Chemical Activation Reaction Dibenzofuranyl

Master equation analysis for Fall-off is performed on the DBF + O2 reaction system to estimate the rate constants and to determine the important reaction paths as a function of temperature and pressure. 

The BFY(C5J) + CO2 contribution which is still of importance in this system is relatively low compared to the other channels. BFY(C5JO) + CO formation is less important in this system. 

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Because of the active phenyl radical contained in the dibenzofliranyl structure, we consider that the dibenzofuranyl + O2 reaction system behaves the same way as the phenyl + O2 system. On this basis we have constructed a potential energy surface for the reaction of dibenzofuranyl radical + O2 as illustrated in Figure 7.8. The major features of this surface are very similar to those calculated for the phenyl + O2 system. As for the phenyl system, there are five reactions of high importance in the chemical activation (bimolecular reaction) of dibenzofuranyl + O2 ... 

The dibenzofuranyl + O2 association results in a chemically activated dibenzofuranyl-peroxy radical with a 50 kcal mof well depth at 298K. This chemically activated adduct can dissociate to phenoxy + O, or react back to phenyl + O2. Both channels have a relatively loose transition states and their barriers are near that of the entrance channel. The dibenzofuranyl + O2 reaction association can also undergo intramolecular addition of the peroxy radical to several unsaturated carbon sites on the ring via more tight transition states. The reaction to benzofuran-phenoxy + O has a significantly lower barrier of about 10 kcal mof below the entrance channel. 

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