Kinetics and Mechanisms of the Oxidation of Oxygenated Organic Compounds in the Gas Phase

Mellouki, A.; Bras, G. Le; Sidebottom, Howard

doi:10.1002/chin.200410287

Cited by 42 publications

(66 citation statements)

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“…DeMore et al, 1997;Atkinson et al, 1999) or in review papers (e.g. Atkinson, 1994;Atkinson and Arey, 2003;Orlando et al, 2003;Mellouki et al, 2003;Calvert et al, 2000). Reasonable estimates can be made by analogy to these known reactions, with the aid of several structure/activity relationships (SARs).…”

Section: Protocol Description For the Development Of The Organic Schemesmentioning

confidence: 99%

Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach

Aumont

Szopa²,

Madronich³

2005

Atmos. Chem. Phys.

290

287

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Abstract. Organic compounds emitted in the atmosphere are oxidized in complex reaction sequences that produce a myriad of intermediates. Although the cumulative importance of these organic intermediates is widely acknowledged, there is still a critical lack of information concerning the detailed composition of the highly functionalized secondary organics in the gas and condensed phases. The evaluation of their impacts on pollution episodes, climate, and the tropospheric oxidizing capacity requires modelling tools that track the identity and reactivity of organic carbon in the various phases down to the ultimate oxidation products, CO and CO 2 . However, a fully detailed representation of the atmospheric transformations of organic compounds involves a very large number of intermediate species, far in excess of the number that can be reasonably written manually. This paper describes (1) the development of a data processing tool to generate the explicit gas-phase oxidation schemes of acyclic hydrocarbons and their oxidation products under tropospheric conditions and (2) the protocol used to select the reaction products and the rate constants. Results are presented using the fully explicit oxidation schemes generated for two test species: n-heptane and isoprene. Comparisons with wellestablished mechanisms were performed to evaluate these generated schemes. Some preliminary results describing the gradual change of organic carbon during the oxidation of a given parent compound are presented.

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Section: Protocol Description For the Development Of The Organic Schemesmentioning

confidence: 99%

Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach

Aumont

Szopa²,

Madronich³

2005

Atmos. Chem. Phys.

290

287

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“…Les étapes de cette oxydation peuvent être décrites par un nombre limité de réactions types, répétées de nombreuses fois jusqu'à l'oxydation complète du composé parent. À quelques exceptions près, ces étapes peuvent être résumées ainsi ( Figure 3 [21,22], ainsi que dans des articles de synthèse [23][24][25][26][27][28][29]. Les données cinétiques et mécanistiques manquantes sont reconstituées soit à partir de relation de structure/réactivité soit sur la base de schémas chimiques paramétrés.…”

Section: éLaboration De Schémas Chimiquesunclassified

“…Il existe aujourd'hui des relations de structure/ réactivité permettant d'estimer les paramètres cinétiques pour les différentes étapes de l'oxydation atmosphérique des COV [3,10,28,30,[33][34][35]. La communauté scientifique est particulièrement active depuis trois décennies pour la production de données expérimentales de cinétique élémentaire.…”

