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

The Ground State Microwave Spectrum and Dipole Moment of 2-Isocyano-Propane

1989 ◽  
Vol 44 (7) ◽  
pp. 680-682 ◽  
Author(s):  
Michael Krüger ◽  
Helmut Dreizler
Keyword(s):  
Fourier Transform ◽  
Dipole Moment ◽  
Ground State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Total Dipole Moment ◽  
Rotational Constants ◽  
Centrifugal Distortion Constants

Abstract The ground state rotational spectrum of 2-isocyano-propane is assigned. The rotational constants and the quartic centrifugal distortion constants are determined by Microwave Fourier Transform (MWFT) Spectroscopy. The analysis of the Stark effect leads to a total dipole moment of 4.055(1) D.

Microwave Spectrum of Methane-d2, CH2D2

1975 ◽  
Vol 53 (19) ◽  
pp. 2023-2028 ◽  
Author(s):  
Eizi Hirota ◽  
Misako Imachi
Keyword(s):  
Dipole Moment ◽  
Microwave Spectrum ◽  
Normal Coordinate Analysis ◽  
Centrifugal Distortion ◽  
Normal Coordinate ◽  
Rotational Constants ◽  
Microwave Spectrometer ◽  
Rotational Transitions ◽  
Centrifugal Distortion Constants

Three rotational transitions of methane-d2 were observed by a source-modulation microwave spectrometer. The two differences in the rotational constants, A – C and B – C, were determined to be 37 555.758 and 13 664.280 MHz, respectively, from the observed frequencies of 110 ← 101 and 211 ← 202 after correcting for the centrifugal distortion effects. The centrifugal distortion constants were evaluated by a normal coordinate analysis. The dipole moment of CH2D2 was determined to be 0.014 ± 0.005 D, by comparing the intensity of 211 ← 202 with that of an oxygen line.

The Microwave Spectrum, Dipole Moment, and Structure of Glycidol

1975 ◽  
Vol 53 (15) ◽  
pp. 2247-2251 ◽  
Author(s):  
W. V. F. Brooks ◽  
K. V. L. N. Sastry
Keyword(s):  
Hydrogen Bonding ◽  
Dipole Moment ◽  
Hydrogen Atom ◽  
Microwave Spectrum ◽  
Centrifugal Distortion ◽  
Total Dipole Moment ◽  
Hindered Rotation ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Centrifugal Distortion Constants

The microwave spectra of glycidol [Formula: see text] and its deuterated (—OD) form have been studied in the range 8–40 GHz. The rotational (in MHz) and centrifugal distortion constants (in kHz) of glycidol are: A = 10 347.87, B = 4102.36, C = 3781.95; ΔJ = 2.38, ΔJK = −311, ΔK = 5.2, δJ = 0.3159, δK = −9.76. The rotational constants and distortion constants of glycidol (OD) are A = 10 010.31, B = 4056.73, C = 3717.02; ΔJ = 2.53, ΔJK = 197, ΔK = 7.7,δJ = 0.3532,δK = −7.19. The dipole moment components of the normal molecule in Debye units are μa = 0.61, μb = 1.20, μc = 0.52, and the total dipole moment is 1.44 D.A structure is derived with the alcoholic hydrogen atom close (2.5 Å) to the ring oxygen. The structure and the absence of signs of free or hindered rotation, can be accounted for by hydrogen bonding between the proton and the ring oxygen.

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.

Bromine Spin-Rotation Coupling Constants of Cyclopropylbromide-79Br and -81Br

1992 ◽  
Vol 47 (3) ◽  
pp. 507-510
Author(s):  
N. Heineking ◽  
J. Gripp ◽  
H Dreizler
Keyword(s):  
Fourier Transform ◽  
Fourier Transform Spectroscopy ◽  
Microwave Spectrum ◽  
Spin Rotation ◽  
Coupling Constants ◽  
Centrifugal Distortion ◽  
Rotational Constants ◽  
Diagonal Component ◽  
Quadrupole Coupling ◽  
Centrifugal Distortion Constants

AbstractWe reinvestigated the microwave spectrum of cyclopropylbromide with the increased resolution of pulsed microwave Fourier transform spectroscopy. Because of the higher frequency precision, it was possible to determine the spin-rotation coupling constants of bromine. Global fits of rotational constants, quartic centrifugal distortion constants, quadrupole coupling constants including the off-diagonal component χac , and spin-rotation coupling constants simultaneously to almost one hundred hyperfine components for each of the two bromine isotopomers resulted in overall standard deviations of well below 5 kHz

The Ground State Microwave Spectrum of 2-Fluoropropane

1988 ◽  
Vol 43 (2) ◽  
pp. 138-142 ◽  
Author(s):  
Michael Meyer ◽  
Helmut Dreizler
Keyword(s):  
Dipole Moment ◽  
Ground State ◽  
Stark Effect ◽  
Microwave Spectrum ◽  
Methyl Groups ◽  
Rotation Barrier ◽  
Centrifugal Distortion ◽  
Internal Rotation Barrier ◽  
The Moment ◽  
Centrifugal Distortion Constants

We determined the internal rotation barrier V3 = 3.285 kcal/mol (13.74 kJ/mol) and the moment of inertia Iα = 3.184 amuÅ2 of the methyl groups from the ground state microwave spectrum of 2-fluoropropane. Additionally the rotational constants, the quartic and some sextic centrifugal distortion constants are reported. The analysis of the Stark effect leads to the dipole moment 1.958 D.

