title: Atmospheric fate of hydrofluoroolefins, CxF2x+1CHCH2(x = 1,2,3,4 and 6): Kinetics with Cl atoms and products.
abstract: Rate coefficients for the gas-phase reactions of CxF2x+1CHCH2(x = 1, 2, 3, 4 and 6) with Cl atoms were determined at (298 ± 2) K and (710 ± 5) Torr of air using a relative rate technique. Two experimental setups with simulation chambers were employed with Fourier Transform Infrared (FTIR) spectroscopy and Gas Chromatography coupled to Mass Spectrometry (GC-MS) as detection techniques. The Cl-rate coefficients obtained were (in 10-10cm3molecule-1s-1): (0.85 ± 0.11) for CF3CHCH2, (1.11 ± 0.08) for C2F5CHCH2, (1.12 ± 0.18) for C3F7CHCH2, (0.97 ± 0.09) for C4F9CHCH2, and (0.99 ± 0.08) for C6F13CHCH2. Additionally, the gas-phase products were identified and quantified, when possible, by FTIR spectroscopy or GC-MS. The main reaction product was reported to be CxF2x+1C(O)CH2Cl. The fluorinated species, CxF2x+1CHO and CxF2x+1C(O)CH2Cl, were identified. CF3C(O)CH2Cl and CF3CHO were found to be formed with molar yield of (69 ± 5)% and (9 ± 1)%, respectively. The global lifetime of the investigated CxF2x+1CHCH2due to their Cl-reaction is more than 100 days so this route does not compete with the removal by OH radicals. This lifetime is long enough for CxF2x+1CHCH2to be transported to remote areas where they can be degraded. However, at a local scale, in marine regions at dawn the removal of CxF2x+1CHCH2is expected to occur in ca. 1 day. The atmospheric degradation of these hydrofluoroolefins by Cl atoms is not expected to be a source of bioaccumulative perfluorinated carboxylic acids, CxF2x+1C(O)OH. Additionally, the UV absorption cross sections of CF3C(O)CH2Cl were determined together with the rate coefficient of the OH reaction by an absolute kinetic method at room temperature.
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela 1B, 13071 Ciudad Real, Spain; Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain. Electronic address: Bernabe.Ballesteros@uclm.es.
authors.forename: Bernabé
authors.initials: B
authors.lastname: Ballesteros
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela 1B, 13071 Ciudad Real, Spain; Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain.
authors.forename: Elena
authors.initials: E
authors.lastname: Jiménez
authors.affiliation: Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain.
authors.forename: Alberto
authors.initials: A
authors.lastname: Moreno
authors.affiliation: Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain.
authors.forename: Amparo
authors.initials: A
authors.lastname: Soto
authors.affiliation: Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Antiñolo
authors.affiliation: Departamento de Química Física, Facultad de Ciencias y Tecnologías Químicas, Universidad de Castilla-La Mancha, Avenida Camilo José Cela 1B, 13071 Ciudad Real, Spain; Instituto de Investigación en Combustión y Contaminación Atmosférica, Universidad de Castilla-La Mancha, Camino de Moledores s/n, 13071 Ciudad Real, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Albaladejo
mesh_terms: D000393:Air Pollutants / Q000032:analysis / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D002264:Carboxylic Acids / Q000032:analysis / Q000737:chemistry; D002713:Chlorine / Q000737:chemistry*; D005466:Fluorocarbons / Q000032:analysis / Q000737:chemistry; D008401:Gas Chromatography-Mass Spectrometry; D006845:Hydrocarbons, Fluorinated / Q000032:analysis / Q000737:chemistry*; D017665:Hydroxyl Radical / Q000737:chemistry; D007700:Kinetics; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D000393:Air Pollutants; D002264:Carboxylic Acids; D005466:Fluorocarbons; D006845:Hydrocarbons, Fluorinated; C068177:3,3,4,4,5,5,6,6,6-nonafluoro-1-hexene; D017665:Hydroxyl Radical; D002713:Chlorine; C519087:3,3,3-trifluoro-1-propene
keywords: Cl atoms; Hydrofluoroolefins; Kinetics; Lifetime; Mechanism; Troposphere