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

在臭氧存在下活化低级氮氧化物如一氧化氮和二氧化物，与各种芳族化合物顺利反应，以高产率得到相应的一硝基或多硝基衍生物。基于动力学研究以及产物分析，这种新型的芳香族硝化已被发现进行通过三氧化二氮，从二氧化氮和臭氧的相互作用，在原位形成的初始亲电试剂。当芳族底物具有低氧化电位时，三氧化二氮氧化芳族底物以产生自由基阳离子，其被二氧化氮捕获以形成硝基芳烃离子，最终导致预期的硝基化合物。当芳香族底物具有高氧化电位时，三氧化二氮与二氧化氮偶联形成五氧化二氮，五氧化二氮经历异裂解以产生硝鎓离子并遵循常规硝化过程。这种制备芳香族硝化的非酸方法是非常有前途的，作为一个无污染的替代经典的，但目前正在进行的，商业过程的基础上使用硝酸和硫酸。从交通繁忙的城市地区收集的空气中的颗粒物，高度致突变和致癌物质被分离和鉴定为3-硝基苯并蒽酮。在人工大气条件下，研究了NO2与吸附在无机载体上的苯并蒽酮在臭氧存在和不存在下的反应。结果表明，一个可能的作用，三氧化二氮作为一个活跃的物种负责大气硝化。作为本工作的延伸，生物相关的芳香物种与过氧亚硝酸根硝化也进行了研究。

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.