β-Phenyl quenching of 9-phenylphenalenones: A novel photocyclisation reaction with biological implications
| Autor: | Teresa A. Grillo, Javier G. Luis, Carme Brosa, Goetz Bucher, Cristina Flors, Santi Nonell, Roger Bresolí-Obach |
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| Rok vydání: | 2014 |
| Předmět: |
Quenching (fluorescence)
Magnetic Resonance Spectroscopy Hydrogen Light Chemistry Substituent Molecular Conformation General Physics and Astronomy chemistry.chemical_element Nuclear magnetic resonance spectroscopy Ketones Phenalenes Ring (chemistry) Photochemistry Carbon Oxygen chemistry.chemical_compound Cyclization Excited state Quantum Theory Spectrophotometry Ultraviolet Phenylphenalenones Singlet state Physical and Theoretical Chemistry |
| Zdroj: | Repositorio Institucional del Instituto Madrileño de Estudios Avanzados en Nanociencia instname |
| Popis: | The singlet and triplet excited states of 9-phenylphenalenones 1 undergo β-phenyl quenching (BPQ) via addition of the carbonyl oxygen to the ortho position of the phenyl substituent. This reaction leads to the formation of naphthoxanthenes 4, which, in the absence of quenchers, undergo a very rapid electrocyclic ring opening reaction reverting to 1 within a few microseconds. Naphthoxanthene 4a contains a remarkably weak C–H bond, which enables efficient hydrogen transfer reactions to suitable acceptors, giving rise to the production of the naphthoxanthenyl radical or the naphthoxanthenium cation, depending on the solvent polarity. The study uncovers a number of new aspects of BPQ and suggests an excited state-mediated metabolic pathway in the biosynthesis of plant fluorones. |
| Databáze: | OpenAIRE |
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