Identification of Trace 2-Chloropropene with a New Chirped Pulse Microwave Spectrometer

Kisiel, Zbigniew; Kosarzewski, J.

doi:10.12693/aphyspola.131.311

Cited by 16 publications

(4 citation statements)

References 32 publications

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“…Multiple 20 μs free induction decays (FIDs) per gas pulse are collected as mentioned in previous literature, , allowing up to 100 million FIDs to be averaged in a single experiment. FIDs from multiple experiments are coadded on a separate computer and Fourier-transformed using Kisiel’s FFTS program available at the PROSPE Web site . Because of signal intensity and line width considerations, the Bartlett and Hanning Fourier transform windows were used for these experiments.…”

Section: Experimental Methodsmentioning

confidence: 99%

“…FIDs from multiple experiments are coadded on a separate computer and Fouriertransformed using Kisiel's FFTS program available at the PROSPE Web site. 10 Because of signal intensity and line width considerations, the Bartlett and Hanning Fourier transform windows were used for these experiments. Both of these windowing types produce full width at half-maximum (fwhm) line widths of 80 kHz and have an attributed uncertainty of 10 kHz in the line centers.…”

Section: Experimental Methodsmentioning

confidence: 99%

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Microwave Spectra and Structure of Ar–1,3-Difluorobenzene

et al. 2018

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The microwave spectrum of the dimer Ar-1,3-difluorobenzene from 2 to 18 GHz is reported. The spectrum has been observed using a chirped-pulse Fourier transform microwave (CP-FTMW) spectrometer that has recently been expanded to include the 2-6 GHz region of the electromagnetic spectrum. Details of this upgraded spectrometer are reported. Eighty-seven transitions were observed for the parent dimer spectrum, which was adequately fit to a semirigid rotational Hamiltonian consisting of A, B, and C as well as four quartic centrifugal distortion constants. Observations of C species in natural abundance were aided by utilizing smaller chirp ranges of 7-9 and 9-11 GHz for 1.9 million and 3.73 million averages, respectively. Assignment ofC isotopologues allowed for determination of the Kraitchman coordinates of the carbon atoms as well as inertial fits of the complex. The quantum-chemical structure predicts an Ar to monomer center of mass distance of 3.48 Å, compared with 3.564(1) Å determined from experimental structural analysis. This new study indicates that in fluorinated benzene-Ar dimers, when the fluorines are separated by more carbon atoms, the Ar-ring center distance decreases.

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Section: Experimental Methodsmentioning

confidence: 99%

Section: Experimental Methodsmentioning

confidence: 99%

Microwave Spectra and Structure of Ar–1,3-Difluorobenzene

et al. 2018

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“…It is expected that the geometries should remain the same upon substitution of 29 Si or 30 Si because the geometry should not depend on the number of neutrons. In 1,1-difluorosilacyclohex-2-ene, the angle is measured to be 108.1 (16) or 108.0 (11)°depending on if 29 Si or 30 Si is used, respectively. This is in good agreement with the theoretical value of 106.9°a nd is close to that of the common tetrahedral bond angle of 109.5°.…”

Section: The Journal Of Physicalmentioning

confidence: 99%

“…Approximately 100,000 20 μs FIDs was collected and averaged in each range for the samples except for 1,1-difluorosilacyclohex-2-ene where only 34,000 FIDs was collected before the sample was completely depleted. Fourier transformation of the FIDs was performed with Kisiel's FFTS program 16 using a Bartlett windowing function. A zoom-in view of portions of the spectra collected for both molecules is presented in Figures 3 and 4.…”

Section: ■ Introductionmentioning

confidence: 99%

Rotational Spectrum and Ring Structures of Silacyclohex-2-ene and 1,1-Difluorosilacyclohex-2-ene

Moon,

Duerden,

McFadden

et al. 2023

J. Phys. Chem. A

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Silacyclohex-2-ene and 1,1-difluorosilacyclohex-2-ene have been synthesized, and the chirped-pulse, Fourier-transform microwave spectra of each have been observed and analyzed from 4.9 to 23.1 GHz. Quantum chemical calculations have been performed at the B3LYP-D3BJ/Def2TZVP level of theory and predict μ a to be the largest dipole moment component with a significantly larger value in this component for 1,1-difluorosilacyclohex-2-ene. In accordance with this prediction, the spectra were predominantly a-type with the observation of a few b-and c-type transitions. The signalto-noise ratio was adequate in both spectra to observe 29 Si, 30 Si, and all singly substituted 13 C isotopologues in natural abundance. All spectra have been fit to a semirigid rotational Hamiltonian and are presented. Analysis of the physical meaning of the fitted parameters is explored and determined to hold for the rotational constants while being more empirical for the centrifugal distortion terms. Experimental structures of both molecules indicate that the quantum chemically calculated structures for the atoms in the ring are a very close depiction of the experimentally determined structures. The structures of each molecule are compared to similar molecules for context, where it is shown that both molecules possess a similar "half-chair" conformation to that of the all-carbon analogue, cyclohexene.

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