author(s):  
Manfred Winnewisser ◽  
Brenda P. Winnewisser
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Molecular Constants ◽  
Rotational Spectra ◽  
First Excited State ◽  
Bending Modes ◽  
Distortion Parameters

Abstract A newly designed millimeter-wave spectrometer has been employed for precise measurements of the millimeter-wave rotational spectrum of HCNO. Absorptions in several excited vibrational states as well as the ground state could be measured. The present paper presents the observed frequen­ cies and molecular constants obtained for the ground state and the first excited state of v4 and of v5, the vibrational bending modes

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