Criegee自由基与有机胺的反应及其产物参与新粒子形成的机理研究

Criegee自由基(CIs)具有极强的氧化性，主要来自于烯烃臭氧化过程中产生，其单分子反应可产生OH等活性自由基，同时CIs又可以和OH自由基及多种大气污染物发生化学反应，在大气物质循环中起着不可替代的作用，并在大气化学反应中占据着举足轻重的地位。有机胺在大气中普遍存在，是二次有机气溶胶的重要前体物。本项目拟采用量子化学计算与分子模拟方法从分子水平上探讨典型CIs与有机胺的气相及气-液界面反应机理以及相应的动力学性质，明确速控步骤及主要产物；同时研究主要反应产物参与新粒子形成的机理，对其参与的中性成核、离子诱导成核的微观机理进行深入研究，探讨其形成的分子团簇的结构信息、能量信息、相互作用机理及平衡常数，并确定临界核的化学组成及粒径大小。期望通过本项目的研究为解释大气气溶胶中含氮化合物的来源，深入阐明大气中氮循环的途径，进而为有效控制二次气溶胶污染提供强的理论依据和科技支撑。

Criegee Intermediates (CIs) are highly oxidizing, mainly derived from the ozonolysis of alkenes. Its unimolecular reactions can produce active radicals such as OH radicals. Meanwhile, CIs can also react with OH radicals and a variety of atmospheric species, play an important role in the atmospheric material cycle, and have a pivotal role in atmospheric chemical reactions. Amines are ubiquitous in the atmosphere, and are important precursors of secondary organic aerosols (SOA). This project intends to use quantum chemical calculations and molecular simulation methods to explore the gas-phase and gas-liquid interface reaction mechanisms and corresponding kinetic properties of typical CIs and amines at the molecular level, and to clarify the speed control steps and main reaction products. At the same time, the mechanism of the main reaction products participating in the formation of new particles is studied, and the mechanisms of neutral nucleation and ion-induced nucleation are studied in depth. We will explore the structural information, energy information, interaction mechanism and equilibrium constants of the molecular clusters, and determine the chemical composition and particle size of the critical nucleus. The project intends to explain the sources of nitrogen-containing compounds in atmospheric aerosols, clarify the pathways of nitrogen cycle in the atmosphere, and then provide a strong theoretical basis and technical support for effective control of SOA.