Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K

IInterstellar molecules containing N atoms, such as ammonia (NH3) and methylamine (CH3NH2), could be potential precursors of amino acids like the simplest one, glycine (NH2CH2COOH). The gas-phase reactivity of these N-bearing species with OH radicals, ubiquitous in the interstellar medium, is not kn...

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Autores: González Pérez de Madrid, Daniel, Ballesteros Ruiz, Bernabé, Canosa, André, Albaladejo Pérez, José, Jiménez, Elena
Tipo de recurso: artículo
Fecha de publicación:2021
País:España
Institución:Universidad de Castilla-La Mancha
Repositorio:RUIdeRA. Repositorio Institucional de la UCLM
OAI Identifier:oai:ruidera.uclm.es:10578/29221
Acceso en línea:http://hdl.handle.net/10578/29221
Access Level:acceso abierto
Palabra clave:ISM
Moléculas prebióticas
Radicales OH
Técnica CRESU
Cinética de reacción
Temperaturas ultrabajas
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spelling Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 KGonzález Pérez de Madrid, DanielBallesteros Ruiz, BernabéCanosa, AndréAlbaladejo Pérez, JoséJiménez, ElenaISMMoléculas prebióticasRadicales OHTécnica CRESUCinética de reacciónTemperaturas ultrabajasIInterstellar molecules containing N atoms, such as ammonia (NH3) and methylamine (CH3NH2), could be potential precursors of amino acids like the simplest one, glycine (NH2CH2COOH). The gas-phase reactivity of these N-bearing species with OH radicals, ubiquitous in the interstellar medium, is not known at temperatures of cold dark molecular clouds. In this work, we present the first kinetic study of these OH-reactions at around 22 K and different gas densities ((3.4-16.7)×1016 cm-3) in helium. The obtained rate coefficients, with ±2 uncertainties, k1(OH+NH3) = (2.7±0.1)×10-11 cm3 s-1 k2(OH+CH3NH2) = (3.9±0.1)×10-10 cm3 s-1 can be included in pure gas-phase or gas-grain astrochemical models to interpret the observed abundances of NH3 and CH3NH2. We observed an increase of k1 and k2 with respect to those previously measured by others at the lowest temperatures for which rate coefficients are presently available: 230 K and 299 K, respectively. This increase is about 380 times for NH3 and 20 times for CH3NH2. Although the OH+NH3 reaction is included in astrochemical kinetic databases, the recommended temperature dependence for k1 is based on kinetic studies at temperatures above 200 K. However, the OH+CH3NH2 reaction is not included in astrochemical networks. The observed increase in k1 at ca. 22 K does not significantly change the abundance of NH3 in a typical cold dark interstellar cloud. However, the inclusion of k2 at ca. 22 K, not considered in astrochemical networks, indicates that the contribution of this destruction route for CH3NH2 is not negligible, accounting for 1/3 of the assumed main depletion route (reaction with HCO+) in this IS environment.Las moléculas interestelares que contienen átomos de N, como el amoníaco (NH3) y la metilamina (CH3NH2), podrían ser precursoras potenciales de aminoácidos como el más simple, la glicina (NH2CH2COOH). La reactividad en fase gaseosa de estas especies portadoras de N con radicales OH, omnipresentes en el medio interestelar, no se conoce a temperaturas de nubes moleculares oscuras y frías. En este trabajo, presentamos el primer estudio cinético de estas reacciones OH a alrededor de 22 K y diferentes densidades de gas ((3.4-16.7) × 1016 cm-3) en helio. Los coeficientes de velocidad obtenidos, con ± 2 incertidumbres, k1 (OH + NH3) = (2.7 ± 0.1) × 10-11 cm3 s-1 k2 (OH + CH3NH2) = (3.9 ± 0.1) × 10-10 cm3 s- 1 se puede incluir en modelos astroquímicos de fase gaseosa pura o de grano de gas para interpretar las abundancias observadas de NH3 y CH3NH2. Observamos un aumento de k1 y k2 con respecto a los medidos previamente por otros a las temperaturas más bajas para las que actualmente se dispone de coeficientes de velocidad: 230 K y 299 K, respectivamente. Este aumento es aproximadamente 380 veces para el NH3 y 20 veces para el CH3NH2. Aunque la reacción OH + NH3 está incluida en las bases de datos cinéticas astroquímicas, la dependencia de temperatura recomendada para k1 se basa en estudios cinéticos a temperaturas superiores a 200 K. Sin embargo, la reacción OH + CH3NH2 no está incluida en las redes astroquímicas. El aumento observado en k1 a ca. 22 K no cambia significativamente la abundancia de NH3 en una típica nube interestelar oscura y fría. Sin embargo, la inclusión de k2 en ca. 22 K,Frontiers202120212021info:eu-repo/semantics/articleapplication/pdfapplication/pdfhttp://hdl.handle.net/10578/29221reponame:RUIdeRA. Repositorio Institucional de la UCLMinstname:Universidad de Castilla-La ManchaEspañolinfo:eu-repo/semantics/openAccessoai:ruidera.uclm.es:10578/292212026-05-27T07:36:41Z
