Laser photolysis studies of ω-bond dissociation in aromatic carbonyls of five-membered rings induced by triplet sensitization
| Autor: | Shota Fujino, Minoru Yamaji, Bronislaw Marciniak |
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| Rok vydání: | 2018 |
| Předmět: |
Quantitative Biology::Biomolecules
Absorption spectroscopy 010405 organic chemistry General Chemical Engineering General Physics and Astronomy General Chemistry 010402 general chemistry Photochemistry 01 natural sciences Dissociation (chemistry) 0104 chemical sciences chemistry.chemical_compound chemistry Excited state Furan Ultrafast laser spectroscopy Physics::Atomic and Molecular Clusters Thiophene Phenyl group Physics::Chemical Physics Bond cleavage |
| Zdroj: | Journal of Photochemistry and Photobiology A: Chemistry. 365:39-44 |
| ISSN: | 1010-6030 |
| DOI: | 10.1016/j.jphotochem.2018.07.028 |
| Popis: | Photoinduced ω-bond cleavage was investigated in seven newly synthesized aromatic ketones having five-membered rings (furan and thiophene) and/or phenyl group connected to the phenylthiyl moiety with C S bond. Following direct laser excitation of these ketones in acetonitrile, the transient absorption spectra that appeared were shown to be due to the corresponding triplet states. No chemical reactions occurred upon direct excitation. However, triplet sensitization of these aromatic ketones using xanthone revealed no formation of their triplet states. Instead absorption spectra of the phenylthiyl radical (PTR) appeared as a result of C S bond cleavage. These observations indicate that higher triplet states were reactive leading to C S bond dissociation. The C S bond dissociation mechanism upon triplet sensitization for the studied carbonyl compounds was discussed considering energy diagrams of the higher excited states. |
| Databáze: | OpenAIRE |
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