Highly Emissive Red Heterobimetallic Ir^III/M^I (M^I = Cu^I and Au^I) Complexes for Efficient Light-Emitting Electrochemical Cells

A class of four bright heterobimetallic emitters is presented, which features both a chromophoric [Ir(C^N)2] center and positively charged, linear bis-NHC M(I) ancillary moiety bridged through Janus-type ligand. An in-depth investigation their optical electrochemical properties also reported, are further elucidated by means time-dependent density functional theory including spin–orbital coupling effects. All complexes display efficient, vibrant red phosphorescence with higher quantum yield faster radiative rate constant compared to the mononuclear parental complexes. This effect was in terms better S–T excited-state mixing as well increased rigidity favored multimetallic architecture. Finally, electroluminescence performances investigated using these bimetallic electroactive materials light-emitting cells, achieving external efficiency values up 6% resulting among most efficient ones for emitters. result attributable charge-neutral nature an emitting Ir complex bearing wider energy gap, metal moiety.