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Journal ArticleDOI

Electric Dipole Moments of Several Molecules from the Stark Effect

01 Feb 1953-Journal of Chemical Physics (American Institute of Physics)-Vol. 21, Iss: 2, pp 308-310
TL;DR: The following molecular electric dipole moments, in Debye units, have been obtained from the Stark effect of pure rotational spectra observed in the microwave region: 0.234±0.004 for NF3, 1.03±0,0.01 for PF3; 1.77± 0.06 for CH3CN; 3.83± 0.,3.00±0.,0.02 for HCN, 3.92± 0,2.
Abstract: The following molecular electric dipole moments, in Debye units, have been obtained from the Stark effect of pure rotational spectra observed in the microwave region: 0.234±0.004 for NF3; 1.03±0.01 for PF3; 1.77±0.02 for POF3; 3.00±0.02 for HCN; 3.92±0.06 for CH3CN; 3.83±0.06 for CH3NC; 1.79±0.02 for CH3F; 0.75±0.01 for CH3CCH; 1.26±0.01 for SiF3H. All values apply to the ground vibrational state.
Citations
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TL;DR: In this paper, the collision broadening of microwave rotational lines of linear rotators is discussed on the basis of Anderson's theory, restricted to first-order dipole-dipole interactions between the molecules.

3 citations

Journal ArticleDOI
TL;DR: In this paper, the molecular structure and conformational equilibrium of 1,2-diisocyano-ethane have been investigated using the gas electron-diffraction method, and two distinct conformers were identified, the low-energy anti form (56.9 ± 8.8%) and the higher energy gauche form (68.4 ± 4.9%).

3 citations

Journal ArticleDOI
TL;DR: The reaction of CH3NC with OH radicals was studied in smog chamber experiments employing PTR-ToF-MS and long-path FTIR detection and the atmospheric fate of methyl isocyanide is discussed.
Abstract: The reaction of CH3NC with OH radicals was studied in smog chamber experiments employing PTR-ToF-MS and long-path FTIR detection. The rate coefficient was determined to be kCH3NC+OH = (7.9 ± 0.6) × 10-11 cm3 molecule-1 s-1 at 298 ± 3 K and 1013 ± 10 hPa; methyl isocyanate was the sole observed product of the reaction. The experimental results are supported by CCSD(T*)-F12a/aug-cc-pVTZ//M06-2X/aug-cc-pVTZ quantum chemistry calculations showing the reaction to proceed primarily via electrophilic addition to the isocyanide carbon atom. On the basis of the quantum chemical data, the kinetics of the OH reaction was simulated using a master equation model revealing the rate coefficient to be nearly independent of pressure at tropospheric conditions and having a negative temperature dependence with kOH = 4.2 × 10-11 cm3 molecule-1 s-1 at 298 K. Additional quantum chemistry calculations on the CH3NC reactions with O3 and NO3 show that these reactions are of little importance under atmospheric conditions. The atmospheric fate of methyl isocyanide is discussed.

3 citations

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2 citations

References
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Journal ArticleDOI
TL;DR: A microwave spectrograph is described in which the absorption of the gas being studied is modulated by the application of a periodic Stark‐effect field so that the output of the crystal detector contains a radiofrequency component which can be amplified with a narrow‐band amplifier.
Abstract: A microwave spectrograph is described in which the absorption of the gas being studied is modulated by the application of a periodic Stark‐effect field so that the output of the crystal detector contains a radiofrequency component which can be amplified with a narrow‐band amplifier. By using a very narrow band‐width, achieved by employing phase‐sensitive detection, high sensitivity is obtained. The klystron is swept mechanically over the frequency range. Details of the components are given.

101 citations