Radical rebound mechanism, methane

The radical rebound mechanism has been proposed and proved in several cases in reaction of hydroxylation catalyzed by cytochrome 450 and methane monooxigenase (Section 3.2)... 

Whereas several transient species have been observed for dioxygen activation by MMOH, no intermediates were found by rapid-mixing spectroscopic methods for the actual methane hydroxylation step. Mechanistic probes, i.e. certain non-natural substrates that are transformed into rearranged products only if the reaction proceeds via a specific intermediate such as a radical or a cation, give ambivalent results Some studies show that products according to a pathway via cationic intermediates are obtained in sMMO hydroxylations and at least one study suggests the presence of a radical intermediate [40]. Computational analyses of the reaction of MMOHq with methane suggest a so-called radical recoil/rebound mechanism in which MMOHq... 

Figure 7 Schematic diagram for two-state rebound mechanism for methane hydroxylation by an oxoiron(IV) porphyrin rr-cation radical (after Ogliaro et...

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