TY - JOUR
T1 - Mechanisms for the reactions of OH with two unsaturated aldehydes
T2 - Crotonaldehyde and acrolein
AU - Orlando, John J.
AU - Tyndall, Geoffrey S.
PY - 2002/12/26
Y1 - 2002/12/26
N2 - The mechanisms for the reaction of OH with the unsaturated aldehydes, acrolein and crotonaldehyde, have been determined at 1 atm total pressure in the presence of NOx using an environmental chamber/FTIR spectrometer system. Products observed in the OH-initiated oxidation of acrolein were CO, CO2, CH2O, HOCH2CHO (glycolaldehyde), and HCOOH, while the major products identified in the OH-initiated oxidation of crotonaldehyde were CO, CO2, CH3CHO, and HC(O)CHO (glyoxal). Also observed were two PAN-type species, identified as CH2=CH-C(O)O2NO2 (APAN) from acrolein oxidation and CH3-CH=CH-C(O)O2NO2 (CPAN) from crotonaldehyde. The near-complete mass balance obtained in these experiments allows for a quantitative assessment of the branching ratios for abstraction and addition in these reactions. It is shown that about 68% (50%) of the OH reaction with acrolein (crotonaldehyde) proceeds via abstraction of the aldehydic H, with the remainder occurring via addition to the double bond. The data allow for a more accurate assessment of the atmospheric source strength of APAN, a species which has now been identified in ambient air. Trends in the reactivity of acrolein and its methylated derivatives, methacrolein and crotonaldehyde, are also discussed; data are shown to be consistent with structure-reactivity considerations.
AB - The mechanisms for the reaction of OH with the unsaturated aldehydes, acrolein and crotonaldehyde, have been determined at 1 atm total pressure in the presence of NOx using an environmental chamber/FTIR spectrometer system. Products observed in the OH-initiated oxidation of acrolein were CO, CO2, CH2O, HOCH2CHO (glycolaldehyde), and HCOOH, while the major products identified in the OH-initiated oxidation of crotonaldehyde were CO, CO2, CH3CHO, and HC(O)CHO (glyoxal). Also observed were two PAN-type species, identified as CH2=CH-C(O)O2NO2 (APAN) from acrolein oxidation and CH3-CH=CH-C(O)O2NO2 (CPAN) from crotonaldehyde. The near-complete mass balance obtained in these experiments allows for a quantitative assessment of the branching ratios for abstraction and addition in these reactions. It is shown that about 68% (50%) of the OH reaction with acrolein (crotonaldehyde) proceeds via abstraction of the aldehydic H, with the remainder occurring via addition to the double bond. The data allow for a more accurate assessment of the atmospheric source strength of APAN, a species which has now been identified in ambient air. Trends in the reactivity of acrolein and its methylated derivatives, methacrolein and crotonaldehyde, are also discussed; data are shown to be consistent with structure-reactivity considerations.
UR - https://www.scopus.com/pages/publications/0037180729
U2 - 10.1021/jp021530f
DO - 10.1021/jp021530f
M3 - Article
AN - SCOPUS:0037180729
SN - 1089-5639
VL - 106
SP - 12252
EP - 12259
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 51
ER -