Ti-oxo radicals and product selectivity in olefin oxidations over titanosilicate molecular sieves
| Title | Ti-oxo radicals and product selectivity in olefin oxidations over titanosilicate molecular sieves |
| Publication Type | Journal Article |
| Year of Publication | 2005 |
| Authors | Shetti, VN, Srinivas, D, Ratnasamy, P |
| Journal | Zeitschrift für Physikalische Chemie International Journal of Research in Physical Chemistry and Chemical Physics |
| Volume | 219 |
| Issue | 7 |
| Pagination | 905-920 |
| Date Published | JUL |
| Type of Article | Article |
| ISSN | 0942-9352 |
| Keywords | cyclic voltammetry of titanosilicates, EPR-spin trap experiments, Molecular sieves, oxidations, product selectivity, reactive oxygen species, titaniunz-oxo radicals, Titanosilicates |
| Abstract | The O-O bond of Ti-oxo species (Ti-peroxo, Ti-hydroperoxo or Ti-superoxo) generated on titanosilicate molecular sieves contacted with H2O2 cleaves either heterolytically or homolytically. While the former type of O-O cleavage (generating non-radical reactive oxygen intermediates) leads to selective epoxide products, the latter (generating reactive oxygen radical intermediates, O-2(-center dot) and HOOcenter dot) results in non-sclective, allylic oxidation products in cyclohexene oxidation. These radicals were detected using EPR spin trapping techniques 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) was used as the spin trap. Radical quenchers like hydroquinone suppressed their concentration and enhanced epoxide selectivity. |
| DOI | 10.1524/zpch.219.7.905.67088 |
| Type of Journal (Indian or Foreign) | Foreign |
| Impact Factor (IF) | 1.133 |
Divison category:
Catalysis and Inorganic Chemistry