The Microwave Spectrum of 15N-Difluoroacetonitrile: Electric Dipole Moment and Partial r0-Structure

1991 ◽  
Vol 46 (6) ◽  
pp. 535-539 ◽  
Author(s):  
Bettina Ohle ◽  
Heinrich Mäder ◽  
Antonio Guarnieri
Keyword(s):  
Dipole Moment ◽  
Electric Dipole Moment ◽  
Electric Dipole ◽  
Stark Effect ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Frequency Range ◽  
Rotational Constants ◽  
Principal Axes ◽  
Centrifugal Distortion Constants

AbstractThe rotational spectrum of 15N-difluoroacetonitrile has been investigated in the frequency range from 8 to 18 GHz. From the measured lines with J up to 20, rotational constants and quartic centrifugal distortion constants have been determined. For some lines the Stark effect has been examined, yielding the components of the electric dipole moment along the a- and c-principal axes of inertia. The obtained rotational constants were also used together with the rotational constants of the normal isotopomer to derive a partial restructure of the molecule

The Rotational Spectrum of the Fluorobenzene-Argon Van der Waals Complex

1992 ◽  
Vol 47 (5) ◽  
pp. 681-684 ◽  
Author(s):  
W. Stahl ◽  
J.-U. Grabow
Keyword(s):  
Fourier Transform ◽  
Molecular Beam ◽  
Van Der Waals ◽  
Argon Atom ◽  
Fourier Transform Spectrometer ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Ring Plane ◽  
Van Der Waals Complex ◽  
Centrifugal Distortion Constants

AbstractThe rotational spectrum of the fluorobenzene-argon complex has been studied in the microwave region between 7 and 18 GHz using a pulsed molecular beam microwave Fourier transform spectrometer. The rotational constants were found to be A = 1811.81369(11) MHz, B= 1105.12965(15) MHz, C = 901.84281(5) MHz, the centrifugal distortion constants are ΔJ = 2.6886(17) kHz, ΔJK = 8.3761 (52) kHz ΔJK= -8.278(5) kHz, ρJ, =0.65993(72) kHz, and ρK = 6.013(11) kHz. The argon atom is placed 3.55 Å above the ring plane

33S Nuclear Hyperfine Structure in the Rotational Spectrum of Thiazole

1993 ◽  
Vol 48 (12) ◽  
pp. 1219-1222 ◽  
Author(s):  
U. Kretschmer ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Molecular Beam ◽  
Microwave Spectroscopy ◽  
Coupling Constants ◽  
Rotational Spectrum ◽  
Centrifugal Distortion ◽  
Quadrupole Coupling ◽  
Nuclear Quadrupole ◽  
Centrifugal Distortion Constants

Abstract We investigated the 33S nuclear quadrupole coupling of thiazole- 33S in natural abundance by molecular beam Fourier transform microwave spectroscopy. In addition the 14N nuclear quadrupole coupling could be analyzed with high precision. We derived the rotational constants A = 8529.29268 (70) MHz, B = 5427.47098 MHz, and C = 3315.21676 (26) MHz, quartic centrifugal distortion constants and the quadrupole coupling constants of 33S χaa = 7.1708 (61) MHz and χbb= -26.1749 (69) MHz and of 14N χ aa = -2.7411 (61) MHz and χbb = 0.0767 (69) MHz.

The Microwave Spectrum of 2,6-Lutidine, Analysis of Internal Rotation and 14 N Hyperfine Structure

1993 ◽  
Vol 48 (11) ◽  
pp. 1093-1101 ◽  
Author(s):  
C. Thomsen ◽  
H. Dreizler
Keyword(s):  
Fourier Transform ◽  
Hyperfine Structure ◽  
Internal Rotation ◽  
Molecular Beam ◽  
Microwave Spectrum ◽  
Methyl Groups ◽  
Rotational Spectrum ◽  
Rotational Constants ◽  
Moments Of Inertia ◽  
Nuclear Quadrupole

Abstract The rotational spectrum of 2,6-lutidine, (CH3)2C5H3N, has been recorded between 6 and 26.5 GHz using pulsed molecular beam microwave Fourier transform spectroscopy. The rotational constants are A = 3509.7139(84) MHz, B = 1906.8639(101) MHz, and C = 1254.6215(14) MHz, the barrier to internal rotation of the two methyl groups is V3 = 1.1752 kJ/mol, their moments of inertia were found to be Iα = 3.0808(9) uÅ2 . The nitrogen nuclear quadrupole constants are χaa = +1.600(5) MHz, χbb = -4.572(3) MHz and χcc = +2.972(5) MHz.

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