Jet-cooled diode laser spectrum and FTIR integrated band intensities of CF3Br: rovibrational analysis of 2ν5and ν2 + ν3bands near 9 μm and cross-section measurements in the 450–2500 cm−1region

Charmet, Andrea Pietropolli; Tasinato, Nicola; Stoppa, Paolo; Baldacci, A.; Giorgianni, S.

doi:10.1080/00268970802026709

Cited by 15 publications

(9 citation statements)

References 38 publications

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“…To compare the ab initio values with the experimental data for each absorption feature, the experimental integrated cross section G int (cm molecule −1 ) was retrieved by integrating the absorbance cross section σ(νtrue~) over an integration limit corresponding to wavenumbers of negligible absorption. By following the procedure outlined elsewhere, 66 the experimental uncertainty was estimated to be generally better than 5% and 10% for the strongest and weakest signals, respectively. Table IX presents the obtained integrated absorption cross sections and the corresponding integration limits; for comparison purposes the HYB-1 and HYB-2 values are also reported.…”

Section: Resultsmentioning

confidence: 99%

An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane

Charmet

Stoppa

Tasinato

et al. 2013

The Journal of Chemical Physics

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The vibrational analysis of the gas-phase infrared spectra of chlorofluoromethane (CH 2 ClF, HCFC-31) was carried out in the range 200 -6200 cm −1 . The assignment of the absorption features in terms of fundamental, overtone, combination and hot bands was performed on the medium-resolution (up to 0.2 cm −1 ) Fourier transform infrared (FTIR) spectra. From the absorption cross section spectra accurate values of the integrated band intensities were derived and the Global Warming Potential (GWP) of this compound was estimated, thus obtaining values of 323, 83 and 42 on a 20-, 100-and 500-year horizon, respectively. The set of spectroscopic parameters here presented provides the basic data to model the atmospheric behavior of this greenhouse gas. In addition, the obtained vibrational properties were used to benchmark the predictions of state-of-the-art quantum-chemical computational strategies. Extrapolated complete basis set (CBS) limit values for the equilibrium geometry and harmonic force field were obtained at the coupled-cluster singles and doubles level of theory augmented by a perturbative treatment of triple excitations, CCSD(T), in conjunction with a hierarchical series of correlation-consistent basis sets (cc-pVnZ, with n = T, Q and 5), taking also into account the core-valence (CV) correlation effects and the corrections due to diffuse (aug) functions. To obtain the cubic and quartic semi-diagonal force constants, calculations employing second-order Møller-Plesset perturbation (MP2) theory, the double-hybrid DFT functional (B2PLYP) as well as CCSD(T) were performed. For all anharmonic force fields the performances of two different perturbative a Author to whom the correspondence should be addressed. jacpnike@unive.it. Europe PMC Funders GroupAuthor Manuscript J Chem Phys. Author manuscript; available in PMC 2015 October 20. Europe PMC Funders Author ManuscriptsEurope PMC Funders Author Manuscripts approaches in computing the vibrational energy levels (i.e., the generalized second order vibrational treatment, GVPT2, and the recently proposed hybrid degeneracy corrected model, HDCPT2) were evaluated and the obtained results allowed us to validate the spectroscopic predictions yielded by the HDCPT2 approach. The predictions of the deperturbed second-order perturbation approach, DVPT2, applied to the computation of infrared intensities beyond the double-harmonic approximation were compared to the accurate experimental values here determined. Anharmonic DFT and MP2 corrections to CCSD(T) intensities led to a very good agreement with the absorption cross section measurements over the whole spectral range here analysed.

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Section: Resultsmentioning

confidence: 99%

An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane

Charmet

Stoppa

Tasinato

et al. 2013

The Journal of Chemical Physics

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“…Cross section measurements (obtained at a resolution of 0.5 cm –1 ) were carried out by keeping the cell temperature constant at 298(±0.5) K and by adding up to 256 interferograms to maximize the SNR. Distortions due to finite-resolution effects , were minimized, based on the methodologies established in precedent works, , by mixing the sample with N 2 (SIAD, purity >99%) up to a total pressure of 101 kPa. Adsorption of the sample on the cell walls, checked by monitoring pressure and inspecting the absorption spectra, was found to be negligible over a longer period of time than that needed to obtain a spectrum.…”

Section: Methodsmentioning

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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“…[185] Estimates of the RE of Halon-1301 in the literatures range from 0.27 to 0.33 W m À2 ppb À1 (mean: 0.30 W m À2 ppb À1 ) [Charmet et al, 2008;Drage et al, 2006;Jain et al, 2000;Orkin et al, 2003;Ramanathan et al, 1985;Sihra et al, 2001]. AR4 used a RE of 0.32 W m À2 ppb À1 taken from Ramanathan et al [1985].…”

Section: Halon-1201 (Chbrf 2 )mentioning

confidence: 99%

“…AR4 used a RE of 0.32 W m À2 ppb À1 taken from Ramanathan et al [1985]. We have used absorption cross sections from three sources [Charmet et al, 2008;Orkin et al, 2003;Sihra et al, 2001] and calculated a mean RE value of 0.30 W m À2 ppb À1 (range: 0.29-0.31 W m À2 ppb À1 ), about 6% lower than AR4. 4.1.5.7.…”

Section: Halon-1201 (Chbrf 2 )mentioning

confidence: 99%

Global warming potentials and radiative efficiencies of halocarbons and related compounds: A comprehensive review

Hodnebrog

Etminan

Fuglestvedt

et al. 2013

Reviews of Geophysics

431

441

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[1] In the mid-1970s, it was recognized that chlorofluorocarbons (CFCs) were strong greenhouse gases that could have substantial impacts on radiative forcing of climate change, as well as being substances that deplete stratospheric ozone. Around a decade later, this group of radiatively active compounds was expanded to include a large number of replacements for ozone-depleting substances such as chlorocarbons, hydrochlorocarbons, hydrochlorofluorocarbons (HCFCs), hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), bromofluorocarbons, and bromochlorofluorocarbons. This paper systematically reviews the published literature concerning the radiative efficiencies (REs) of CFCs, bromofluorocarbons and bromochlorofluorocarbons (halons), HCFCs, HFCs, PFCs, sulfur hexafluoride, nitrogen trifluoride, and related halogen containing compounds. In addition, we provide a comprehensive and self-consistent set of new calculations of REs and global warming potentials (GWPs) for these compounds, mostly employing atmospheric lifetimes taken from the available literature. We also present global temperature change potentials for selected gases. Infrared absorption spectra used in the RE calculations were taken from databases and individual studies and from experimental and ab initio computational studies. Evaluations of REs and GWPs are presented for more than 200 compounds. Our calculations yield REs significantly (> 5%) different from those in the Intergovernmental Panel on Climate Change Fourth Assessment Report (AR4) for 49 compounds. We present new RE values for more than 100 gases which were not included in AR4. A widely used simple method to calculate REs and GWPs from absorption spectra and atmospheric lifetimes is assessed and updated. This is the most comprehensive review of the radiative efficiencies and global warming potentials of halogenated compounds performed to date.

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Jet-cooled diode laser spectrum and FTIR integrated band intensities of CF₃Br: rovibrational analysis of 2ν₅and ν₂ + ν₃bands near 9 μm and cross-section measurements in the 450–2500 cm⁻¹region

Cited by 15 publications

References 38 publications

An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane

An integrated experimental and quantum-chemical investigation on the vibrational spectra of chlorofluoromethane

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

Global warming potentials and radiative efficiencies of halocarbons and related compounds: A comprehensive review

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