Rhodium-dioxygen complexes, aqueous

The rhodium complexes cis- and irans-[Rh(eda)2(N02 )X]+, where X = N02, or ON , photoreact (182) with dioxygen in aqueous solution to form monomeric [Rh(eda)2(H20)(02)]2+ and dimeric complexes. These complexes act as one-electron oxidizing agents, oxidizing 1 to I2 and Fe11 to Fe111. 

The rhodium complex [CpRh(bipy)Cl2] is reported (162) to act as one-half of a redox couple that, in concert with a manganese porphyrin system, catalyzes the epoxidation of olefins by dioxygen. In this two-phase system, the aqueous phase contains sodium formate, and the organic phase is a trichloroethane solution of [Mnm(tpp)]1+ and the rhodium complex (tpp = meso-tetraphenylporphyrin). Apparently, the rhodium complex catalyzes the reduction of [Mnin(tpp)]1+ by formate, and the manganese(II) species thus formed binds dioxygen and reacts with the substrate olefin to form the epoxide. However, the intermedi-... 

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