Creosol and 4-ethylguaiacol are two important methoxyphenols, lignin pyrolysis products, which are discharge into the atmosphere in large quantities. In this work, theoretical calculations of the reaction mechanism towards the two compounds with NO₃ radicals was performed using DFT method. The rate constants and toxicity assessment were also investigated. The atmospheric lifetime for creosol and 4-ethylguaiacol were 0.82 and 0.19 h, respectively. A new reaction pathway was proposed for the transformation of methoxyl into hydroxyl, which has not yet been clarified in previous studies. The toxicity of methoxyphenols and their degradation products is closely related to their hydrophobicity. Although most degradation products are less toxic, they also should be pay more attention, especially for nitro-substituents.

A new reaction pathway was proposed for the transformation of methoxyl into hydroxyl. The toxicity is closely related to their hydrophobicity.

甲酚和4-乙基愈创木酚是两种重要的甲氧基酚，木质素热解产物，它们大量排放到大气中。在这项工作中，对两种具有NO _3的化合物的反应机理的理论计算自由基是使用DFT方法进行的。还研究了速率常数和毒性评估。甲酚和4-乙基愈创木酚的大气寿命分别为0.82和0.19h。提出了一种新的反应途径，用于将甲氧基转化为羟基，在先前的研究中尚未阐明。甲氧基苯酚及其降解产物的毒性与其疏水性密切相关。尽管大多数降解产物的毒性较小，但也应引起更多关注，尤其是对于硝基取代基。

提出了一种新的反应途径，用于将甲氧基转化为羟基。毒性与其疏水性密切相关。