Dual Luminescence, Interligand Decay, and Nonradiative Electronic Relaxation of Cyclometalated Iridium Complexes in Solution

Femtosecond broadband photoluminescence studies are presented for Ir(ppy)(3) (Ir1), Ir(ppy)(2)(pic) (Ir2), Ir(ppy)(2)(bpy)(PF6) (Ir3), Ir(ppz)(3) (Ir4), and Ir(ppz)(2)dipy (Ir5) (where ppy = 2-phenylpyridine, pic = picolinate, bpy = 2,2'-bipyridine, ppz = 1-phenylpyrazole, and dipy = 5-phenyldipyrrinato) in solution. Upon 400-nm excitation of Ir1-Ir3, we observed a prompt population of the lowest MLCT states. The higher states decay on an ultrafast time scale (