Spectroscopic Studies of Homogeneous Precursors to Atmospheric Acids and Aerosols

大气酸和气溶胶均相前体的光谱研究

• 批准号: 9322809
• 负责人: Kenneth Leopold
• 金额: $ 14.96万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1994
• 资助国家: 美国
• 起止时间: 1994-08-15 至 1998-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9322809&HistoricalAwards=false
• 关键词: Spectroscopic; Studies; Homogeneous; Precursors; Atmospheric

A newly constructed, pulsed-nozzle Fourier transform microwave spectrometer will be used to determine the structures, dipole moments, and reaction energetics of a variety of gaseous species that are precursors to certain atmospheric aerosols and acids. Particular emphasis will be placed on adducts of sulfur trioxide (SO3), which is the immediate precursor to sulfuric acid (H2SO4) in the atmosphere. Additional studies will focus on complexes involving water vapor, sulfur trioxide, ammonia, sulfur dioxide, sulfuric acid, nitrogen oxides, and nitric acid. The data from these spectroscopic investigations will provide new molecular-level detail about the chemical mechanisms that produce sulfuric acid and nitric acid aerosols. Because aerosols influence the earth's albedo and precipitation patterns, this research will impact our understanding of climate. Many of the adducts targeted for study are expected to involve bonding forces that are intermediate between van der Waals and covalent. Consequently, this research will explore the role of unconventional bonding in complexes involved in postulated processes of atmospheric importance. Extensions of the initial project will include studies of radical intermediates and selected tertiary clusters that represent the next step beyond dimers in the homogeneous nucleation process.

新建造的脉冲喷嘴傅立叶变换微波光谱仪将用于确定作为某些大气气溶胶和酸的前体的各种气态物质的结构、偶极矩和反应能量。 将特别强调三氧化硫 (SO3) 的加合物，它是大气中硫酸 (H2SO4) 的直接前体。 其他研究将集中于涉及水蒸气、三氧化硫、氨、二氧化硫、硫酸、氮氧化物和硝酸的复合物。 这些光谱研究的数据将提供有关产生硫酸和硝酸气溶胶的化学机制的新的分子水平细节。 由于气溶胶影响地球的反照率和降水模式，这项研究将影响我们对气候的理解。 许多用于研究的加合物预计涉及介于范德华力和共价键之间的键合力。 因此，这项研究将探讨非常规键合在参与假定的大气重要过程的复合物中的作用。 初始项目的扩展将包括对自由基中间体和选定的三级簇的研究，它们代表了均质成核过程中超越二聚体的下一步。