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Rivela CB, L Cardona A, Blanco MB, Barnes I, Kieninger M, Ventura ON, Teruel MA. Degradation mechanism of 2-fluoropropene by Cl atoms: experimental and theoretical products distribution studies. Phys Chem Chem Phys 2022; 24:5094-5108. [PMID: 35147616 DOI: 10.1039/d1cp03214c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The gas-phase reaction products of 2-fluoropropene (2FP) with Cl atoms have been determined for the first time at 298 K and atmospheric pressure using a 1080 L quartz-glass photoreactor coupled with in situ FTIR spectroscopy to monitor reactants and products. Acetyl fluoride and formyl chloride were observed as the main products with yields of (106 ± 10)% and (100 ± 11)%, respectively. Electronic structure calculations of reactants, intermediates, products and transition states on a detailed mechanism of the reaction were performed by DFT procedures (BMK, M06, M062X/D3), as well as accurate composite methods on both the addition and abstraction reaction channels. From the joint experimental and theoretical studies, we concluded that the reaction occurs primarily via addition to the Cα carbon, with a smaller participation of the addition on the Cβ carbon, which is not produced directly from the separated reactants but from the CH3CFCH2Cl intermediate radical through a submerged transition state. The abstraction channel occurs at larger energies than the addition ones, and also presents a submerged transition state, with a lower barrier. No products arising from this channel are expected. The proposed mechanism explains also why formaldehyde, predicted as a product by former theoretical studies, is not found among the experimental products. The atmospheric implications of the reaction products are assessed.
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Affiliation(s)
- Cynthia B Rivela
- Laboratorio Universitario de Química y Contaminación del Aire (L.U.Q.C.A.), Instituto de Investigaciones en Fisicoquímica de Córdoba (I.N.F.I.Q.C.), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
| | - Alejandro L Cardona
- Laboratorio Universitario de Química y Contaminación del Aire (L.U.Q.C.A.), Instituto de Investigaciones en Fisicoquímica de Córdoba (I.N.F.I.Q.C.), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
| | - María B Blanco
- Laboratorio Universitario de Química y Contaminación del Aire (L.U.Q.C.A.), Instituto de Investigaciones en Fisicoquímica de Córdoba (I.N.F.I.Q.C.), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
| | - Ian Barnes
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal, Wuppertal, Germany
| | - Martina Kieninger
- CCBG-Detema, Facultad de Química, Universidad de la República, 11200 Montevideo, Uruguay.
| | - Oscar N Ventura
- CCBG-Detema, Facultad de Química, Universidad de la República, 11200 Montevideo, Uruguay.
| | - Mariano A Teruel
- Laboratorio Universitario de Química y Contaminación del Aire (L.U.Q.C.A.), Instituto de Investigaciones en Fisicoquímica de Córdoba (I.N.F.I.Q.C.), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba, Ciudad Universitaria, 5000 Córdoba, Argentina.
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The Spectroscopic Characterization of Halogenated Pollutants through the Interplay between Theory and Experiment: Application to R1122. Molecules 2022; 27:molecules27030748. [PMID: 35164013 PMCID: PMC8839295 DOI: 10.3390/molecules27030748] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/13/2022] [Accepted: 01/18/2022] [Indexed: 01/30/2023] Open
Abstract
In the last decade, halogenated ethenes have seen an increasing interest for different applications; in particular, in refrigeration, air-conditioning and heat pumping. At the same time, their adverse effects as atmospheric pollutants require environmental monitoring, especially by remote sensing spectroscopic techniques. For this purpose, an accurate characterization of the spectroscopic fingerprint—in particular, those of relevance for rotational–vibrational spectroscopy—of the target molecules is strongly needed. This work provides an integrated computational–theoretical investigation on R1122 (2-Chloro-1,1-difluoro-ethylene, ClHC=CF2), a compound widely employed as a key intermediate in different chemical processes. State-of-the-art quantum chemical calculations relying on CCSD(T)-based composite schemes and hybrid CCSD(T)/DFT approaches are used to obtain an accurate prediction of the structural, rotational and vibrational spectroscopic properties. In addition, the equilibrium geometry is obtained by exploiting the semi-experimental method. The theoretical predictions are used to guide the analysis of the experimentally recorded gas-phase infrared spectrum, which is assigned in the 400–6500 cm−1 region. Furthermore, absorption cross sections are accurately determined over the same spectral range. Finally, by using the obtained spectroscopic data, a first estimate of the global warming potential of R1122 vibrational spectra is obtained.
