Theoretical Study of Rotational Spectroscopy of Acetonitrile-d3in the Ground and Different Excited Vibrational States

2008 ◽  
Vol 5 (2) ◽  
pp. 201-218
Author(s):  
Motamedi Masoud ◽  
Moradi Parinaz
Keyword(s):  
Least Squares ◽  
Millimeter Wave ◽  
Theoretical Study ◽  
Rotational Spectroscopy ◽  
Accuracy Analysis ◽  
Centrifugal Distortion ◽  
Vibrational States ◽  
Rotational Spectra ◽  
Centrifugal Distortion Constants

The millimeter-wave rotational spectra of the ground and excited vibrational states v8= 1 and v8= 2 of the symmetric top molecule CD3CN have been analyzed again. Thel= ± 1 in v8=1,l= 0 andl= ± 2 series in v8= 2 states have been assigned respectively. The assignment and analysis of the measurements with a least – squares procedure have made it possible to obtain the rotational, quartic and sextic centrifugal distortion constants with more reliable and higher accuracy. Analysis of the v8= 2 state gave the following rotational parameters: Aζ = 62218.96 MHz and xll= 87527.70 MHz. Investigation in v8= 2 state indicates thatl-resonance is observed for this molecule aroundk=xℓℓ+(A−B)−2AζAζ−(A−B)≈4.

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.

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.

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

Microwave Spectrum and Barrier to Internal RotationinCH3COC15N

1977 ◽  
Vol 32 (7) ◽  
pp. 761-764 ◽  
Author(s):  
G. K. Pandey ◽  
H. Dreizler
Keyword(s):  
Least Squares ◽  
Potential Barrier ◽  
Ground State ◽  
Microwave Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Least Squares Fit ◽  
Barrier Parameter ◽  
Centrifugal Distortion Constants

Abstract The ground state rotational spectra of the 15N isotopic species of acetyl cyanide have been measured in the region from 8 to 40 GHz. The rotational and centrifugal distortion constants have been determined by a least squares fit to about 38 transition frequencies with J ≦ 14. The potential barrier parameter V3 and the angle a between the top axis and the 'a-axis' have been determined by a least squares of the (A-E) splittings of about 27 transitions. The methyl top moment of inertia was fixed at 3.14 amu Å2

The Rotational Spectrum of Monothioformic Acid. I. cis-and trans-HC(:O)SH1,2

1976 ◽  
Vol 31 (5) ◽  
pp. 422-437
Author(s):  
William H. Hocking ◽  
Gisbert Winnewisser
Keyword(s):  
Frequency Region ◽  
Absorption Lines ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Astrophysical Interest ◽  
Rotational Spectra ◽  
Measured Line ◽  
Centrifugal Distortion Constants ◽  
Cis And Trans ◽  
Line Positions

Abstract The rotational spectra of the two abundant isomers of monothioformic acid, cis- and trans- HC(:O)SH, have been assigned in the frequency region 8 -250 GHz. Over 90 a-type transitions and over 60 b-type transitions have been measured for each rotamer. The a-type transitions belong to the qRK , qQ1, qQ2, qQ3 and qQ4 branches and the b-type absorption lines encompass the Ka = 1 - 0, 2 - 1, 3 - 2, 4 - 3 and 5 - 4 rotational sub-bands. The rotational constants and all quartic and sextic centrifugal distortion constants have been determined for each rotamer using Watson's reduced Hamiltonian. In addition to the measured line positions the frequencies of some selected low-J transitions, not observed in this work but of potential astrophysical interest, have been listed as an aid in the interstellar search for monothioformic acid.

Millimetre wave spectrum of methyl mercaptan

1980 ◽  
Vol 58 (11) ◽  
pp. 1640-1648 ◽  
Author(s):  
R. M. Lees ◽  
M. Ali Mohammadi
Keyword(s):  
Interstellar Medium ◽  
Least Squares ◽  
Wave Spectrum ◽  
Methyl Mercaptan ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Millimetre Wave ◽  
Torsion Vibration ◽  
Vibration Rotation ◽  
Centrifugal Distortion Constants

An investigation of the rotational spectrum of CH332SH, one of the most recent molecules to be detected in the interstellar medium, has been carried out over the 25–107 GHz region. The frequencies of a-type Δk = 0 R-branch transitions have been measured for the J = 1 ← 0 up to J = 4 ← 3 multiplets for torsional states νt = 0–3. In addition, many P-, Q-, and R-branch transitions with Δk ≠ 0 have been identified in order to provide a catalogue of lines for potential radio astronomical applications. Improved values of rotational and centrifugal distortion constants, a-type torsion–vibration–rotation interaction constants, and torsional barrier parameters (V3 = 444.76 cm−1; effective V6 = −2.07 cm−1) have been determined from least-squares analyses of the spectra.

scholarly journals Millimeter Wave Spectrum and Centrifugal Distortion Analysis of Difluorochloromethane CHF2Cl in the Ground State

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1165-1168 ◽  
Author(s):  
R. Spiehl ◽  
A. Guarnieri
Keyword(s):  
Millimeter Wave ◽  
Ground State ◽  
Wave Spectrum ◽  
Sixth Order ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Vibrational Ground State ◽  
Distortion Analysis

Abstract The rotational spectra of CHF235Cl and CHF237Cl (CFC22) in the vibrational ground state between 42 and 214 GHz are reported. A centrifugal distortion analysis up to the sixth order is carried out.

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