LAUSR

Abstract Guaiacol is the main representative of methoxyphenols generated from the pyrolysis of ligin. The gas-phase reaction mechanism of guaiacol with NO3 radical was researched by using density functional theory at M06-2X/6-31+g(d,p)//M06-2X/6-311+g(3df,2p) level in this work, and the reaction rate constants were calculated by using RRKM theory. The relative complete gas phase reaction mechanism of guaiacol with nitrate radicals was obtained. The calculated results showed that, NO3 addition and H abstraction are two dominant progresses for the initial reaction of guaiacol with NO3 radicals. The total reaction rate constant is 3.11 × 10−11 cm3 molecule−1 s−1 at 298 K and 1 atm. The atmospheric lifetime is 64 s under typical tropospheric concentration of NO3 radicals. The possibility of products (methoxybenzoquinone and nitro-guaiacol) is verified and new products (dialdehyde and diketone) are predicted.