Kinetics and Photochemistry of Atmospheric Aldehyde Reactions

小行星9610285 该项目的主要目标是确定大气醛反应的动力学及其光化学。醛是影响烟雾过程的光化学反应的主要参与者;它们的光解离是对流层光化学中自由基和有机气溶胶的主要来源。尽管醛的光解在对流层的化学的重要性，醛的光解产物的通道和量子产率的研究很少已经进行了在大气条件下或在条件下，可以很容易地推断到那些大气。自由基，如甲酰基自由基，在大气中很容易转化为过氧化氢和羟基自由基，它们参与光化学氧化过程。 在本项目中，将对具有五个或更多碳原子的醛、芳香醛和二羰基化合物的光解进行研究。的光解产物通道和量子产率的特点，以及它们对光解波长的依赖。对于同系的醛类化合物，将提取烷基侧链的结构与光解量子产率之间的关系。实验研究将采用脉冲激光光解结合灵敏的光吸收技术-光腔衰荡光谱法进行。除了光解研究，醛形成反应的动力学和机制，如甲氧基自由基与分子氧的反应，将得到阐明。

9610285 Zhu The primary objective of this project is to determine the kinetics of atmospheric aldehyde reactions and their photochemistry. Aldehydes are key participants in photochemical reactions affecting smog processes; their photodissociation represents a major source of free radicals and organic aerosols for tropospheric photochemistry. Despite the importance of aldehyde photolysis in the chemistry of the troposphere, few studies of aldehyde photolysis product channels and quantum yields have been carried out either under atmospheric conditions or under conditions that can be readily extrapolated to those of the atmosphere. Free radicals, such as formyl radicals, are readily converted in the atmosphere to hydroperoxyl and hydroxyl radicals, which participate in photochemical oxidation processes. In this project, studies of the photolysis of aldehydes with five carbon atoms or more, aromatic aldehydes, and dicarbonyls, will be carried out. The photolysis product channels and quantum yields will be characterized, as well as their dependence on photodissociation wavelengths. The relationship between the structure of alkyl side chains and photolysis quantum yields will be extracted for homologous series of aldehydes. The experimental studies will be carried out using pulsed laser photolysis coupled with a sensitive optical absorption technique, cavity ring-down spectroscopy. In addition to the photolysis studies, the kinetics and mechanisms of aldehyde formation reactions, such as the reaction of the methoxy radical with molecular oxygen, will be elucidated.