Reactions of NO3 with aromatic aldehydes: gas-phase kinetics and insights into the mechanism of the reaction

Yangang Ren (1) , Li Zhou (1) , Abdelwahid Mellouki (1) , Véronique Daële (1) , Mahmoud Idir (1) , Steven Brown (2) , Branko Ruscic (3) , Robert Paton (4) , Max Mcgillen (1) , A. Ravishankara (1, 4, 5)

1 ICARE - Institut de Combustion, Aérothermique, Réactivité et Environnement
2 CSL - NOAA Chemical Sciences Laboratory
3 ANL - Argonne National Laboratory [Lemont]
4 Department of Chemistry, Colorado State University
5 Department of Atmospheric Science [Fort Collins]

Abstract. Rate coefficients for the reaction of NO3 radicals with a series of aromatic aldehydes were measured in a 7300 L simulation chamber at ambient temperature and pressure by relative and absolute methods. The rate coefficients for benzaldehyde (BA), ortho-tolualdehyde (O-TA), meta-tolualdehyde (M-TA), para-tolualdehyde (P-TA), 2,4-dimethyl benzaldehyde (2,4-DMBA), 2,5-dimethyl benzaldehyde (2,5-DMBA) and 3,5-dimethyl benzaldehyde (3,5-DMBA) were k1= 2.6 ± 0.3, k2= 8.7 ± 0.8, k3= 4.9 ± 0.5, k4= 4.9 ± 0.4, k5= 15.1 ± 1.3, k6= 12.8 ± 1.2 and k7= 6.2 ± 0.6, respectively, in the units of 10−15 cm3 molec.−1 s−1 at 298 ± 2 K. The rate coefficient k13 for the reaction of the NO3 radical with deuterated benzaldehyde (benzaldehyde-d1) was found to be half that of k1. The end product of the reaction in an excess of NO2 was measured to be C6H5C(O)O2NO2. Theoretical calculations of aldehydic bond energies and reaction pathways indicate that the NO3 radical reacts primarily with aromatic aldehydes through the abstraction of an aldehydic hydrogen atom. The atmospheric implications of the measured rate coefficients are briefly discussed.

Domaines: Autre; Chimie théorique et/ou physique

Yangang Ren, Li Zhou, Abdelwahid Mellouki, Véronique Daële, Mahmoud Idir, et al.. Reactions of NO3 with aromatic aldehydes: gas-phase kinetics and insights into the mechanism of the reaction. Atmospheric Chemistry and Physics, 2021, 21 (17), pp.13537-13551. ⟨10.5194/acp-21-13537-2021⟩. ⟨hal-03346223⟩