The microwave spectrum, dipole moment, and structure of cyclopropyl carbinol

1970 ◽  
Vol 48 (19) ◽  
pp. 2949-2954 ◽  
Author(s):  
A. Bhaumik ◽  
W. V. F. Brooks ◽  
S. C. Dass ◽  
K. V. L. N. Sastry
Keyword(s):  
Hydrogen Bonding ◽  
Dipole Moment ◽  
Dipole Moments ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Rotational Isomers ◽  
Microwave Spectra ◽  
Strained Bonds ◽  
Hydroxyl Hydrogen

The microwave spectra of cyclopropyl carbinol [Formula: see text] and its deuterated (—OD) form were studied in the region of 8 to 35 gHz. Only one of the possible rotational isomers was identified. The measured rotational constants and dipole moments for C3H5CH2OH and C3H5CH2OD are, respectively, A (mHz): 12485.13, 12064.04; B (mHz): 3236.46, 3177.22; C (mHz): 2894.38, 2826.19; κ: −0.928665, −0.924001; μa (D): 1.81, 1.78; μb (D): 0.36, 0.32; μc (D): 0.31, 0.30; μtotal(D): 1.87, 1.84.Rotation is apparently hindered by hydrogen bonding between the hydroxyl hydrogen and the electrons in the strained bonds of the cyclopropyl ring.

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 and structure of phosphaethene, CH2=PH

1981 ◽  
Vol 34 (3) ◽  
pp. 465 ◽  
Author(s):  
RD Brown ◽  
PD Godfrey ◽  
D McNaughton
Keyword(s):  
Dipole Moment ◽  
Structural Parameters ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Moments Of Inertia ◽  
Microwave Spectra ◽  
Isotopic Species

The microwave spectra of phosphaethene (methylenephosphine) and five of its isotopic species have been observed and assigned in the region 5-125 GHz. Rotational constants and moments of inertia have been determined for 12CH2PH, 13CH2PH, 12CD2PD, 12CD2PH, (Z)-12CHDPH and (E)-12CHDPH. The moments of inertia have been used to determine the following structural parameters: rP-H= 1.425�; rC-P= 1.671�; rC-H,= 1.082�; <HCP(Z) = 124.5�; <HCP(E) = 119.1�; <CPH = 95.5�. The dipole moment components have been determined as �a = 0.7233(7) D and �b = 0.4657(ll) D.

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, Structure, and Dipole Moment of Cyanogen Azide, NCN3

1972 ◽  
Vol 50 (13) ◽  
pp. 1453-1457 ◽  
Author(s):  
C. C. Costain ◽  
H. W. Kroto
Keyword(s):  
Dipole Moment ◽  
Stark Effect ◽  
Structural Parameters ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Microwave Spectra ◽  
Isotopic Species ◽  
Planar Molecule ◽  
Spectrum Structure

The microwave spectra of cyanogen azide, NCN3, and two isotopic species have been investigated between 11 and 37 GHz. From the observed rotational constants, the following structural parameters have been obtained:[Formula: see text]The observed data are consistent with a planar molecule. The values of the rotational constants of the normal species are:[Formula: see text]The inertial defect for the normal species is 0.347 uÅ2.The dipole moment components have been determined from the Stark effect of several μa lines as μa = 2.93 ± 0.06 D and μb = 0.44 ± 0.015 D. The relatively low value of μb was responsible for the difficulty encountered in observing and assigning μb type transitions.

The microwave spectrum and structure of cyclopropyl carbinol. II. Four deuterated forms

1978 ◽  
Vol 56 (4) ◽  
pp. 530-532 ◽  
Author(s):  
W. V. F. Brooks ◽  
C. K. Sastri
Keyword(s):  
Dipole Moments ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Microwave Spectra

The microwave spectra of four deuterated species of cyclopropyl carbinol have been studied. The rotational constants A, B, and C (in MHz) are: C3H5CHaDbOH, 11 742.86, 3205.17, 2830.41; C3H5CDaHbOH, 11 853.44, 3188.10, 2878.28; C3H5CHaDbOD, 11 321.30, 3145.87, 2762.23; C3H5CDaHbOD, 11 433.85, 3129.30, 2809.81. The measured dipole moments of C3H5CHaDbOH and C3H5CHaDbOD are, respectively, 1.91 and 1.873 D. This confirms the essential details of the conformation proposed in an earlier paper.

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.

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

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.

The microwave spectrum of propynethial, HC≡C-CHS

1982 ◽  
Vol 35 (9) ◽  
pp. 1747 ◽  
Author(s):  
RD Brown ◽  
PD Godfrey ◽  
R Champion ◽  
M Woodruff
Keyword(s):  
Dipole Moment ◽  
Pyrolysis Product ◽  
Microwave Spectrum ◽  
Rotational Constants ◽  
Flash Pyrolysis ◽  
Resonance Structures ◽  
Alternative Structures ◽  
Isotopic Species

We have demonstrated that the flash pyrolysis of dipropargyl sulfide yields propynethial, HC≡CCHS, among the products. The microwave spectrum of the major isotopic species of propynethial and of HCCCH34S have been analysed. The derived rotational constants for these species enable us to eliminate any alternative structures for the pyrolysis product. The measured dipole moment components [μa = 1.763(1) D; μb = 0.661(1); μtotal = 1.883(1)] are discussed in terms of simple resonance structures.

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