Photochemistry of Oxygenated Organics

该项目涉及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）在近红外光谱区对过氧乙酰硝酸酯和羟甲基过氧化氢的光解量子产率进行实验室定量，并对这些物质以及过氧亚硝酸（HOONO）的泛音跃迁强度进行从头计算，（2）实验室测定了几种醛在紫外光谱区的吸收截面和光解量子产率，（3）利用地面太阳光谱沿着实验室对大气过氧亚硝酸和乙醛红外光谱的测量，（4）对甲醛在太阳光分解过程中形成的氢分子的同位素分馏进行测量，（5）对氧分子与乙烯氧自由基反应产生的羟基自由基产物进行定量的实验。 总之，这些研究将增进对有机氧化物和含氮物质在大气中的归宿的了解，并将导致提高预测其对自由基、臭氧和气溶胶丰度的影响的能力，这一项目的更广泛影响包括增进我们对与臭氧和气溶胶形成有关的大气过程的了解，从而导致更好的改善空气质量的战略。 这项研究还将为研究生和本科生提供教育和培训，并将通过其涉及化学家，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.