title: Kinetic, mechanistic and temperature dependence study of Cl reactions with CH3OC(O)H and CH3CH2OC(O)H. Atmospheric implications.
abstract: Reactions of Cl atoms with CH(3)OC(O)H (1) and CH(3)CH(2)OC(O)H (2) have been studied using the Discharge Flow-Mass Spectrometric (DF-MS) method. The study has been carried out at 1 Torr total pressure under pseudo-first-order conditions in the temperature range 253 K to 333 K to approach the tropospheric temperature profile. The measured room temperature rate coefficients are k(1)=(1.01+/-0.15) x 10(-12) cm(3) molecule(-1) s(-1) and k(2)=(8.78+/-1.22) x 10(-12) cm(3) molecule(-1) s(-1) (errors are 2sigma) and the fitted Arrhenius expressions, k(1)=(1.7+/-1.4) x 10(-11) exp -(810+/-250)/T cm(3) molecule(-1) s(-1) and k(2)=(5.5+/-4.8) x 10(-11) exp -(556+/-268)/T cm(3) molecule(-1) s(-1) (errors are 2sigma). The reactions proceed through the abstraction of an H atom to form HCl and the corresponding radical. At 298 K and 1 Torr, yields on HCl of 0.95+/-0.09 (error is 2sigma) for reaction (1) and 0.96+/-0.11 (error is 2sigma) for reaction (2) have been measured. The tropospheric lifetimes are calculated and discussed.
authors.affiliation: Facultad de Químicas, Universidad Castilla-La Mancha, Avenida Camilo José Cela 10, 13071 Ciudad Real, Spain.
authors.forename: Iván
authors.initials: I
authors.lastname: Bravo
authors.forename: Alfonso
authors.initials: A
authors.lastname: Aranda
authors.forename: Yolanda
authors.initials: Y
authors.lastname: Díaz-de-Mera
authors.forename: Elena
authors.initials: E
authors.lastname: Moreno
authors.forename: Maria E
authors.initials: ME
authors.lastname: Tucceri
authors.forename: Diana
authors.initials: D
authors.lastname: Rodríguez
mesh_terms: D019342:Acetic Acid / Q000737:chemistry*; D001272:Atmosphere / Q000737:chemistry*; D002713:Chlorine / Q000737:chemistry*; D007700:Kinetics; D011422:Propionates / Q000737:chemistry*; D013696:Temperature
chemical_list: D011422:Propionates; D002713:Chlorine; C029658:propionic acid; D019342:Acetic Acid