Photochemistry of Oxygenated Organics

该项目包括通过实验室和理论光化学研究以及大气观测，对选定的含氧和含氮有机化合物进行调查。这些研究将包括：(1)近红外光谱区过氧乙酰硝酸盐和羟甲基氢过氧化氢的光解量子产率的实验室量化，以及这些物质和过氧亚硝酸（HOONO）泛音跃迁强度的从头计算，(2)紫外光谱区一些醛的吸收截面和光解量子产率的实验室测量。(3)利用地面太阳光谱测量大气中的过氧亚硝酸盐（HOONO）和乙醛，并在实验室测量这些物质的红外光谱；(4)测量甲醛在太阳光解过程中形成的分子氢的同位素分馏；(5)实验量化分子氧与氧自由基反应的羟基自由基产物收率。总之，这些研究将提高对有机含氧和含氮物种的大气命运的理解，并将提高预测它们对自由基、臭氧和气溶胶丰度的影响的能力。这个项目更广泛的影响包括提高我们对与臭氧和气溶胶形成有关的大气过程的理解，从而导致更好的策略来改善空气质量。这项研究还将为研究生和本科生提供教育和培训，并将通过化学家、地球化学家和物理学家的合作性质得到加强。

This project involves investigation of selected oxygenated and nitrogen-containing organic compounds through laboratory and theoretical photochemical studies, and atmospheric observations. The studies will involve (1) laboratory quantification of photolysis quantum yields of peroxyacetyl nitrate, and hydroxylmethyl hydroperoxide in the near-infrared spectral region along with ab initio calculations of the strengths of the overtone transitions of these species as well as peroxynitrous acid (HOONO), (2) laboratory measurement of absorption cross sections and photolysis quantum yields for a number of aldehydes in the ultraviolet spectral region, (3) measurement of atmospheric peroxy nitrous acid (HOONO) and acetaldehyde using ground-based solar spectra along with laboratory measurement of infrared spectra of these species, (4) measurements of the isotopic fractionation of molecular hydrogen formed in the solar photolysis of formaldehyde, and (5) experiments to quantify the hydroxyl radical product yield from the reaction of molecular oxygen with vinoxy radicals. Together, these studies will improve understanding of the atmospheric fate of organic oxygenated and nitrogen-containing species, and will lead to enhanced capability to predict their impact on free radical, ozone and aerosol abundances.The broader impacts of this project include improving our understanding of atmospheric processes related to ozone and aerosol formation, and thus leading to better strategies for improvement of air quality. This research will also provide education and training for graduate and undergraduate students, and will be enhanced by its collaborative nature involving chemists, geochemists and physicists.