Kjærgaard Eva R, Møller Kristian H, Kjaergaard Henrik G
Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen Ø, Denmark.
J Phys Chem A. 2023 Nov 9;127(44):9311-9321. doi: 10.1021/acs.jpca.3c04509. Epub 2023 Oct 25.
Recently, hydroperoxy amides were identified as major products of OH-initiated autoxidation of tertiary amines in the atmosphere. The formation mechanism is analogous to that found for ethers and sulfides but substantially faster. However, the atmospheric fate of the hydroperoxy amides remains unknown. Using high-level theoretical methods, we study the most likely OH-initiated oxidation pathways of the hydroperoxy and dihydroperoxy amides derived from trimethylamine autoxidation. Overall, we find that the OH-initiated oxidation of the hydroperoxy amides predominantly leads to the formation of imides under NO-dominated conditions and more highly oxidized hydroperoxy amides under HO-dominated conditions. Unimolecular reactions are found to be surprisingly slow, likely due to the restricting, planar structure of the amide moiety.
最近，氢过氧酰胺被确定为大气中叔胺羟基引发自氧化的主要产物。其形成机制与醚和硫化物的类似，但速度要快得多。然而，氢过氧酰胺在大气中的归宿仍然未知。我们使用高级理论方法，研究了由三甲胺自氧化衍生的氢过氧酰胺和二氢过氧酰胺最可能的羟基引发氧化途径。总体而言，我们发现，在以一氧化氮为主导的条件下，氢过氧酰胺的羟基引发氧化主要导致酰亚胺的形成，而在以羟基为主导的条件下，则导致更高氧化态的氢过氧酰胺的形成。发现单分子反应出奇地缓慢，这可能是由于酰胺部分的平面结构具有限制作用。
