Structural and Mechanistic Investigations of the Oxidation of Dimethylplatinum(II) Complexes by Dioxygen

The oxidation of (tmeda)PtII(CH3)2 (1, tmeda = N,N,N‘,N‘-tetramethylethylenediamine) to (tmeda)PtIV(OH)(OCH3)(CH3)2 (3) by dioxygen in methanol proceeds via a two-step mechanism. The initial reaction between (tmeda)Pt(CH3)2 and dioxygen yields a hydroperoxoplatinum(IV) intermediate, (tmeda)Pt(OOH)(OCH3)(CH3)2 (2), which reacts with a second equivalent of (tmeda)Pt(CH3)2 to afford the final product 3. Both 2 and 3 have been fully characterized, including X-ray crystallographic structure determinations. The effect of ligand variation on the oxidation of several dimethylplatinum(II) complexes by 2 as well as by dioxygen has been examined.