Bis bipyridyl cobalt II

The oxidation of 2,6-DTBP by molecular oxygen is catalyzed by bis(bipyridyl)cobalt(II) in MeOH under ambient conditions [54]. The products are the corresponding p-benzoquinone (BQ) and diphenoquinone (DPQ). BQ is favored over DPQ at higher concentrations of the cobalt-dioxygen complex, which is generated in situ by saturating bis(bipyridyl)cobalt(II) with O. The equilibria described by 

Formation of the dibridged n-peroxo complex has been reported earlier [55], 

Kinetic studies of phenol oxidation revealed the rate law  

The essential features of the mechanism proposed for this catalytic reaction are in agreement with those of earlier reaction schemes [27,36]. The cycle begins with H-atom abstraction from the phenol by the dinuclear dibridged p-peroxo species, generating a phenoxy radical and subsequently HO  

Significantly, no H-abstraction by the superoxo or the nonbridged /Li-peroxo species is assumed, the latter playing no role whatsoever in the cycle. The superoxo complex is involved in a reaction with the phenoxy radical, which is the path for 0-atom incorporation into the phenol, via formation of a peroxyquinolatocobalt(III) complex  

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