Electron and proton magnetic resonance spectroscopic investigation of anthracene oxidation. Issue 11 (November 2021)

• Record Type: Journal Article
• Authors: Morsy, Mohamed A.; Kawde, Abdel-Nasser M.; Kamran, Muhammad; Garrison, Thomas F.; Iali, Wissam; Alharthi, Salman S.
• Is Part Of: Heliyon. Volume 7:Issue 11(2021)
• Publication Date: 2021-11
• Subjects: EPR Spectroscopy -- NMR Spectroscopy -- Anthracene cation radical -- Radical kinetics; Research -- Periodicals; Medical sciences -- Periodicals; Natural history -- Periodicals; Social sciences -- Periodicals; Earth sciences -- Periodicals; Physical sciences -- Periodicals; 507.2
• DOI: 10.1016/j.heliyon.2021.e08474
• Languages: English
• ISSNs: 2405-8440

Abstract

Abstract: 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 1 H-NMR and 1 H– 1 H 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. Graphical abstract: Image 1 Abstract : EPR Spectroscopy; NMR Spectroscopy; Anthracene cation radical; Radical kinetics.