dc.title.none.fl_str_mv Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
title Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
spellingShingle Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
González Pérez de Madrid, Daniel
ISM
Moléculas prebióticas
Radicales OH
Técnica CRESU
Cinética de reacción
Temperaturas ultrabajas
title_short Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
title_full Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
title_fullStr Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
title_full_unstemmed Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
title_sort Gas-phase reactivity of OH radicals with ammonia (NH3) and methylamine (CH3NH2) at around 22 K
dc.creator.none.fl_str_mv González Pérez de Madrid, Daniel
Ballesteros Ruiz, Bernabé
Canosa, André
Albaladejo Pérez, José
Jiménez, Elena
author González Pérez de Madrid, Daniel
author_facet González Pérez de Madrid, Daniel
Ballesteros Ruiz, Bernabé
Canosa, André
Albaladejo Pérez, José
Jiménez, Elena
author_role author
author2 Ballesteros Ruiz, Bernabé
Canosa, André
Albaladejo Pérez, José
Jiménez, Elena
author2_role author
author
author
author
dc.subject.none.fl_str_mv ISM
Moléculas prebióticas
Radicales OH
Técnica CRESU
Cinética de reacción
Temperaturas ultrabajas
topic ISM
Moléculas prebióticas
Radicales OH
Técnica CRESU
Cinética de reacción
Temperaturas ultrabajas
description IInterstellar molecules containing N atoms, such as ammonia (NH3) and methylamine (CH3NH2), could be potential precursors of amino acids like the simplest one, glycine (NH2CH2COOH). The gas-phase reactivity of these N-bearing species with OH radicals, ubiquitous in the interstellar medium, is not known at temperatures of cold dark molecular clouds. In this work, we present the first kinetic study of these OH-reactions at around 22 K and different gas densities ((3.4-16.7)×1016 cm-3) in helium. The obtained rate coefficients, with ±2 uncertainties, k1(OH+NH3) = (2.7±0.1)×10-11 cm3 s-1 k2(OH+CH3NH2) = (3.9±0.1)×10-10 cm3 s-1 can be included in pure gas-phase or gas-grain astrochemical models to interpret the observed abundances of NH3 and CH3NH2. We observed an increase of k1 and k2 with respect to those previously measured by others at the lowest temperatures for which rate coefficients are presently available: 230 K and 299 K, respectively. This increase is about 380 times for NH3 and 20 times for CH3NH2. Although the OH+NH3 reaction is included in astrochemical kinetic databases, the recommended temperature dependence for k1 is based on kinetic studies at temperatures above 200 K. However, the OH+CH3NH2 reaction is not included in astrochemical networks. The observed increase in k1 at ca. 22 K does not significantly change the abundance of NH3 in a typical cold dark interstellar cloud. However, the inclusion of k2 at ca. 22 K, not considered in astrochemical networks, indicates that the contribution of this destruction route for CH3NH2 is not negligible, accounting for 1/3 of the assumed main depletion route (reaction with HCO+) in this IS environment.
publishDate 2021
dc.date.none.fl_str_mv 2021
2021
2021
dc.type.none.fl_str_mv info:eu-repo/semantics/article
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10578/29221
url http://hdl.handle.net/10578/29221
dc.language.none.fl_str_mv Español
language_invalid_str_mv Español
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.format.none.fl_str_mv application/pdf
application/pdf
dc.publisher.none.fl_str_mv Frontiers
publisher.none.fl_str_mv Frontiers
dc.source.none.fl_str_mv reponame:RUIdeRA. Repositorio Institucional de la UCLM
instname:Universidad de Castilla-La Mancha
instname_str Universidad de Castilla-La Mancha
reponame_str RUIdeRA. Repositorio Institucional de la UCLM
collection RUIdeRA. Repositorio Institucional de la UCLM
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,300719

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