Scheme 2. Qualitative energy diagram of (a) [Ir(dpqx)₂(Me₂-bpy)](PF₆) and bpy-Rho; and (b) Ir-Rho-G2 illustrating the population of the rhodamine-based triplet excited state (T₁). The energy levels of S₁ and were estimated by the on-sets of their emission energies.