Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and...

Autores
Blanco, Maria Belen; Barnes, Ian; Wiesen, Peter; Teruel, Mariano Andres
Año de publicación
2016
Idioma
inglés
Tipo de recurso
artículo
Estado
versión publicada
Descripción
Rate coefficients as a function of temperature have been measured for the first time for the gas-phase reactions of chlorine atoms with methyl chlorodifluoracetate (k1) and ethyl chlorodifluoroacetate (k2) using the relative rate technique. The experiments were carried out in a 1080 L photoreactor over the temperature range 287-313 K at a total pressure of 1000 ± 10 mbar of synthetic air using in situ FTIR spectroscopy to monitor reactants and products. The following Arrhenius expressions were obtained: k(MCDFA+Cl) = (9.6 ± 5.1) × 10-12exp[-(1363 ± 79)/T] and k(ECDFA+Cl) = (64.4 ± 29.7) × 10-12exp[-(1110 ± 68)/T]. The kinetic results are compared with previous experimental and theoretical studies. In addition, a product study of the reactions of Cl with methyl chlorodifluoracetate and ethyl chlorodifluoroacetate is reported. The results indicate that in the absence of NOx the main fate of the alkoxy radicals formed after H-atom abstraction by Cl from the -CH3 group in methyl chlorodifluoroacetate is reaction of the radical with O2 to form the mixed anhydride CF2ClC(O)OC(O)H. In the case of ethyl chlorodifluoroacetate the main fate of the alkoxy formed via H-atom abstraction by Cl from the -CH2- entity in the ethyl group is α-ester rearrangement to produce chlorodifluoroacetic acid and the corresponding radical. The yields of chlorofluoracetic acid (CF2ClC(O)OH) obtained were as follows: (34 ± 5)% and (86 ± 8)% for the reactions of Cl with CF2ClC(O)OCH3 and CF2ClC(O)OCH2CH3, respectively. The measured yields are rationalized in terms of mechanisms consisting of competitive reaction channels for the formed products in the oxidation, i.e. reaction with O2, α-ester rearrangement and a decomposition pathway. Atmospheric implications are discussed according to the rate coefficients obtained as a function of temperature and altitude, and regarding the formation of chlorofluorocarboxylic acid.
Fil: Blanco, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina
Fil: Barnes, Ian. Bergische Universität Wuppertal; Alemania
Fil: Wiesen, Peter. Bergische Universität Wuppertal; Alemania
Fil: Teruel, Mariano Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina
Materia
Cfcs Replacements
Clorofluoroacetates
Kinetics
Mechanisms
Nivel de accesibilidad
acceso abierto
Condiciones de uso
https://creativecommons.org/licenses/by/2.5/ar/
Repositorio
CONICET Digital (CONICET)
Institución
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identificador
oai:ri.conicet.gov.ar:11336/54900
Acceder
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oai_identifier_str oai:ri.conicet.gov.ar:11336/54900
network_acronym_str CONICETDig
repository_id_str 3498
network_name_str CONICET Digital (CONICET)
spelling Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formationBlanco, Maria BelenBarnes, IanWiesen, PeterTeruel, Mariano AndresCfcs ReplacementsClorofluoroacetatesKineticsMechanismshttps://purl.org/becyt/ford/1.4https://purl.org/becyt/ford/1Rate coefficients as a function of temperature have been measured for the first time for the gas-phase reactions of chlorine atoms with methyl chlorodifluoracetate (k1) and ethyl chlorodifluoroacetate (k2) using the relative rate technique. The experiments were carried out in a 1080 L photoreactor over the temperature range 287-313 K at a total pressure of 1000 ± 10 mbar of synthetic air using in situ FTIR spectroscopy to monitor reactants and products. The following Arrhenius expressions were obtained: k(MCDFA+Cl) = (9.6 ± 5.1) × 10-12exp[-(1363 ± 79)/T] and k(ECDFA+Cl) = (64.4 ± 29.7) × 10-12exp[-(1110 ± 68)/T]. The kinetic results are compared with previous experimental and theoretical studies. In addition, a product study of the reactions of Cl with methyl chlorodifluoracetate and ethyl chlorodifluoroacetate is reported. The results indicate that in the absence of NOx the main fate of the alkoxy radicals formed after H-atom abstraction by Cl from the -CH3 group in methyl chlorodifluoroacetate is reaction of the radical with O2 to form the mixed anhydride CF2ClC(O)OC(O)H. In the case of ethyl chlorodifluoroacetate the main fate of the alkoxy formed via H-atom abstraction by Cl from the -CH2- entity in the ethyl group is α-ester rearrangement to produce chlorodifluoroacetic acid and the corresponding radical. The yields of chlorofluoracetic acid (CF2ClC(O)OH) obtained were as follows: (34 ± 5)% and (86 ± 8)% for the reactions of Cl with CF2ClC(O)OCH3 and CF2ClC(O)OCH2CH3, respectively. The measured yields are rationalized in terms of mechanisms consisting of competitive reaction channels for the formed products