Disproportionation of Xenate

We promised you challenging mechanisms in our introductory remarks (Section 8.1) and here is a good example. Consider reaction 8.27, which is the disproportionation of xenate 

Since oxidation implies electron donation, a reasonable answer to the last question is that we must use the lone pair on the xenon being oxidized to do a nucleophilic attack on one of the oxygens of another xenate, as shown below  

Observe how in one stroke we produced octavalent and tetravalent xenon, or equivalently in this case Xe(VIII) and Xe(IV). The octavalent Xe intermediate readily adds a hydroxide to form perxenate  

The reactions of the tetravalent xenon intermediate are a bit more complex. If we assume that the oxygens attached to the Xe are electrophilic and susceptible to attack by OH , then that would lead to the divalent intermediate Xe(OH)2 and H2O2, which is certainly a step in the right direction, namely, toward the final products Xe and O2  

Assuming that the oxygen atoms in Xe(OH)2 are electrophilic, we could have the hydroperoxide anion attack one of them, producing elemental xenon and H2O3 (trioxidane). 

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