Analytical Study of the Combined Nitrogen Oxides and Ozone Systems and its Application to Organic Synthesis

较低的氮氧化物，如一氧化氮和二氧化氮，在臭氧的存在下被激活，与各种芳香化合物顺利反应，得到相应的单硝基或多硝基衍生物，收率很高。基于动力学研究和产物分析，发现这种新型芳香硝化反应是通过二氧化氮和臭氧原位相互作用形成的三氧化二氮作为初始亲电试剂进行的。当芳香族底物氧化电位较低时，三氧化氮氧化芳香族底物生成自由基阳离子，自由基阳离子被二氧化氮捕获形成硝基arenium离子，最终生成预期的硝基化合物。当芳香族底物氧化电位较高时，三氧化二氮与二氧化氮偶联形成五氧化二氮，五氧化二氮异解生成氮离子，遵循常规硝化过程。这种制备芳香硝化的非酸方法是非常有前途的，作为一种无污染的替代品，传统的，但目前正在进行的，基于使用硝酸和硫酸的商业过程。从交通繁忙的城市大气颗粒物中分离出一种高诱变致癌物3-硝基苯并蒽醌。在人工大气条件下，研究了二氧化氮与吸附在无机载体上的苯并蒽酮的反应。结果表明，三氧化二氮可能是一种负责大气硝化的活性物质。作为本工作的延伸，还研究了过氧亚硝酸盐对生物相关芳香物种的硝化作用。

Lower nitrogen oxides such as nitrogen monoxide and dioxide are activated in the presence of ozone to react smoothly with a wide variety of aromatic compounds to give the corresponding mononitro or polynitro derivatives in good yield. Based on the kinetic studies as well as the product analyses, this novel type of aromatic nitration has been found to proceed via nitrogen trioxide, formed in situ from the interaction of nitrogen dioxide and ozone, as the initial electrophile. When aromatic substrates are of low oxidation potential, nitrogen trioxide oxidizes an aromatic substrate to generate a radical cation, which is trapped by nitrogen dioxide to form the nitroarenium ion, eventually leading to the expected nitro compound. When aromatic substrates have high oxidation potentials, nitrogen trioxide couples with nitrogen dioxide to form dinitrogen pentaoxide, which undergoes heterolysis to generate the nitronium ion and follow the course of conventional nitration. This non-acid methodology for preparative aromatic nitration is highly promising as a pollution-free substitute for the classical, yet currently ongoing, commercial process based on the use of nitric and sulfuric acid.From the airborne particulate collected in traffic-heavy urban area, a highly mutagenic and carcinogenic substance was isolated and identified as 3-nitrobenzanthrone. The reaction of nitrogen dioxide with benzanthrone adsorbed on inorganic support has been investigated in the presence or absence of ozone under artificial atmospheric conditions. The results suggest a possible role of nitrogen trioxide as an active species responsible for atmospheric nitration. As an extension of the present work, the nitration of bio-related aromatic species with peroxynitrite has also been investigated.