in the oxidation, i.e. reaction with O2, α-ester rearrangement and a decomposition pathway. Atmospheric implications are discussed according to the rate coefficients obtained as a function of temperature and altitude, and regarding the formation of chlorofluorocarboxylic acid.Fil: Blanco, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Barnes, Ian. Bergische Universität Wuppertal; AlemaniaFil: Wiesen, Peter. Bergische Universität Wuppertal; AlemaniaFil: Teruel, Mariano Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaRoyal Society of Chemistry2016-05-20info:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionhttp://purl.org/coar/resource_type/c_6501info:ar-repo/semantics/articuloapplication/pdfapplication/pdfhttp://hdl.handle.net/11336/54900Blanco, Maria Belen; Barnes, Ian; Wiesen, Peter; Teruel, Mariano Andres; Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation; Royal Society of Chemistry; RSC Advances; 6; 57; 20-5-2016; 51834-518442046-2069CONICET DigitalCONICETenginfo:eu-repo/semantics/altIdentifier/url/http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra03454cinfo:eu-repo/semantics/altIdentifier/doi/10.1039/C6RA03454Cinfo:eu-repo/semantics/openAccesshttps://creativecommons.org/licenses/by/2.5/ar/reponame:CONICET Digital (CONICET)instname:Consejo Nacional de Investigaciones Científicas y Técnicas2025-10-22T11:52:40Zoai:ri.conicet.gov.ar:11336/54900instacron:CONICETInstitucionalhttp://ri.conicet.gov.ar/Organismo científico-tecnológicoNo correspondehttp://ri.conicet.gov.ar/oai/requestdasensio@conicet.gov.ar; lcarlino@conicet.gov.arArgentinaNo correspondeNo correspondeNo correspondeopendoar:34982025-10-22 11:52:41.132CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicasfalse
dc.title.none.fl_str_mv Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
title Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
spellingShingle Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
Blanco, Maria Belen
Cfcs Replacements
Clorofluoroacetates
Kinetics
Mechanisms
title_short Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
title_full Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
title_fullStr Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
title_full_unstemmed Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
title_sort Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation
dc.creator.none.fl_str_mv Blanco, Maria Belen
Barnes, Ian
Wiesen, Peter
Teruel, Mariano Andres
author Blanco, Maria Belen
author_facet Blanco, Maria Belen
Barnes, Ian
Wiesen, Peter
Teruel, Mariano Andres
author_role author
author2 Barnes, Ian
Wiesen, Peter
Teruel, Mariano Andres
author2_role author
author
author
dc.subject.none.fl_str_mv Cfcs Replacements
Clorofluoroacetates
Kinetics
Mechanisms
topic Cfcs Replacements
Clorofluoroacetates
Kinetics
Mechanisms
purl_subject.fl_str_mv https://purl.org/becyt/ford/1.4
https://purl.org/becyt/ford/1
dc.description.none.fl_txt_mv Rate coefficients as a function of temperature have been measured for the first time for the gas-phase reactions of chlorine atoms with methyl chlorodifluoracetate (k1) and ethyl chlorodifluoroacetate (k2) using the relative rate technique. The experiments were carried out in a 1080 L photoreactor over the temperature range 287-313 K at a total pressure of 1000 ± 10 mbar of synthetic air using in situ FTIR spectroscopy to monitor reactants and products. The following Arrhenius expressions were obtained: k(MCDFA+Cl) = (9.6 ± 5.1) × 10-12exp[-(1363 ± 79)/T] and k(ECDFA+Cl) = (64.4 ± 29.7) × 10-12exp[-(1110 ± 68)/T]. The kinetic results are compared with previous experimental and theoretical studies. In addition, a product study of the reactions of Cl with methyl chlorodifluoracetate and ethyl chlorodifluoroacetate is reported. The results indicate that in the absence of NOx the main fate of the alkoxy radicals formed after H-atom abstraction by Cl from the -CH3 group in methyl chlorodifluoroacetate is reaction of the radical with O2 to form the mixed anhydride CF2ClC(O)OC(O)H. In the case of ethyl chlorodifluoroacetate the main fate of the alkoxy formed via H-atom abstraction by Cl from the -CH2- entity in the ethyl group is α-ester rearrangement to produce chlorodifluoroacetic acid and the corresponding radical. The yields of chlorofluoracetic acid (CF2ClC(O)OH) obtained were as follows: (34 ± 5)% and (86 ± 8)% for the reactions of Cl with CF2ClC(O)OCH3 and CF2ClC(O)OCH2CH3, respectively. The measured yields are rationalized in terms of mechanisms consisting of competitive reaction channels for the formed products in the oxidation, i.e. reaction with O2, α-ester rearrangement and a decomposition pathway. Atmospheric implications are discussed according to the rate coefficients obtained as a function of temperature and altitude, and regarding the formation of chlorofluorocarboxylic acid.
