Electron and proton magnetic resonance spectroscopic investigation of anthracene oxidation
The work reports a method for monitoring anthracene radical-mediated oxidation reactions using electron paramagnetic resonance (EPR) spectroscopy. The formation of anthracene dimer product was well-defined using 1H-NMR and 1H–1H correlation spectroscopy (COSY). Unrestricted 3-21G/B3LYP DFT was used...
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Veröffentlicht in: | Heliyon 2021-11, Vol.7 (11), p.e08474-e08474, Article e08474 |
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Format: | Artikel |
Sprache: | eng |
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Zusammenfassung: | The work reports a method for monitoring anthracene radical-mediated oxidation reactions using electron paramagnetic resonance (EPR) spectroscopy. The formation of anthracene dimer product was well-defined using 1H-NMR and 1H–1H correlation spectroscopy (COSY). Unrestricted 3-21G/B3LYP DFT was used to estimate radical hyperfine spacing (hfs), then to identify the characteristic EPR-spin transitions of anthracene radical intermediate. A detailed investigation of an anthracene oxidation reaction and its possible reaction mechanism in concentrated sulphuric acid is conducted as a model system for polyaromatic hydrocarbons. Peak-to-peak (p2p) intensities of selected EPR-spectral lines were used to evaluate anthracene's oxidation kinetic model. The findings showed that radical intermediate formation is a unimolecular autocatalytic process, dimerization is a pseudo-zero-order reaction, and the latter is the rate-determining step with a half-life of 48 ± 2 min at 25.0 °C.
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EPR Spectroscopy; NMR Spectroscopy; Anthracene cation radical; Radical kinetics. |
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ISSN: | 2405-8440 2405-8440 |
DOI: | 10.1016/j.heliyon.2021.e08474 |