Deprotonation induced ligand-to-metal electron transfer: Synthesis of a mixed-valence Rh(-I,I) dinuclear compound and its reaction with dioxygen

Treatment of bis(2-picolyl)amine (bpa) with [{Rh(nbd)(μ-OMe)}2] leads to the unexpected and unique redox asymmetric dinuclear Rh−I,Rh+I complex [{Rh(nbd)}2(bpa-2H)] (2) with a π-coordinating imine bound to a tetrahedral low valent rhodate(−I). Mono-oxygenation of the deprotonated bpa ligand in 2 by O2 leads to the mononuclear carboxamido complex [Rh(nbd)(bpam-H)] (3) (bpam = N-(2-picolyl)picolinamide). The second O atom of O2 ends up as a hydroxo fragment in [{Rh(nbd)(μ-OH)}2].The generous financial support from MEC/FEDER (Project CTQ2005-06807), DGA (PIP019 and Research Group E70) (Spain), and The Netherlands Organization for Scientific Research (NWO-CW) is gratefully acknowledged. M.P.R. thanks DGA for a fellowship.Peer reviewe