Microwave Spectrum of Cyclohexene Sulfide

1973 ◽  
Vol 51 (4) ◽  
pp. 529-532 ◽  
Author(s):  
R. Kewley
Keyword(s):  
Excited States ◽  
Relative Intensity ◽  
Vibrational State ◽  
Heavy Atom ◽  
Microwave Spectrum ◽  
Cyclohexene Oxide ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Intensity Measurements

The microwave spectrum of cyclohexene sulfide (7-thiabicycIo[4,1,0]heptane) has been investigated in the 26.5–40 GHz region. R-branch lines due to both a- and c-type transitions have been assigned for the ground vibrational state and for the first excited states of the ring bending and ring twisting modes. From relative intensity measurements the frequencies of these two modes are estimated as: vbend = 115 ± 20 cm−1 and vtwist = 200 ± 60 cm−1. The rotational constants for the ground vibrational state are (in MHz): A = 3512.086 ± 0.010, B = 2057.969 ± 0.003, and C = 1623.023 ± 0.003. These values are consistent with a twisted half chair structure for the heavy atom skeleton of cyclohexene sulfide, similar to that of cyclohexene oxide.

scholarly journals Microwave Spectrum, Structure and Rotation-Vibration Interaction of Deutero-Fulminic Acid, DCNO

1969 ◽  
Vol 24 (12) ◽  
pp. 1973-1979
Author(s):  
Hans Karl Bodenseh ◽  
Manfred Winnewisser
Keyword(s):  
Vibrational State ◽  
Microwave Spectrum ◽  
Frequency Region ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Moments Of Inertia ◽  
Ground Vibrational State ◽  
Bending Modes ◽  
O 10 ◽  
Spectrum Structure

The microwave spectrum of the deuterated form of fulminic acid (DCNO) has been investigated in the frequency region from 9 to 42 GHz. For the ground vibrational state of DCNO the following rotational constants were obtained: B0(D12C14N16O) =10 292.50 MHz,B0(D13C14N18O) =10 011.66 MHz,B0(D12C14N18O) = 9 758.87 MHz. The corresponding moments of inertia yield a combined rs and r0 structure: rDC = 1.027 ±0.001 Å, rCN = 1·168 ±0.001 Å, rNO = 1.199 ± 0.001 Å. For the two degenerate bending modes ν4 and ν5 the l-type doublets of the transition J = 1 - 2 and the two corresponding series of l-type doubling transitions have been observed. The analysis of the two l-type doubling series revealed that P4 and P6 centrifugal distortion contributions are sufficient to account for the spectrum. The doubling constants given in MHz are q4 = 17.9103-(0.6467 · 10-4)J(J + 1) +(0.188 · 10-8) [J(J + 1)]2, q5 = 38.0907-(0.3061 · 10-3)J(J + 1) + (0.314 · 10-8)[J(J + 1) ]2. A third series of l-type doubling transitions arising from the II-level of the ν5=3 vibrational state has been found and analysed, yielding: q(0)3×5 =29.2748 ± 1.8 · 10-4 MHz; EΦ-EII=Δ ≅ 41 cm-1.

Microwave spectrum of trans-1-methoxy-1,3-butadiene

1977 ◽  
Vol 55 (19) ◽  
pp. 3480-3486 ◽  
Author(s):  
R. Kewley ◽  
S. C. Dass
Keyword(s):  
Vibrational State ◽  
Microwave Spectrum ◽  
The Other ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Microwave Spectra ◽  
Trans Conformer ◽  
Distortion Parameters

The microwave spectra of two conformers of 1-methoxy-1,3-butadiene have been studied in the 18 to 40 GHz region. One conformer is the s-trans conformer of trans-1-methoxy-1,3-butadiene. The other is most likely the corresponding s-cis conformer. The rotational constants for the ground vibrational state are (in MHz) s-trans: A = 24 524(16); B = 1336.51(1); C = 1277.76(1); s-cis: A = 12 642.73(23); B = 1607.61(1); and C = 1439.64(1). The centrifugal distortion parameters DJK and DJ have also been determined for each conformer.For the s-trans conformer two series of torsional satellites have been found which are assigned as O—CH torsion with frequency 60(20) cm−1 and =C—C= torsion, frequency 80(30) cm−1. For the s-cis conformer one series of satellites has been observed, which has been assigned to =C—C= torsion, of frequency 103(30) cm−1.

