In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes
In situ EPR spectroscopy at cryogenic temperatures has been used to observe and identify paramagnetic species produced when titania is irradiated in the presence of reactants used in the photocatalytic alkylation of maleimide with t-butyl carboxylic acid or phenoxyacetic acid. It is shown that malei...
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| Format: | Article |
| Language: | English |
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MDPI AG
2015-03-01
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| Series: | Molecules |
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| Online Access: | http://www.mdpi.com/1420-3049/20/3/4055 |
| _version_ | 1819156902641139712 |
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| author | Shona Rhydderch Russell F. Howe |
| author_facet | Shona Rhydderch Russell F. Howe |
| author_sort | Shona Rhydderch |
| collection | DOAJ |
| description | In situ EPR spectroscopy at cryogenic temperatures has been used to observe and identify paramagnetic species produced when titania is irradiated in the presence of reactants used in the photocatalytic alkylation of maleimide with t-butyl carboxylic acid or phenoxyacetic acid. It is shown that maleimide acts as an acceptor of conduction band electrons. Valence band holes oxidise t-butyl carboxylic acid to the t-butyl radical and phenoxyacetic acid to the phenoxyacetic acid radical cation. In the presence of maleimide, the phenoxymethyl radical is formed from phenoxyacetic acid. The relevance of these observations to the mechanisms of titania photocatalyst-promoted alkylation of alkenes is discussed. |
| first_indexed | 2024-12-22T16:00:15Z |
| format | Article |
| id | doaj.art-e4df67f6730c419aa523b791e561da35 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-12-22T16:00:15Z |
| publishDate | 2015-03-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-e4df67f6730c419aa523b791e561da352022-12-21T18:20:43ZengMDPI AGMolecules1420-30492015-03-012034055407010.3390/molecules20034055molecules20034055In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of AlkenesShona Rhydderch0Russell F. Howe1Chemistry Department, University of Aberdeen, Aberdeen AB24 3UE, UKChemistry Department, University of Aberdeen, Aberdeen AB24 3UE, UKIn situ EPR spectroscopy at cryogenic temperatures has been used to observe and identify paramagnetic species produced when titania is irradiated in the presence of reactants used in the photocatalytic alkylation of maleimide with t-butyl carboxylic acid or phenoxyacetic acid. It is shown that maleimide acts as an acceptor of conduction band electrons. Valence band holes oxidise t-butyl carboxylic acid to the t-butyl radical and phenoxyacetic acid to the phenoxyacetic acid radical cation. In the presence of maleimide, the phenoxymethyl radical is formed from phenoxyacetic acid. The relevance of these observations to the mechanisms of titania photocatalyst-promoted alkylation of alkenes is discussed.http://www.mdpi.com/1420-3049/20/3/4055EPR spectroscopytitaniaphotocatalysisalkene alkylation |
| spellingShingle | Shona Rhydderch Russell F. Howe In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes Molecules EPR spectroscopy titania photocatalysis alkene alkylation |
| title | In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes |
| title_full | In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes |
| title_fullStr | In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes |
| title_full_unstemmed | In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes |
| title_short | In Situ EPR Studies of Reaction Pathways in Titania Photocatalyst-Promoted Alkylation of Alkenes |
| title_sort | in situ epr studies of reaction pathways in titania photocatalyst promoted alkylation of alkenes |
| topic | EPR spectroscopy titania photocatalysis alkene alkylation |
| url | http://www.mdpi.com/1420-3049/20/3/4055 |
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