Near-IR phosphorescent ruthenium(II) and iridium(III) perylene bisimide metal complexes.

Abstract

The phosphorescence emission of perylene bisimide derivatives has been rarely reported. Two novel ruthenium(II) and iridium(III) complexes of an azabenz-annulated perylene bisimide (ab-PBI), [Ru(bpy)2 (ab-PBI)][PF6 ]2 1 and [Cp*Ir(ab-PBI)Cl]PF6 2 are now presented that both show NIR phosphorescence between 750-1000 nm in solution at room temperature. For an NIR emitter, the ruthenium complex 1 displays an unusually high quantum yield (Φp ) of 11 % with a lifetime (τp ) of 4.2 μs, while iridium complex 2 exhibits Φp <1 % and τp =33 μs. 1 and 2 are the first PBI-metal complexes in which the spin-orbit coupling is strong enough to facilitate not only the Sn →Tn intersystem crossing of the PBI dye, but also the radiative T1 →S0 transition, that is, phosphorescence.