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 Centimeter and Millimeter Microwave Spectrum of 1,1-Difluoro-2-Chloroethylene

1993 ◽  
Vol 48 (3) ◽  
pp. 514-518 ◽  
Author(s):  
Luis A. Leal ◽  
J. C. López ◽  
J. L. Alonso ◽  
A. Guarnieri
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Coupling Analysis ◽  
Rotational Spectra ◽  
First Order ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants

Abstract The rotational spectra of both 35Cl and 37Cl 1,1-difluoro-2-chloroethylene isotopomers have been measured in the frequency range 12-225 GHz. A first order quadrupole coupling analysis has been performed for both isotopic species. The calculated quadrupole coupling constants for the 37Cl species not previously reported are χaa = - 49.2 (2), χbb = 14.2 (1), and χcc = 28.7 (1). Accurate rotational constants, quartic and some sextic centrifugal distortion constants have also been determined for both isotopomers from the fit to the observed central frequencies.

Microwave spectrum and molecular structure of silacyclopropenylidene c-C2H2Si

1994 ◽  
Vol 72 (11-12) ◽  
pp. 1206-1212 ◽  
Author(s):  
Mitsuaki Izuha ◽  
Satoshi Yamamoto ◽  
Shuji Saito
Keyword(s):  
Microwave Spectrum ◽  
Frequency Region ◽  
Spectral Lines ◽  
Absorption Cell ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Rotational Spectra ◽  
Isotopic Species ◽  
Microwave Spectrometer ◽  
Centrifugal Distortion Constants

The rotational spectra of silacyclopropenylidene, c-C2H2Si, and its isotopic species (C2H229Si, C2D2Si, 13C2H2Si) were observed in the frequency region of 220–400 GHz by using a source-modulated microwave spectrometer combined with a free space absorption cell. c-C2H2Si was produced in the cell by discharging a mixture of SiH4, C2H2, and He. Least-squares analyses of the observed spectral lines yielded the rotational constants and the centrifugal distortion constants for the normal and its isotopic species. From the observed rotational constants, the rs structure was determined: rs (C=C) = 1.3458 Å, rs (C—Si) = 1.8200 Å rs (C—H) = 1.0795 Å, and [Formula: see text]. (1 Å = 10−10 m.)

Microwave Spectrum of hexa-Deutero Dimethyl Selenide in the Ground and Excited Torsional States

1976 ◽  
Vol 31 (3-4) ◽  
pp. 357-361 ◽  
Author(s):  
G. K. Pandey ◽  
H. Dreizler
Keyword(s):  
Mean Value ◽  
Microwave Spectrum ◽  
Least Square ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Least Square Fit ◽  
Barrier Parameter ◽  
Dimethyl Selenide ◽  
The Mean ◽  
Centrifugal Distortion Constants

The ground state rotational spectra of 80Se and 78Se species of the hexadeutero dimethyl selenide have been measured in the region from 5 to 40 GHz. In both the cases, rotational and centrifugal distortion constants have been determined by a least square fit to about thirty transition frequencies. For the (CD3)2 80Se molecule, fourteen rotational transitions in the excited torsional states ṽ = l1, and ṽ = l2 were also recorded, out of which nine appeared as well resolved triplets. The potential barrier parameter V3 and the angle a between one of the ‘top axes’ and the ‘b axis’ have been determined by a least square fit of the mean value of the observed splittings in the ṽ = l1 and l2 states. The methyl top moment of inertia Iα was kept fixed at 6.35 amu Å2 , which is half of the observed inertia defect in the molecule.

