title: Theoretical study of Δ-3-(+)-carene oxidation.
abstract: In this work, the rate-limiting steps of Δ(3)-carene oxidation by ozone and OH radicals were studied. The thermochemical and kinetic parameters were evaluated using the B3LYP, PBE1PBE and BHandHLYP functionals, coupled cluster methods and the 6-311G(d,p) and 6-311++G(d,p) basis sets. The attack on the double bond may occur in different orientations, leading to different oxidation products. The rate coefficients of each step of the reactions were evaluated using conventional canonical transition-state theory and variational canonical transition-state theory whenever necessary. The theoretical rate coefficient for the ozonolysis mechanism, evaluated at the CCSD(T)/6-31G(d,p)//PBE1PBE/6-311++G(d,p) level, was 2.08 × 10(-17) cm(3) molecule(-1) s(-1). The coefficient for the oxidation initialised by the OH radical, calculated at the BHandHLYP/6-311++G(d,p) level, was 5.06 × 10(-12) cm(3) molecule(-1) s(-1). These values are in reasonable agreement with the experimental results. The importance of these reactions in atmospheric chemistry is discussed.
authors.affiliation: Universidade do Estado do Rio de Janeiro, Faculdade de Tecnologia, Departamento de Química e Ambiental, Rodovia Presidente Dutra Km 298, Resende, RJ, Brazil. leobap@gmail.com.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Baptista
authors.forename: Lilian
authors.initials: L
authors.lastname: Fernandes Francisco
authors.forename: Jacques Fernandes
authors.initials: JF
authors.lastname: Dias
authors.forename: Edilson Clemente
authors.initials: EC
authors.lastname: da Silva
authors.forename: Claudio Vinicius
authors.initials: CV
authors.lastname: Ferreira dos Santos
authors.forename: Felipe Simões
authors.initials: FS
authors.lastname: Gil de Mendonça
authors.forename: Graciela
authors.initials: G
authors.lastname: Arbilla