title: Gas-Phase Reactions of Methoxyphenols with NO3 Radicals: Kinetics, Products, and Mechanisms.
abstract: Methoxyphenols, a group of important tracers for wood smoke, are emitted to the atmosphere in large quantities, but their transformations are rarely studied. In this study, the kinetics and products of the gas-phase reactions of eugenol and 4-ethylguaiacol with NO3 radicals were investigated online using a vacuum ultraviolet photoionization gas time-of-flight mass spectrometer. The rate coefficients of the gaseous reactions of eugenol and 4-ethylguaiacol with NO3 radicals were (1.6 ± 0.4) × 10(-13) and (1.1 ± 0.2) × 10(-12) cm(3) molecule(-1) s(-1) (at 298 K), indicating that the atmospheric lifetimes of the NO3 radicals were 3.5 and 0.5 h, respectively. With the aid of gas-chromatography-mass-spectrometry analysis, several types of degradation products were identified with nitro derivatives as the major products. The configurations of the nitro-product isomers and their formation mechanisms were determined via theoretical calculations. On the basis of these products, degradation pathways of the methoxyphenols with NO3 radicals were proposed. This study determines the degradation rates and mechanisms of the methoxyphenols at night and implies the significant NO3 nighttime chemistry.
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Haixu
authors: H
authors: Zhang
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Bo
authors: B
authors: Yang
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Youfeng
authors: Y
authors: Wang
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Jinian
authors: J
authors: Shu
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Peng
authors: P
authors: Zhang
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Pengkun
authors: P
authors: Ma
authors: State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing 100085, China.
authors: Zhen
authors: Z
authors: Li