mer-Ir(pmi)3 is expected as fac isomers of such cyclometalated Ir(III) complexes are the thermodynamically more stable isomers, 66 and calculations have revealed a higher energy barrier to access their 3 MC states. This high thermal and photostability of Iridium(III) NHC complexes is well-documented in the context of emitter design for OLEDs, and this behavior seems to be operational in solution as well.