Abstract: | Oxidation of zero‐valent phosphine complexes M(PtBu3)2] (M=Pd, Pt) has been investigated in 1,2‐difluorobenzene solution using cyclic voltammetry and subsequently using the ferrocenium cation as a chemical redox agent. In the case of palladium, a mononuclear paramagnetic PdI derivative was readily isolated from solution and fully characterized (EPR, X‐ray crystallography). While in situ electrochemical measurements are consistent with initial one‐electron oxidation, the heavier congener undergoes C?H bond cyclometalation and ultimately affords the 14 valence‐electron PtII complex Pt(κ2PC‐PtBu2CMe2CH2)(PtBu3)]+ with concomitant formation of Pt(PtBu3)2H]+. |