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

Mikrowellenspektrum und rotationsspektroskopische Konstanten der Methylchlorsilane: CH3SiH2Cl, CH3SiD2Cl und CD3SiD2Cl / Microwave Spectrum and Rotational Spectroscopic Constants of Methyl-chloro-silane: CH3SiH2Cl, CH3SiD2Cl and CD3SiD2Cl

1975 ◽  
Vol 30 (11) ◽  
pp. 1441-1446
Author(s):  
W. Zeil ◽  
W. Braun ◽  
B. Haas ◽  
H. Knehr ◽  
F. Rückert ◽  
...  
Keyword(s):  
Microwave Spectrum ◽  
Coupling Constants ◽  
Spectroscopic Constants ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

The microwave spectra of the following isotopic species of Methyl-chloro-silane: CH3SiH2Cl, CH3SiD2 and CD3SiD2Cl have been measured and the rotational spectroscopic constants (rotational constants, centrifugal distortion constants and nuclear quadrupole coupling constants) have been determined

Effects of Centrifugal Distortion and Nuclear Quadrupole Coupling in the Microwave Spectrum of Vinyl Chloride

1971 ◽  
Vol 49 (2) ◽  
pp. 255-264 ◽  
Author(s):  
M. C. L. Gerry
Keyword(s):  
Vinyl Chloride ◽  
Microwave Spectrum ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
First Order ◽  
Isotopic Species ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants ◽  
Infrared Data

Both a- and b-type rotational transitions have been measured up to J = 30 for the two most abundant isotopic species of vinyl chloride, in the frequency region 8–18 GHz. These have enabled refinement of the rotational and chlorine nuclear quadrupole coupling constants, and evaluation of all first order centrifugal distortion constants. From the quadrupole coupling constants it is concluded that the field gradient around the C—Cl bond is somewhat more symmetric than previously reported. A comparison is made between the centrifugal distortion constants obtained from the microwave spectrum and those calculated using infrared data.

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.

The Microwave Spectrum of the Thiophene-Argon van der Waals Complex

1993 ◽  
Vol 48 (11) ◽  
pp. 1107-1110 ◽  
Author(s):  
U. Kretschmer ◽  
W. Stahl ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Molecular Beam ◽  
Argon Atom ◽  
Microwave Spectrum ◽  
Centrifugal Distortion ◽  
Ring Plane ◽  
Rotational Spectra ◽  
Van Der Waals Complex ◽  
Centrifugal Distortion Constants ◽  
Wave Spectrometer

Abstract The rotational spectra of the 32S-and 34S-thiophene-argon complex have been studied in the microwave region between 6 and 18 GHz using a pulsed molecular beam Fourier transform micro-wave spectrometer. The rotational and centrifugal distortion constants of the 32S-thiophene-argon complex were found to be A = 3280.38865(15) MHz, B = 1203.32018(15) MHz, C = 1123.45120(11) MHz, ΔJ = 3.3311 (33) kHz, ΔJK = 16.9015(31) kHz, ΔK = -18.302(14) kHz, δj = 0.235074(86) kHz, δK = 4.340(33) kHz. For the 34S-isotopomer A = 3231.16878(15) MHz, B = 1194.05602(58) MHz and C = 1109.53497(30) MHz with almost the same centrifugal distortion constants were obtained. The argon atom is placed 3.59 Å above the ring plane.

Ground State Centrifugal Distortion Constants of Trans-Acrolein, CH2 = CH — CHO from the Microwave and Millimeter Wave Rotational Spectra 1,2

1975 ◽  
Vol 30 (8) ◽  
pp. 1001-1014 ◽  
Author(s):  
Manfred Winnewisser ◽  
Gisbert Winnewisser ◽  
T. Honda ◽  
E. Hirota
Keyword(s):  
Ground State ◽  
Vibrational State ◽  
Line Search ◽  
Frequency Region ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Rotational Spectra ◽  
Measured Absorption ◽  
Centrifugal Distortion Constants ◽  
Line Positions

Abstract The pure rotational spectrum of trans-acrolein in the ground vibrational state has been assigned in the frequency region from 8 GHz to 180 GHz. The measured absorption lines encompass a-type transitions from the qRK, qQ1, qQ2 branches and 6-type transitions from the rP0, rP1, rP2, rR0 brandies for values of J up to 23. The rotational constants have been refined and all quartic and sextic centrifugal distortion constants have been determined using Watson's reduced Hamiltonian. This information has been used to predict line positions of astrophysical interest to warrant the interstellar line search for trans-acrolein.

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