| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 65818 | Journal of Molecular Catalysis A: Chemical | 2013 | 6 Pages |
The remarkable effect of simple aliphatic alcohols on the controlled oxidation of toluene with molecular oxygen over [5,10,15,20-tetrakis(p-chlorophenyl)porphinato]manganese fluoride (T(p-Cl)PPMnF) and N-hydroxyphthalimide (NHPI) was reported. The influences of reaction conditions such as the concentration and structure of alcohols, temperature and catalyst concentration on the promotion effect were also studied. UV–vis spectra were used to investigate the possible structure of reaction intermediate derived from the catalyst (T(p-Cl)PP)MnF in the toluene oxidation systems in the presence of methanol. The results showed that the added methanol interacted with catalyst (T(p-Cl)PP)MnF to form the coordination compound [(T(p-Cl)PP)MnIII(ROH)2]+, which subsequently was transformed into a high valent manganese-oxo radical cation intermediate [(T(p-Cl)PP)MnIV(O)(CH3OH)]+ in the oxidation systems. We deduce that the formation of [(T(p-Cl)PP)MnIV(O)(CH3OH)]+ and its higher reactivity toward toluene may be responsible for the better results observed. On the basis of the results obtained, a possible mechanism of the controlled oxidation of toluene with dioxygen over (T(p-Cl)PP)MnF/NHPI in the presence of the aliphatic alcohols was proposed.
Graphical abstractFigure optionsDownload full-size imageDownload high-quality image (129 K)Download as PowerPoint slideHighlights► Toluene aerobic oxidation catalyzed by T(p-Cl)PPMnF/NHPI. ► Aliphatic alcohols markedly affect catalytic activity of T(p-Cl)PPMnF/NHPI. ► Controlled toluene oxidation to benzaldehyde and benzyl alcohol. ► Alcohols facilitate the formation of [(T(p-Cl)PP)MnIV(O)(CH3OH)]+.
