Blue to True-Blue Phosphorescent IrIII Complexes Bearing a Nonconjugated Ancillary Phosphine Chelate: Strategic Synthesis, Photophysics, and Device Integration

We report the design and synthesis of Ir-III complexes functionalized with substituted pyridyl cyclometalate or-azolate chromophores plus one newly designed nonconjugated phoshine chelate, which not only greatly restricts its participation on in the lowest-lying electronic transition but also enhances the coordination strength. These two key factors lead to fine tuning of the phosphorescence chromaticity toward authentic blue and simultaneously suppress, in part, the nonradiative deactivation. This conceptual design presents a novel strategy in achieving heretofore uncommon, high-efficiency blue and true blue phosphorescence. The fabrication of the organic light-emitting devices (OLEDs) employing phosphorescent dopants [Ir(dfpbpy)(2) (pn) and was successfully made, for which the abbreviations together with a ture-blue chromaticity cie(x,y) = 0.163, with 0.145 recorded at 100 cd m(-2).