Dioxygen reactivity with a ferrocene-Lewis acid pairing: reduction to a boron peroxide in the presence of tris(pentafluorophenyl)borane.

Ferrocenes, which are typically air-stable outer-sphere single-electron transfer reagents, were found to react with dioxygen in the presence of B(C6 F5 )3 , a Lewis acid unreactive to O2 , to generate bis(borane) peroxide. Although several Group 13 peroxides have been reported, boron-supported peroxides are rare, with no structurally characterized examples of the BO2 B moiety. The synthesis of a bis(borane)-supported peroxide anion and its structural and electrochemical characterization are described.