Investigation on the Gas-Phase reaction of OH radicals with p-Toluidine

[Display omitted] •The path from p-toluidine to p-CH3-C6H4-•NH dominates with product yield up to 50%.•At high temperatures, the path from p-toluidine to p-•CH2-C6H4-NH2 prevails.•Compared to Toluene and Aniline: Toluene + OH < p-Toluidine + •OH< Aniline + •OH.•The atmospheric lifetime of p-toluidine is 3.7 hours, showing no impact on climate change. The CCSD(T)//M06-2X/6–311++G(3df,2p) level of theory was used to build the potential energy surface of the p-toluidine + •OHreaction. The calculated results show that p-CH3-C6H4-•NH is the key product if T=300–2000 K with branching ratios from 50 % to 36 %. At higher temperatures, p-•CH2-C6H4-NH2 prevails with product yield exceeding 34 %. Compared to the C6H5NH2 + •OH reaction, the present reaction is slower; however, it is faster than the reactions of toluene and m-toluidine with •OH radicals. The atmospheric lifetime of p-toluidine, 3.7 h, reveals that this compound can be lost quickly and has an insignificant impact on climate change.