The selective catalytic oxidation of methane and higher alkanes remains one of the great challenges in catalysis research. Considerable progress has been made during the last three decades regarding the CÀH activation of alkanes, in particular electrophilic activation reactions with late transition metals. [1][2][3][4] Once C À H bond cleavage has occurred at a metal center, a functionalization of the metal-carbon bond is required, followed by release of the product and regeneration of the catalyst. In the case of oxidation reactions, this functionalization of metal-alkyl complexes should be carried out ideally with environmentally benign oxidants such as O 2 or H 2 O 2 . We previously reported the oxidation of dimethylplatinum(II) complexes with H 2 O 2 to generate cis-dihydroxoplatinum(IV) complexes.[5] The unusual cis isomer was obtained by using amino-substituted bipyridine ligands, which stabilize this isomer through hydrogen bonding. When we extended our work to methylplatinum(II) complexes containing tridentate amino-substituted terpyridine (terpy) ligands, we discovered a remarkable reactivity of the complexes towards O 2 .The reaction of 6,6'-diaminoterpyridine (1) (1)]. The rate of the O 2 insertion reaction is affected by light: Whereas the reaction proceeds within several minutes at room temperature in ambient light, the reaction is very slow in the absence of light and only 50 % conversion is obtained after 13 h at room temperature.