Fil: Blanco, Maria Belen. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina
Fil: Barnes, Ian. Bergische Universität Wuppertal; Alemania
Fil: Wiesen, Peter. Bergische Universität Wuppertal; Alemania
Fil: Teruel, Mariano Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; Argentina
description Rate coefficients as a function of temperature have been measured for the first time for the gas-phase reactions of chlorine atoms with methyl chlorodifluoracetate (k1) and ethyl chlorodifluoroacetate (k2) using the relative rate technique. The experiments were carried out in a 1080 L photoreactor over the temperature range 287-313 K at a total pressure of 1000 ± 10 mbar of synthetic air using in situ FTIR spectroscopy to monitor reactants and products. The following Arrhenius expressions were obtained: k(MCDFA+Cl) = (9.6 ± 5.1) × 10-12exp[-(1363 ± 79)/T] and k(ECDFA+Cl) = (64.4 ± 29.7) × 10-12exp[-(1110 ± 68)/T]. The kinetic results are compared with previous experimental and theoretical studies. In addition, a product study of the reactions of Cl with methyl chlorodifluoracetate and ethyl chlorodifluoroacetate is reported. The results indicate that in the absence of NOx the main fate of the alkoxy radicals formed after H-atom abstraction by Cl from the -CH3 group in methyl chlorodifluoroacetate is reaction of the radical with O2 to form the mixed anhydride CF2ClC(O)OC(O)H. In the case of ethyl chlorodifluoroacetate the main fate of the alkoxy formed via H-atom abstraction by Cl from the -CH2- entity in the ethyl group is α-ester rearrangement to produce chlorodifluoroacetic acid and the corresponding radical. The yields of chlorofluoracetic acid (CF2ClC(O)OH) obtained were as follows: (34 ± 5)% and (86 ± 8)% for the reactions of Cl with CF2ClC(O)OCH3 and CF2ClC(O)OCH2CH3, respectively. The measured yields are rationalized in terms of mechanisms consisting of competitive reaction channels for the formed products in the oxidation, i.e. reaction with O2, α-ester rearrangement and a decomposition pathway. Atmospheric implications are discussed according to the rate coefficients obtained as a function of temperature and altitude, and regarding the formation of chlorofluorocarboxylic acid.
publishDate 2016
dc.date.none.fl_str_mv 2016-05-20
dc.type.none.fl_str_mv info:eu-repo/semantics/article
info:eu-repo/semantics/publishedVersion
http://purl.org/coar/resource_type/c_6501
info:ar-repo/semantics/articulo
format article
status_str publishedVersion
dc.identifier.none.fl_str_mv http://hdl.handle.net/11336/54900
Blanco, Maria Belen; Barnes, Ian; Wiesen, Peter; Teruel, Mariano Andres; Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation; Royal Society of Chemistry; RSC Advances; 6; 57; 20-5-2016; 51834-51844
2046-2069
CONICET Digital
CONICET
url http://hdl.handle.net/11336/54900
identifier_str_mv Blanco, Maria Belen; Barnes, Ian; Wiesen, Peter; Teruel, Mariano Andres; Atmospheric sink of methyl chlorodifluoroacetate and ethyl chlorodifluoroacetate: Temperature dependent rate coefficients, product distribution of their reactions with Cl atoms and CF2ClC(O)OH formation; Royal Society of Chemistry; RSC Advances; 6; 57; 20-5-2016; 51834-51844
2046-2069
CONICET Digital
CONICET
dc.language.none.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv info:eu-repo/semantics/altIdentifier/url/http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra03454c
info:eu-repo/semantics/altIdentifier/doi/10.1039/C6RA03454C
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
https://creativecommons.org/licenses/by/2.5/ar/
eu_rights_str_mv openAccess
rights_invalid_str_mv https://creativecommons.org/licenses/by/2.5/ar/
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Royal Society of Chemistry
publisher.none.fl_str_mv Royal Society of Chemistry
dc.source.none.fl_str_mv reponame:CONICET Digital (CONICET)
instname:Consejo Nacional de Investigaciones Científicas y Técnicas
reponame_str CONICET Digital (CONICET)
collection CONICET Digital (CONICET)
instname_str Consejo Nacional de Investigaciones Científicas y Técnicas
repository.name.fl_str_mv CONICET Digital (CONICET) - Consejo Nacional de Investigaciones Científicas y Técnicas
repository.mail.fl_str_mv dasensio@conicet.gov.ar; lcarlino@conicet.gov.ar
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score 12.982451

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