Chemistry of water-soluble Pt-diimine complexes relevant to C-H bond activation

Detailed mechanistic studies of selective catalytic alkane oxidation with Pt complexes have revealed that the reaction pathway includes the following steps: Initial C-H bond activation at a Pt(ll) center leads to formation of a Pt(ll) alkyl complex which in turn is oxidized in the second step to a hexacoordinate Pt(IV) species. Most mechanistic studies have been carried out with Pt-complex bearing bidentate N-ligands (diamines, diimines) in non-aqueous solvents, while the early work by Shilov et al. on Pt-catalyzed hydrocarbon functionalization was carried out in aqueous solution. To relate the diaminel diimine model chemistry to the Shilov chemistry in water, the water-soluble Pt-complex 1 was prepared. The results of synthetic and mechanistic studies of 1 in water will be presented