Section: Articlesunclassified

II – Développement de schémas chimiques

Camredon¹,

Aumont²

2007

Pollution Atmosphérique

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RésuméCet article s'insère dans un document à trois volets ayant pour but de décrire l'état de l'art sur la modélisation chimique de l'ozone et des oxydants gazeux. Ce deuxième article porte sur les difficultés associées au développement de schémas chimiques opérationnels à destination des modèles de chimie/transport et présente les différentes approches proposées dans la littérature pour pallier ces difficultés. L'une des étapes clés de la formulation de schémas chimiques est la représen-tation de la chimie organique. Une description explicite de l'oxydation des composés organiques conduit à des mécanismes de grande dimension. Le développement de schémas chimiques se heurte (i) à un problème de documentation des données cinétiques et mécanistiques et (ii) à une intégration inenvisageable des schémas explicites dans les modèles 3D. Le manque de données concernant l'oxydation des composés organiques est généralement pallié par l'utilisation de relations de structure/réactivité ou par le développement de schémas paramétrés. Afin de donner au schéma chimique une taille raisonnable, des réductions sont systématiquement mises en place sur la base de simplifications chimiques et de regroupements intenses. AbstractThis article is the second of a three-part document having for objective to describe the state of the art of chemical modelling of ozone and gaseous oxidants. This second article presents (i) the difficulties encountered during the development of operational chemical schemes for 3D chemistry/transport models and (ii) the various approaches used in the literature to overcome these difficulties. One of the key steps to develop chemical schemes is the representation of organic chemistry. An explicit description of organic compounds oxidation faces two limitations: (i) the number of species and reactions involved exceeds largely that for which the number of experimental kinetic and mechanistic data is available and (ii) an explicit description is too heavy to be efficiently treated in 3D models by current computational tools. Structure/reactivity relationships and parameterized chemical schemes are used to make up for the lack of data. Systematic reductions are developed to reduce chemical schemes from a few millions of species to a few hundreds on the basis of (i) chemical simplifications, usually representative of specific environmental situations and (ii) intense lumpings, with the use of surrogate species and chemical operators.

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“…The importance of the atmospheric chemistry of oxygenated volatile organic compounds (OVOCs) has lately increased due to their role in indoor pollution and secondary organic aerosol (SOA) formation, along with the potential toxicity of some of them and/or their degradation products (Kanakidou et al 2005;Mellouki et al 2003).…”

Section: Introductionmentioning

confidence: 99%

Kinetic study of the gas-phase reactions of hydroxyl radicals and chlorine atoms with cis-3-hexenylformate

Rodrı́guez

Bravo

et al. 2014

Int. J. Environ. Sci. Technol.

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Recently, it has been demonstrated that grass and cut grass are important sources of C6 esters' emissions into the atmosphere. The esters emitted as part of the wound defense mechanisms are responsible for the smell of freshly cut grass and are also highly photochemically reactive. Thus, these grass emissions should be included in models of urban photochemical pollution so that accurate smog predictions can be obtained. In this work, we have carried out a kinetic study of the gas-phase reactions of chlorine atom and hydroxyl radical with cis-3-hexenylformate (HCO 2 CH 2 CH 2 CH=CHC 2 H 5 ) for the first time. This was performed in a Teflon static reactor at room temperature and atmospheric pressure of nitrogen or air using gas chromatography with flame ionization detection. Kinetic rate coefficients obtained for cis-3-hexenylformate were (in units of cm 3 molecule -1 s -1 ) (2.45 ± 0.30) 9 10 -10 and (4.61 ± 0.71) 9 10 -11 for chlorine and hydroxyl radical reactions, respectively. The reaction between the ester and chlorine atoms is very fast, approaching the collisioncontrolled regime; nevertheless, the rate constant for the reaction with hydroxyl radical is lower. In addition, the rate coefficients for the reactions of cis-3-hexenylformate with different atmospheric reactive species were estimated through a Quantitative Structure-Activity Relationship model in which High Occupied Molecular Orbital energy of the formate is used as a theoretical molecular descriptor. Tropospheric lifetimes, based on the homogeneous sinks of the cis-3-hexenylformate, are estimated from the kinetic data obtained in the present work. The relatively short atmospheric lifetimes of the ester indicate that the compound will be oxidized near its anthropogenic origin source.

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Kinetics and Mechanisms of the Oxidation of Oxygenated Organic Compounds in the Gas Phase

Cited by 42 publications

References 1 publication

Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach

Modelling the evolution of organic carbon during its gas-phase tropospheric oxidation: development of an explicit model based on a self generating approach

II – Développement de schémas chimiques

Kinetic study of the gas-phase reactions of hydroxyl radicals and chlorine atoms with cis-3-hexenylformate

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