The Benzylperoxyl Radical as a Source of Hydroxyl and Phenyl Radicals. Issue 40 (21st August 2014)

• Record Type: Journal Article
• Authors: Sander, Wolfram; Roy, Saonli; Bravo‐Rodriguez, Kenny; Grote, Dirk; Sanchez‐Garcia, Elsa
• Is Part Of: Chemistry. Volume 20:Issue 40(2014)
• Page Start: 12917
• Page End: 12923
• Publication Date: 2014-08-21
• Subjects: Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.201402459
• Languages: English
• ISSNs: 0947-6539

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <p>The benzyl radical (<bold>1</bold>) is a key intermediate in the combustion and tropospheric oxidation of toluene. Because of its relevance, the reaction of <bold>1</bold> with molecular oxygen was investigated by matrix‐isolation IR and EPR spectroscopy as well as computational methods. The primary reaction product of <bold>1</bold> and O₂ is the benzylperoxyl radical (<bold>2</bold>), which exists in several conformers that can easily interconvert even at cryogenic temperatures. Photolysis of radical <bold>2</bold> at 365 nm results in a formal [1, 3]‐H migration and subsequent cleavage of the OO bond to produce a hydrogen‐bonded complex between the hydroxyl radical and benzaldehyde (<bold>4</bold>). Prolonged photolysis produces the benzoyl radical (<bold>5</bold>) and water, which finally yield the phenyl radical (<bold>7</bold>), CO, and H₂O. Thus, via a sequence of exothermic reactions <bold>1</bold> is transformed into radicals of even higher reactivity, such as OH and <bold>7</bold>. Our results have implications for the development of models for the highly complicated process of combustion of aromatic compounds.</p> </abstract>