Substituted benzoyl peroxides in which one of the moieties is p-methoxybenzoyl (anisoyl) and the other has one or more nitro substituents are known to decompose heterolytically as well as homolytically. In polar media the decomposition reactions are faster than those in non-polar media and the free radical derived products begin to be accompanied by ion pair derived products such as the carboxy inversion compound. The surface of silica favors the polar reaction more than do ordinary polar solvents. / The literature contains evidence that bis(p-methoxybenzoyl) peroxide (AP) may also react in part by a polar mechanism, even in relatively nonpolar solvents. The rate for the peroxide with a single p-methoxy substituent in dioxane also exceeds that predicted by the Hammett plot. The thermolysis of AP at room temperature in silica gel slurries made with nonpolar solvents is several orders of magnitude faster than the corresponding reaction in solution. The rate is dependent on the choice of solvent, the type of silica gel, and the loading of the silica gel surface. The major initial product of the decomposition is the carboxy inversion product, anisoyl anisyl carbonate (APCI). The reaction was followed by conventional methods, as well as solid state $\sp{13}$C NMR spectroscopy. / The products from the decomposition of benzoyl peroxide (BP) in ordinary solvents (excluding those due to reaction with the solvent) are the acid, ester and carbon dioxide. The thermolysis of BP on silica gel in the absence of solvent at 40$\sp\circ$ was about 22 times as fast as the rate calculated for a dilute benzene solution at that temperature and gave products derived almost entirely from ionic precursors. Thermolysis on silica gel at 80$\sp\circ$ was only about 3 times as fast as the reaction in benzene and gave products derived largely from radical and only to a lesser extent from ionic precursors. Photolysis at 25$\sp\circ$ gave only radical-derived products. / Source: Dissertation Abstracts International, Volume: 50-08, Section: B, page: 3475. / Major Professor: John E. Leffler. / Thesis (Ph.D.)--The Florida State University, 1989.
| Identifer | oai:union.ndltd.org:fsu.edu/oai:fsu.digital.flvc.org:fsu_78064 |
| Contributors | Flowers, George Craig., Florida State University |
| Source Sets | Florida State University |
| Language | English |
| Detected Language | English |
| Type | Text |
| Format | 72 p. |
| Rights | On campus use only. |
| Relation | Dissertation Abstracts International |
Page generated in 0.0024 seconds