1998 Fiscal Year Final Research Report Summary
Analytical Study of the Combined Nitrogen Oxides and Ozone Systems and its Application to Organic Synthesis
| Project/Area Number |
08101003
|
|---|
| Research Category |
Grant-in-Aid for Specially Promoted Research
|
| Allocation Type | Single-year Grants |
|---|
| Review Section |
Chemistry
|
|---|
| Research Institution | KYOTO UNIVERSITY |
|---|
Principal Investigator |
SUZUKI Hitomi Graduate School of Science, Kyoto University, Professor, 大学院・理学研究科, 教授 (50025342)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MURASHIMA Takasi Faculty of Science, Ehime University, Assistant, 理学部, 助手 (20263923)
|
|---|
| Project Period (FY) |
1996 – 1998
|
| Keywords | Nitrogen oxides / Nitration / Ozone / Nitro compounds / Aromatic compounds / Reaction mechanism / Pollution / Carcinogen |
|---|
| Research Abstract |
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.
|
