PHOTOREDOX REACTION OF (P-DIMETHYLAMINOPYRIDINE)OSMIUM(VIII)TETROXIDEINDUCED BY LIGAND-TO-METAL CHARGE-TRANSFER EXCITATION

The complex OsO4(4-dimethylaminopyridine) shows a long-wavelength adso rption at lambda(max)=473 nm which is assigned to a ligand-to-metal ch arge transfer (LMCT) transition from the pyridine ligand to Os(VIII). LMCT excitation of the complex dissolved in ethanol leads to a reducti on of Os(VIII) to Os(VI) and oxidation of ethanol to acetaldehyde with phi=0.1 at lambda(irr)=436 nm.