Microwave spectrum and conformation of tetrahydropyran

1969 ◽  
Vol 47 (8) ◽  
pp. 1289-1293 ◽  
Author(s):  
V. M. Rao ◽  
R. Kewley
Keyword(s):  
Dipole Moment ◽  
Vibrational State ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Chair Form ◽  
Principal Axes

The microwave spectrum of tetrahydropyran has been recorded in the region 8–40 GHz. The rotational constants of the molecule in its ground vibrational state are, in MHz, A = 4673.48 ± 0.05, B = 4495.02 ± 0.11, and C = 2601.31 ± 0.05. The dipole moment components are, in Debye units, μa = 1.53 ± 0.02, μc = 0.82 ± 0.02, and μ = 1.74 ± 0.03. The direction of μ with respect to the principal axes of rotation together with the rotational constants show that the observed spectrum is due to the chair form of tetrahydropyran.

Microwave spectrum of allyl cyanide (CH2=CHCH2CN)

1968 ◽  
Vol 46 (8) ◽  
pp. 959-962 ◽  
Author(s):  
K. V. L. N. Sastry ◽  
V. M. Rao ◽  
S. C. Dass
Keyword(s):  
Dipole Moment ◽  
Vibrational State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Effect Measurement ◽  
Rotational Constants ◽  
Molecular Dipole ◽  
Ground Vibrational State ◽  
Molecular Dipole Moment ◽  
Rotational Isomers

The microwave spectrum of allyl cyanide (3-butenonitrile) was studied in the region from 8 to 26 GHz. It was confirmed that this molecule exists in the two rotational isomers "cis" and "gauche". In the cis form, both a- and b-type transitions were assigned and the rotational constants in the ground vibrational state were calculated to be A = 11 323.01 + 0.08 MHz, B = 3739.20 ± 0.01 MHz, C = 2858.52 ± 0.01 MHz. The molecular dipole-moment components are μa = 3.26 ± 0.01 D, μb = 2.16 ± 0.05 D, and μt = 3.91 ± 0.03 D. For the gauche form, the a-type transitions were assigned and the rotational constants in the ground vibrational state are A = 17 295 MHz, B = 2619.91 ± 0.1 MHz, C = 2497.52 ± 0.1 MHz. The Stark effect measurement in this case gave the components of the dipole moment as μa = 3.69 ± 0.02 D, ub = 1.11 ± 0.06 D, μc = 0.98 ± 0.07 D, and μt = 3.98 ± 0.03 D.

Microwave Spectrum of 1,3-Dioxane

1972 ◽  
Vol 50 (11) ◽  
pp. 1690-1697 ◽  
Author(s):  
R. Kewley
Keyword(s):  
Dipole Moment ◽  
Vibrational State ◽  
Microwave Spectrum ◽  
Vibrational States ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Chair Form ◽  
Rotational Spectra

The microwave spectrum of 1,3-dioxane has been studied within the region 8 to 40 GHz. The rotational constants of the molecule in its ground vibrational state are, in MHz, A = 4999.94(0.05), B = 4807.61 (0.05), and C = 2757.12(0.05). The dipole moment components are, in Debye units, μb = 1.61 (0.02), μc = 1.29(0.01), and μ = 2.06(0.03). The values of the above quantities are consistent with a chair form structure. Rotational spectra due to five excited vibrational states of 1,3-dioxane have been assigned.

The Microwave Spectrum of Trifluoromethyl Hypofluorite

1974 ◽  
Vol 52 (6) ◽  
pp. 942-945 ◽  
Author(s):  
P. Buckley ◽  
J. P. Weber
Keyword(s):  
Electron Diffraction ◽  
Potential Barrier ◽  
Relative Intensity ◽  
Stark Effect ◽  
Dipole Moments ◽  
Double Resonance ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Intensity Measurements

The microwave spectrum of trifluoromethyl hypofluorite (CF3OF) has been analyzed in the region 8–40 GHz. Only μa R-type transitions were observed despite a careful search and using double-resonance techniques. These determine the following rotational constants: A = 5600 ± 100, B = 3108.13 ± 0.02, C = 3049.25 ± 0.02 MHz. The dipole moments determined from Stark effect measurements are μa = 0.30 ± 0.02, μb = 0.10 ± 0.06, μc = 0 D. The υ = 1 state of the CF3 torsion has also been measured; relative intensity measurements lead to a potential barrier of 3.9 kcal/mol, somewhat higher than the electron diffraction results.

