TY - JOUR
T1 - Atmospheric Chemistry of Isopropyl Formate and tert-Butyl Formate
AU - Pimentel, Andre Silva
AU - Tyndall, Geoffrey S.
AU - Orlando, John J.
AU - Hurley, Michale D.
AU - Wallington, Timothy J.
AU - Andersen, Mads Peter Sulbæk
AU - Marshall, Paul
AU - Dibble, Theodore S.
PY - 2010/8
Y1 - 2010/8
N2 - Formates are produced in the atmosphere as a result of the oxidation of a number of species, notably dialkyl ethers and vinyl ethers. This work describes experiments to define the oxidation mechanisms of isopropyl formate, HC(O)OCH(CH3)2, and tert-butyl formate, HC(O)OC(CH 3)3. Product distributions are reported from both Cl- and OH-initiated oxidation, and reaction mechanisms are proposed to account for the observed products. The proposed mechanisms include examples of the α-ester rearrangement reaction, novel isomerization pathways, and chemically activated intermediates. The atmospheric oxidation of isopropyl formate by OH radicals gives the following products (molar yields): acetic formic anhydride (43%), acetone (43%), and HCOOH (15-20%). The OH radical initiated oxidation of tert-butyl formate gives acetone, formaldehyde, and CO2 as major products. IR absorption cross sections were derived for two acylperoxy nitrates derived from the title compounds. Rate coefficients are derived for the kinetics of the reactions of isopropyl formate with OH (2.4 ± 0.6) × 10-12, and with Cl (1.75 ± 0.35) × 10-11, and for tert-butyl formate with Cl (1.45 ± 0.30) × 10-11 cm3 molecule-1 s-1. Simple group additivity rules fail to explain the observed distribution of sites of H-atom abstraction for simple formates.
AB - Formates are produced in the atmosphere as a result of the oxidation of a number of species, notably dialkyl ethers and vinyl ethers. This work describes experiments to define the oxidation mechanisms of isopropyl formate, HC(O)OCH(CH3)2, and tert-butyl formate, HC(O)OC(CH 3)3. Product distributions are reported from both Cl- and OH-initiated oxidation, and reaction mechanisms are proposed to account for the observed products. The proposed mechanisms include examples of the α-ester rearrangement reaction, novel isomerization pathways, and chemically activated intermediates. The atmospheric oxidation of isopropyl formate by OH radicals gives the following products (molar yields): acetic formic anhydride (43%), acetone (43%), and HCOOH (15-20%). The OH radical initiated oxidation of tert-butyl formate gives acetone, formaldehyde, and CO2 as major products. IR absorption cross sections were derived for two acylperoxy nitrates derived from the title compounds. Rate coefficients are derived for the kinetics of the reactions of isopropyl formate with OH (2.4 ± 0.6) × 10-12, and with Cl (1.75 ± 0.35) × 10-11, and for tert-butyl formate with Cl (1.45 ± 0.30) × 10-11 cm3 molecule-1 s-1. Simple group additivity rules fail to explain the observed distribution of sites of H-atom abstraction for simple formates.
U2 - 10.1002/kin.20498
DO - 10.1002/kin.20498
M3 - Journal article
SN - 0538-8066
VL - 42
SP - 479
EP - 498
JO - International Journal of Chemical Kinetics
JF - International Journal of Chemical Kinetics
IS - 8
ER -