Nitration of pyrene adsorbed on silica particles by nitrogen dioxide under simulated atmospheric conditions

Article abstract of DOI:10.1016/S0045-6535(99)00086-7

Nitration of adsorbed pyrene on silica particles with nitrogen dioxide was studied under condition of room light in a simulated atmosphere. An induction period was present in the nitration process. Nitric acid formed on the silica particles acted as the catalyst, and the reaction proceeded autocatalytically. Electron-donating substituents promoted the reaction, while the electron-attracting substituents diminished it. An electrophilic nitration mechanism involving HNO₂⁺ and HN₂O₄⁺ as electrophiles was proposed for the reaction. Nitration of adsorbed pyrene on silica particles with nitrogen dioxide was studied under condition of room light in a simulated atmosphere. An induction period was present in the nitration process. Nitric acid formed on the silica particles acted as the catalyst, and the reaction proceeded autocatalytically. Electron-donating substituents promoted the reaction, while the electron-attracting substituents diminished it. An electrophilic nitration mechanism involving HNO₂⁺ and HN₂O₄⁺ as electrophiles was proposed for the reaction.