Photochemistry of trichloro(phenylazo)bis(triphenylphosphine)ruthenium(II) induced by Ru to phenyldiazonium MLCT excitation

The complex trichloro(phenylazo)bis(triphenylphosphine)ruthenium(II) shows a longest-wavelength absorption at λmax = 520 nm which is assigned to a Ru(II) → phenyldiazonium+ MLCT transition. MLCT excitation leads to the oxidation of the metal and reduction of the diazonium cation which decays to nitrogen and phenyl radical.