Upon the addition of Br2 to complexes (P-P)Pt(Ar)2, two different products were observed, depending on the bite angle of the bidentate phosphine ligand: a Pt(II) aryl bromide complex, the product of C-Br reductiveelimination, and Pt(IV) oxidative addition complex. At high temperatures, the latter exclusively gave the product of the C-C reductiveelimination.