A family of luminescent coordination compounds: iridium(III) polyimine complexes

30 years of Ir-III coordination chemistry with polyimine-type ligands are summarized. Over the years, milder reaction conditions have been used for their synthesis, allowing the incorporation of various functional substituents. Complexes are described with bidentate and terdentate ligands, with both N- and C-donor sites. All complexes are luminescent, with predominantly charge-transfer or ligand-centred emissive states depending on the charge density donated from the ligands to the metal. Ir-III excited state lifetimes range from nanoseconds to microseconds. A wide range of properties are obtained: [IrN6](3+) complexes are strong photooxidants while tris-cyclometallated [IrN3C3] complexes are strong photoreductants.