We report the electrochemical, photoluminescence, and electroluminescence properties of four fluorinated cationic iridium complexes bearing pyridyltriazole ancillary ligands. All the complexes display unstructured emission in the true blue region at 298 K with photoluminescent l em ranging from 452 to 487 nm in acetonitrile solution, in powder and in PMMA doped thin films. The nature of the emission is a mixed metal-to-ligand/ligand-to-ligand charge transfer state. Photoluminescence (PL) quantum efficiencies both in solution and in the solid state were low while excited state decay kinetics were found to be multiexponential. Each complex undergoes quasi-reversible oxidation and irreversible reduction with large HOMO-LUMO gaps. A detailed computational investigation corroborates the spectroscopic assignments. Additionally, light-emitting electrochemical cells (LEECs) were fabricated for each of the four complexes. The electroluminescence (EL) spectra of all complexes were red-shifted relative to the PL spectra. The LEEC containing 2a is the bluest emitter (l max ¼ 487 nm) of the family of complexes.

Two strongly blue luminescent cationic heteroleptic iridium complexes 1b and 2b bearing a 4,4′‐bis(dimethylamino)‐2,2′‐bipyridine (dmabpy) ancillary ligand and either 1‐benzyl‐4‐(2,4‐difluorophenyl)‐1H‐1,2,3‐triazole (dFphtl) or 2‐(2,4‐difluorophenyl)‐5‐methylpyridine (dFMeppyH), respectively, have been synthesized and fully characterized. In comparison with other analogues, the interplay of the triazole unit with the dmabpy unit and methylation of the pyridine ring are discussed with respect to the photophysical, electrochemical, and electrochemiluminescent (ECL) properties of the complexes. The two complexes, 1b and 2b, are blue emitters with λmax = 495 and 494 nm, respectively. The nature of the excited states was established by various photophysical and photochemical experiments as well as DFT calculations. Both complexes emit from a ligand‐centered state, however, the emission of 1b possesses significant charge‐transfer character, which is absent in 2b. The presence of the methyl group on the cyclometalating ligand leads only to a modest increase in the radiative rate constant, kr, but otherwise does not appreciably influence the optoelectronic properties of the complex compared with the non‐methylated analogue. In contrast, the efficacy of the ECL emission when scanning to 2.50 V is strongly influenced by the presence of the methyl group. ECL emission is also enhanced in complexes bearing dmabpy ancillary ligands compared with those containing dtBubpy ligands. The two complexes exhibit similar electrochemical behavior. Incorporation of the dmabpy ligand shifts both the oxidation and reduction cathodically. The combination of the dmabpy and dFphtl groups increases the redox potential difference and thus the HOMO–LUMO gap but the emission is not further blueshifted. Thus, the structural modification of the cyclometalating ligand, although only modestly tuning the emission energy, modulates the nature of the excited state and the efficiency of the ECL process.

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Substituted polyhydroquinolines are ubiquitous skeletal cores found in drugs and bioactive natural products. As a new route to access this motif, we successfully developed a one-pot cyclization cascade with high chemocontrol and diastereoselectivity. The sequence generates two cycles, three carbon–carbon bonds, and an all-carbon quaternary center in a highly convergent process. Functionalized polyhydroquinolines and congeners can be accessed from commercially available amino acids. This versatile and robust strategy was applied to the synthesis of (±)-Δ7-mesembrenone.