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.

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.

Microwave Spectrum and Dipole Moment of Methylenecyclobutenone

1974 ◽  
Vol 29 (10) ◽  
pp. 1498-1500 ◽  
Author(s):  
W. Czieslik ◽  
L. Carpentier ◽  
D. H. Sutter
Keyword(s):  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Ground State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Least Square ◽  
Rotational Constants ◽  
Vibrational Ground State ◽  
Least Square Fit

Abstract The microwave spectrum of Methylenecyclobutenone has been investigated in the vibrational ground state in the range of 8 to 26.5 GHz. From a least square fit of 12 lines with J ≦ 4 the rotational constants have been calculated as A =5.775664±0.000009 GHz, B = 4.312314 ± 0.000007 GHz, C = 2.467814±0.000008 GHz. The inertia defect Δ = - 0.09 amuÅ2 indicates that the molecule is planar. From Stark-effect measurements the components of the molecular electric dipole moment were obtaied as |μa| = 2.04 ± 0.02 D, |μb| = 2.70±0.03 D, |μtotal| = 3.39 ± 0.05 D.

The Microwave Spectrum and Dipole Moment of Hexafluoropropanone

1991 ◽  
Vol 46 (3) ◽  
pp. 229-232 ◽  
Author(s):  
J.-U. Grabow ◽  
N. Heineking ◽  
W. Stahl
Keyword(s):  
Fourier Transform ◽  
Dipole Moment ◽  
Molecular Beam ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Fourier Transform Spectrometer ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Centrifugal Distortion Constants

AbstractWe recorded the microwave spectrum of hexafluoropropanone between 7 and 15 GHz using a pulsed molecular beam microwave Fourier transform spectrometer. The rotational constants were determined to be A = 2181.71980(14) MHz, B= 1037.22930(7) MHz, C = 934.89233(8) MHz, the quartic centrifugal distortion constants are D'J= 0.07378 (39) kHz, D'JK = 0.10002(75) kHz, D'K = -0.07269(266) kHz, δ'J = 0.00623(29) kHz and R' 6= 0.00755(12) kHz. Stark effect measurements yielded a dipole moment μ = μb= 0.3949 (18) D

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 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 and Dipole Moment of Dimethylnitrosamine

1972 ◽  
Vol 27 (8-9) ◽  
pp. 1329-1330 ◽  
Author(s):  
F. Scappini ◽  
A. Guarnieri ◽  
H. Dreizler ◽  
P. Rademacher
Keyword(s):  
Dipole Moment ◽  
Electron Diffraction ◽  
Internal Rotation ◽  
Microwave Spectrum ◽  
Rotational Constants

Abstract The microwave spectrum of the (CH3)2NNO and (CH3)215N15NO species have been studied and the rotational constants evaluated. By comparison of the inertia defects of the two species it can be stated that the nuclear frame of the molecule is planar, which is in agreement with the reported electron diffraction results. The dipole moment of the (CH3)215 N15NO species has been determined. Further studies on the internal rotation of the two methyl tops are in progress together with the analysis of the spectra of other isotopically substitued species.

Mikrowellenspektrum, interne Rotation, Struktur und Dipolmoment von Methylchloroform

1968 ◽  
Vol 23 (2) ◽  
pp. 307-311
Author(s):  
R. Holm ◽  
M. Mitzlaff ◽  
H. Hartmann
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Equilibrium Configuration ◽  
Structural Parameters ◽  
Microwave Spectrum ◽  
Methyl Group ◽  
Intensity Measurements ◽  
Isotopic Species ◽  
Asymmetric Top ◽  
Torsional Isomers

The microwave spectrum of several symmetric and asymmetric top isotopic species of CH3CCl3 has been studied in the region from 8 to 40 GHz. A least squares analysis of the rotational con-stants gave the following structural parameters :dC-C =(1.541 ±0.001) A, dC-Cl = (1,7712 ± 0.0008) A, dC-H = (1.090 ± 0.002) A, ∢H—C—H= (110.04±0.25) ° , ∢Cl—C—Cl= (109.39 ±0.25) ° .A dipole moment of μ = (1.755 ± 0.015) D has been derived from the investigation of the Stark effect of the transition J=4→5 of CH3CCl3335. From intensity measurements the barrier to internal rotation is estimated to be (1740 ± 300) cal/mol. An analysis of the spectrum of CH2DCCl2Cl37 shows conclusively that methylchloroform in its equilibrium configuration has the methyl group staggered with respect to the CCl3-group. It could be shown that there exist two torsional isomers gauche and anti with specific microwave spectra.

Elektrisches Dipolmoment und Mikrowellenrotationsspektrum von SnO, SnS, PbO und PbS

1969 ◽  
Vol 24 (8) ◽  
pp. 1222-1226 ◽  
Author(s):  
J Hoeft ◽  
F 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 SnO, SnS, PbO, and PbS are described. Measurements on the ground vibrational state of the most abundant molecules resulted in the following electric dipole moments: 120Sn16O: μ0= (4,32 ± 0,10) D, 120Sn32S: μ0= (3,18 ±0,10) D,208Pb16O: μ0 = (4,64 ± 0,30) D, 208Pb32S : μ0 = (3,59 ± 0,10) D. Due to improved resolution and sensivity of the spectrometer, the rotational spectra of SnS and PbS were measured in more detail and with greater accuracy than previously. The derived rotational constants, Y01, Y11, Y21, Y31 and Y02, are reported.

Double Resonance Modulation as a Standard Technique in Microwave Spectroscopy II. Line Shape and Integrated Intensity

1975 ◽  
Vol 30 (12) ◽  
pp. 1756-1764
Author(s):  
Otto L. Stiefvater
Keyword(s):  
Stark Effect ◽  
Double Resonance ◽  
Standard Technique ◽  
Microwave Spectroscopy ◽  
Pump Radiation ◽  
Absolute Value ◽  
Line Shapes ◽  
Intensity Measurements ◽  
Integrated Intensity

Abstract It is shown that there occur two easily distinguishable line shapes in DRM spectroscopy. These reflect the change of the integrated intensity of the signal transition when pump radiation is applied. They readily permit deductions concerning the position of the shared energy level. This result is useful for the analysis of complicated spectra, as is illustrated with examples.An expression is derived which permits the determination of the integrated intensity of absorption lines by DRM techniques alone. It does not require knowledge of the absolute value of the pump power and provides, therefore, a convenient basis for relative intensity measurements without recurrence to Stark effect modulation.

Microwave Spectra of Furazan. IV. Rotation Spectra of Vibrationally Excited States of Perdeuterated Furazan

1990 ◽  
Vol 45 (9-10) ◽  
pp. 1131-1143
Author(s):  
Otto L. Stiefvater
Keyword(s):  
Ir Spectroscopy ◽  
Excited States ◽  
Relative Intensity ◽  
Ground State ◽  
Double Resonance ◽  
Microwave Spectroscopy ◽  
Vibrationally Excited ◽  
Pure Rotation ◽  
Intensity Measurements ◽  
Modes Of Vibration

Abstract The pure rotation spectra of molecules in 25 vibrationally excited states of perdeuterated furazan, C2D2N2O, have been studied by double resonance modulation (DRM) microwave spectroscopy. Twelve of these spectra have been correlated, -on the basis of relative intensity measurements under DRM -, with fundamental vibrations as previously established by IR spectroscopy. Rotational parameters for these 12 fundamental levels are reported, and the contributions to the effective rotational constants and to the inertia defect of the ground state of d2 -furazan have been determined for 10 modes of vibration.

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