scholarly journals The Microwave Spectrum of 3,4-Dihydro-1,2-Pyran

1985 ◽  
Vol 40 (9) ◽  
pp. 913-919
Author(s):  
Juan Carlos López ◽  
José L. Alonso
Keyword(s):  
Dipole Moment ◽  
Excited States ◽  
Ground State ◽  
Principal Axis ◽  
Microwave Spectrum ◽  
Average Intensity ◽  
Ring Conformation ◽  
Vibrationally Excited ◽  
Rotational Constants ◽  
Displacement Measurements

Abstract The rotational transitions of 3,4-dihydro-1,2-pyran in the ground state and six vibrationally excited states have been assigned. The rotational constants for the ground state (A = 5198.1847(24), B = 4747.8716(24) and C = 2710.9161(24) have been derived by fitting μa, μb and μc-type transitions. The dipole moment was determined from Stark displacement measurements to be 1.400(8) D with its principal axis components |μa| =1.240(2), |μb| = 0.588(10) and |μc| = 0.278(8) D. A model calculation to reproduce the ground state rotational constants indicates that the data are consistent with a twisted ring conformation. The average intensity ratio gives vibrational separations between the ground and excited states of the ring-bending and ring-twisting modes of ~ 178 and ~ 277 cm-1 respectively.

Millimeter Wave Rotational Transitions of 16O12C32S and 16O13C32S

1974 ◽  
Vol 29 (8) ◽  
pp. 1213-1215 ◽  
Author(s):  
N. W. Larsen ◽  
B. P. Winnewisser
Keyword(s):  
Excited States ◽  
Millimeter Wave ◽  
Vibrational Spectra ◽  
Vibrational State ◽  
Vibrational States ◽  
Ground Vibrational State ◽  
Wave Region ◽  
Rotational Transitions ◽  
Good Agreement

Rotational transitions of 16012C32S and 16013C32S in the ground vibrational state and of 16012C32S in several excited states have been accurately measured in the millimeter wave region for a minimum of four different J values. The analysis of the measured frequencies leads to rotational constants for the following vibrational states: 0 00 0 of 16O13C32S and 0 00 0, 0 1 1c 0, 0 1 1d 0, 0 20 0, 0 22c 0, 0 22d 0, 0 00 1 of 16O12C32S. Since the two components of the 0 22 0 transitions were resolved, an analysis of the l-type resonance was carried out and the interval 0 22 0 - 0 20 0 has been determined to be -4.63(10) cm-1. The result is in good agreement with the presently available determination of this level from vibrational spectra.

Elektrisches Dipolmoment und Mikrowellenrotationsspektrum des GeO und GeS

1969 ◽  
Vol 24 (8) ◽  
pp. 1217-1221 ◽  
Author(s):  
J Hoeft ◽  
F.J. Lovas ◽  
E Tiemann ◽  
R Tischer ◽  
T Törring
Keyword(s):  
Electric Dipole ◽  
Vibrational State ◽  
Stark Effect ◽  
Dipole Moments ◽  
Electric Dipole Moments ◽  
Rotational Constants ◽  
Ground Vibrational State ◽  
Rotational Spectra ◽  
Rotational Transitions

Stark-effect measurements on pure rotational transitions of GeO and GeS are described. Measurements on the ground vibrational state of the most abundant isotopic molecules resulted in the following electric dipole moments: 74Ge18O μ = (3,28±0,10) D; 74Ge32S μ = (2,00 + 0,06) D . Due to improved resolution and sensitivity of the spectrometer, the rotational spectra of GeS were measured in more detail and with greater accuracy than previously. The derived rotational constants, Y01 , Y11, Y21 and Y02 , are reported.

Microwave Spectrum of Acetyl Cyanide in the Ground and Excited States. I

1976 ◽  
Vol 31 (7) ◽  
pp. 840-846
Author(s):  
F. Scappini ◽  
H. Dreizler
Keyword(s):  
Internal Rotation ◽  
Excited States ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Torsion Vibration ◽  
Quadrupole Coupling ◽  
Rotation Parameters

Abstract The microwave spectra of acetyl cyanide, CH3COCN, in the ground and in the two lowest excited states have been investigated. The rotational constants and the quadrupole coupling constants have been evaluated for all these states. The internal rotation parameters have been refined with respect to previous works. Evidence for a rotation-torsion -vibration interaction has been found in the spectra of the excited states.

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