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Blázquez S, Espinosa S, Antiñolo M, Albaladejo J, Jiménez E. Kinetics of CF3CH2OCH3 (HFE-263fb2), CHF2CF2CH2OCH3 (HFE-374pcf), and CF3CF2CH2OCH3 (HFE-365mcf3) with OH radicals, IR absorption cross sections, and global warming potentials. Phys Chem Chem Phys 2022; 24:14354-14364. [DOI: 10.1039/d2cp00160h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hydrofluoroethers (HFEs), like CF3CH2OCH3 (HFE-263fb2), CHF2CF2CH2OCH3 (HFE-374pcf), and CF3CF2CH2OCH3 (HFE-365mcf3), have been proposed in the last decades as the third-generation replacements of perfluorocarbons (PFCs) and hydrofluorocarbons (HFCs) because of their...
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Rivela CB, Gibilisco RG, Tovar CM, Barnes I, Wiesen P, Blanco MB, Teruel MA. FTIR product study of the Cl-initiated oxidation products of CFC replacements: ( E/ Z)-1,2,3,3,3-pentafluoropropene and hexafluoroisobutylene. RSC Adv 2021; 11:12739-12747. [PMID: 35423798 PMCID: PMC8696996 DOI: 10.1039/d1ra00283j] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2021] [Accepted: 03/10/2021] [Indexed: 11/21/2022] Open
Abstract
A product study of the reactions of (E/Z)-1,2,3,3,3-pentafluoropropene ((E/Z)-CF3CF[double bond, length as m-dash]CHF) and hexafluoroisobutylene ((CF3)2C[double bond, length as m-dash]CH2) initiated by Cl atoms were developed at 298 ± 2 K and atmospheric pressure. The experiments were carried out in a 1080 L quartz-glass environmental chamber coupled via in situ FTIR spectroscopy to monitor the reactants and products. The main products observed and their yields were as follows: CF3C(O)F (106 ± 9)% with HC(O)F (100 ± 8)% as a co-product for (E/Z)-CF3CF[double bond, length as m-dash]CHF, and CF3C(O)CF3 (94 ± 5)% with HC(O)Cl (90 ± 7)% as a co-product for (CF3)2C[double bond, length as m-dash]CH2. Atmospheric implications of the end-product degradation are assessed in terms of their impact on ecosystems to help environmental policymakers consider HFOs as acceptable replacements.
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Affiliation(s)
- Cynthia B Rivela
- Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba Argentina
| | - Rodrigo G Gibilisco
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - Carmen M Tovar
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - Ian Barnes
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - Peter Wiesen
- Physikalische Chemie/FBC, Bergische Universitaet Wuppertal Wuppertal Germany
| | - María B Blanco
- Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba Argentina
| | - Mariano A Teruel
- Instituto de Investigaciones en Fisicoquímica de Córdoba (INFIQC), CONICET, Dpto. de Fisicoquímica, Facultad de Ciencias Químicas, Universidad Nacional de Córdoba Ciudad Universitaria 5000 Córdoba Argentina
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Ray AW, Weidner P, Bodi A, Sztáray B. The Vagabond Fluorine Atom: Dissociative Photoionization of trans-1,3,3,3-Tetrafluoropropene. J Phys Chem A 2020; 124:3738-3746. [DOI: 10.1021/acs.jpca.0c01804] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Amelia W. Ray
- Department of Chemistry, University of the Pacific, Stockton, California 95211, United States
| | - Peter Weidner
- Department of Chemistry, University of the Pacific, Stockton, California 95211, United States
| | - Andras Bodi
- Laboratory for Synchrotron Radiation and Femtochemistry, Paul Scherrer Institute, CH-5232 Villigen, PSI, Switzerland
| | - Bálint Sztáray
- Department of Chemistry, University of the Pacific, Stockton, California 95211, United States
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Xu C, Wang C, Li B, Hu L, Gu FL. Theoretical study on the reaction mechanism of OH radical with Z(E)-CF3CHCHF. Phys Chem Chem Phys 2019; 21:1367-1374. [DOI: 10.1039/c8cp06647g] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The comprehensive transformation mechanism and kinetics of Z(E)-CF3CHCHF initiated by OH radicals were investigated by performing quantum chemical calculations.
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Affiliation(s)
- Chao Xu
- Key Laboratory of Theoretical Chemistry of Environment
- Ministry of Education
- School of Chemistry & Environment of South China
- Normal University
- Guangzhou 510006
| | - Chaoyang Wang
- Key Laboratory of Theoretical Chemistry of Environment
- Ministry of Education
- School of Chemistry & Environment of South China
- Normal University
- Guangzhou 510006
| | - Bo Li
- Key Laboratory of Theoretical Chemistry of Environment
- Ministry of Education
- School of Chemistry & Environment of South China
- Normal University
- Guangzhou 510006
| | - Linping Hu
- Key Laboratory of Theoretical Chemistry of Environment
- Ministry of Education
- School of Chemistry & Environment of South China
- Normal University
- Guangzhou 510006
| | - Feng Long Gu
- Key Laboratory of Theoretical Chemistry of Environment
- Ministry of Education
- School of Chemistry & Environment of South China
- Normal University
- Guangzhou 510006
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