Atmospherically Relevant Electronic States of O2 and Their Isotopes

O2 及其同位素的大气相关电子态

• 批准号: 9612366
• 负责人: Tom Slanger
• 金额: $ 29.97万
• 依托单位: SRI International
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-02-01 至 2000-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9612366&HistoricalAwards=false
• 关键词: Atmospherically; Relevant; Electronic; States; O2

9612366 Slanger Excited states of molecular oxygen are ubiquitous throughout the atmosphere, and their spectroscopy, radiative properties, and kinetics are essential elements in determining the photophysics and photochemistry of atmospheric regions. In this project, three areas will be investigated: a) kinetics and reactivity of the O2(b) state in vibrationally excited levels, b) weakly bound but potentially important states of O2 lying near the dissociation limit, and c) exploration of isotope effects in O2 photoabsorption in the 242-250 nm Herzberg band absorption region. The O2(b) state has been studied primarily in its lowest vibrational level, yet there are indications of stratospheric sources involving much higher vibrational levels, and their kinetic properties could be important. The weakly-bound states of O2 have been discussed in various contexts, yet there are no relevant measurements. The technique of cavity ring-down spectroscopy is making it possible to investigate these states, which are implicated as precursors in both laboratory and atmospheric phenomena. Variability in atmospheric oxygen isotope ratios in ozone, carbon dioxide, and nitrous oxide are of current interest, and cavity ring-down studies may be helpful in explaining these effects. ***

9612366分子氧的Slanger激发态在大气中普遍存在，它们的光谱、辐射性质和动力学是决定大气区域光物理和光化学的基本元素。在这个项目中，将研究三个领域：a)O2(B)态在振动激发能级中的动力学和反应性，b)O2在解离极限附近的弱结合但潜在的重要状态，以及c)在242-250 nm Herzberg带吸收区域O2光吸收中的同位素效应的探索。人们主要研究O2(B)态的最低振动能级，但有迹象表明，平流层的源包含更高的振动能级，它们的动力学性质可能很重要。O2的弱束缚态在不同的背景下已经被讨论过，但还没有相关的测量结果。腔衰荡光谱技术使研究这些状态成为可能，这些状态在实验室和大气现象中都被认为是前兆。臭氧、二氧化碳和一氧化二氮中大气氧同位素比率的变化是当前感兴趣的问题，而空穴衰荡研究可能有助于解释这些影响。***