Overview of High-Resolution Infrared Measurement and Analysis for Atmospheric Monitoring of Halocarbons

McNaughton, Donald; Robertson, Evan G.; Thompson, Christopher D.; Chimdi, Tarekegn; Bane, Michael; Appadoo, D.R.T.

doi:10.1021/ac101425d

Cited by 24 publications

(16 citation statements)

References 89 publications

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“…Remote sensing is a valuable tool for detecting and monitoring the composition of the Earth's atmosphere as well as for probing the molecular content of interstellar clouds or the atmospheres of solar and extra-solar objects [1][2][3][4][5][6][7][8] . The successful analysis of at-mospheric and astrophysical spectra and the reliability of the retrieved concentrations and temperature profiles however strongly depend on the accuracy of available spectroscopic parameters, such as the positions, intensities, and pressure broadening and shifting coefficients of spectral lines.…”

Section: Introductionmentioning

confidence: 99%

Self and N2 collisional broadening of rovibrational lines in the ν6 band of methyl iodide (12CH3I) at room temperature: The J and K dependence

Attafi

Hassen

Aroui

et al. 2019

Journal of Quantitative Spectroscopy and Radiative Transfer

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Following our recent study devoted to measurements of intensities of rovibrational lines in the ν 6 band of methyl iodide (12 CH 3 I) centered at 892.918 cm −1 , room temperature infrared spectra of methyl iodide diluted in nitrogen at fourteen total pressures between 20 and 300 hPa have been recorded using the Fourier transform spectrometer Bruker IF125HR located at the LISA facility in Créteil. Three hundred and forty six N 2-broadening coefficients of methyl iodide rovibrational lines have been measured in the 824-951 cm −1 spectral range using mono-spectrum non-linear least squares fitting of Voigt profiles. Pressure-induced line shifts were not needed to fit the spectra to the noise level and line mixing effects could be neglected. Six hundred and eight self-broadening coefficients have also been measured in the same spectral range using the pure methyl iodide spectra recorded in our previous work. The measured self-broadening coefficients range from 0.1460 to 0.3786 cm − 1 atm −1 and the N 2-broadening coefficients range from 0.0723 to 0.1481 cm −1 atm − 1 at 295 K. The average accuracy on the measured self-and N 2-broadening coefficients was estimated to 3%. Comparisons with measurements reported in the literature for the ν 5 band of CH 3 I shows a satisfactory agreement with average differences of 7% and 4% for the self-and N 2-broadening coefficients, respectively. The J and K rotational dependences of these coefficients have been observed and the latter modeled using an empirical polynomial expansion. On average, the empirical expression reproduces the measured self-and N 2-broadening coefficients to within 3% and 4%, respectively. The data obtained in the present work represent a significant contribution to the determination of broadening coefficients of CH 3 I and complement the list of line positions and intensities generated in our previous work, thus providing useful spectroscopic information for atmospheric remote sensing and industrial detection of CH 3 I.

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Section: Introductionmentioning

confidence: 99%

Self and N2 collisional broadening of rovibrational lines in the ν6 band of methyl iodide (12CH3I) at room temperature: The J and K dependence

Attafi

Hassen

Aroui

et al. 2019

Journal of Quantitative Spectroscopy and Radiative Transfer

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“…Many of the experimental and theoretical investigations carried out on halogenated ethenes over the past decade were motivated by the role they play as organic trace gas pollutants. − Besides their threats to human health, brominated ethenes (mainly used in industry as intermediates in the production of polymers and pharmaceutical products, as components of fire extinguishers in blends with fluorine-containing compounds, and in the synthesis of copolymers having flame-retardant properties) raise additional concerns in view of their high efficiency at catalyzing the destruction of the Earth’s protective ozone layer. − Among the different techniques available for environmental monitoring, infrared (IR) spectroscopy is one of the most effective; however, its performance relies strongly on the availability of sufficiently accurate spectroscopic data. These are provided by high-resolution studies, which are, however, often complicated by spectral congestion (due to the presence of different isotopomers and several hot bands) and many interacting vibrational levels.…”

Section: Introductionmentioning

confidence: 99%

Accurate Vibrational–Rotational Parameters and Infrared Intensities of 1-Bromo-1-fluoroethene: A Joint Experimental Analysis and Ab Initio Study

et al. 2017

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The medium-resolution gas-phase infrared (IR) spectra of 1-bromo-1-fluoroethene (BrFC═CH, 1,1-CHBrF) were investigated in the range 300-6500 cm, and the vibrational analysis led to the assignment of all fundamentals as well as many overtone and combination bands up to three quanta, thus giving an accurate description of its vibrational structure. Integrated band intensity data were determined with high precision from the measurements of their corresponding absorption cross sections. The vibrational analysis was supported by high-level ab initio investigations. CCSD(T) computations accounting for extrapolation to the complete basis set and core correlation effects were employed to accurately determine the molecular structure and harmonic force field. The latter was then coupled to B2PLYP and MP2 computations in order to account for mechanical and electrical anharmonicities. Second-order perturbative vibrational theory was then applied to the thus obtained hybrid force fields to support the experimental assignment of the IR spectra.

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“…However, with few exceptions, since 1996 these compounds have been phased out by the Montreal protocol (and the Copenhagen amendment), given their capacity to destroy the stratospheric ozone layer and to behave as greenhouse gases. [1][2][3] In fact, they can exercise an additional radiative forcing that tends to warm the climate, contributing to global warming. Several research efforts have been devoted to the study of the radiative forcing and, in general, the spectroscopic behavior of the halogenated organics, with aim of assessing the environmental impacts of these compounds, considering the briefand long-term environmental effects, as well as the contribution to climate changes and global warming (see for example Refs.…”

Section: Introductionmentioning

confidence: 99%

Anharmonic theoretical simulations of infrared spectra of halogenated organic compounds

Carnimeo

Puzzarini²,

Tasinato³

et al. 2013

The Journal of Chemical Physics

105

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The recent implementation of the computation of IR intensities beyond the double-harmonic approximation [Bloino, J.; Barone, V. J. Chem. Phys. 2012, 136, 124108] paved the route to routine calculations of infrared spectra for a wide set of molecular systems. Halogenated organic compounds represent an interesting class of molecules, from both an atmospheric and computational point of view, due to the peculiar chemical features related to the halogen atoms. In this work we simulate the IR spectra of eight halogenated molecules (CH 2 F 2 , CHBrF 2 , CH 2 DBr, CF 3 Br, CH 2 CHF, CF 2 CFCl, cis-CHFCHBr, cis-CHFCHI), using two common hybrid and doublehybrid density functionals in conjunction with both double-and triple-zeta quality basis sets (SNSD and cc-pVTZ) as well as employing the coupled-cluster theory with basis sets of at least triple-zeta quality. Finally, we compare our results with available experimental spectra, with the aim of checking the accuracy and the performances of the computational approaches.

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Overview of High-Resolution Infrared Measurement and Analysis for Atmospheric Monitoring of Halocarbons

Cited by 24 publications

References 89 publications

Self and N2 collisional broadening of rovibrational lines in the ν6 band of methyl iodide (12CH3I) at room temperature: The J and K dependence

Self and N2 collisional broadening of rovibrational lines in the ν6 band of methyl iodide (12CH3I) at room temperature: The J and K dependence

Accurate Vibrational–Rotational Parameters and Infrared Intensities of 1-Bromo-1-fluoroethene: A Joint Experimental Analysis and Ab Initio Study

Anharmonic theoretical simulations of infrared spectra of halogenated organic compounds

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