《Cationic Iridium Complexes with 3,4,5-Triphenyl-4H-1,2,4-Triazole Type Cyclometalating Ligands: Synthesis, Characterizations, and Their Use in Light-Emitting Electrochemical Cells》 was published in Inorganic Chemistry in 2020. These research results belong to Meng, Xianwen; Chen, Mengzhen; Bai, Rubing; He, Lei. Quality Control of 4,4′-Dimethyl-2,2′-bipyridine The article mentions the following:
Cationic Ir complexes that show blue-shifted emission and high phosphorescent efficiency were pursued for their optoelectronic applications. Five cationic Ir complexes with 3,4,5-triphenyl-4H-1,2,4-triazole (tPhTAZ) type cyclometalating ligands (C^N) and 2,2′-bipyridine or 2-(pyridin-2-yl)-1H-benzo[d]imidazole type ancillary ligands (N^N) were designed and synthesized. Their structures were confirmed by x-ray crystallog., and their photophys. and electrochem. properties were comprehensively characterized. In solution and thin films, the complexes afford efficient yellow to blue-green emission. The highest occupied MOs (HOMOs) of these complexes are delocalized over the C^N ligand and the Ir ion, and compared with the conventional 2-phenylpyridine (Hppy) ligand, the tPhTAZ ligand largely shifts the emission of the complex toward blue by over 40 nm through stabilizing the HOMO. Also, the peripheral Ph rings in tPhTAZ provide steric hindrance to the complexes, which suppresses phosphorescence concentration-quenching of the complexes, leading to high luminescent efficiencies in neat films. Theor. calculations showed that the emission of the complexes originates from either the charge-transfer state (Ir/C^N → N^N) or the C^N/N^N-centered 3π-π* state, depending on the local surrounding of the complex. The complexes exhibit good electrochem. stability with reversible oxidation and reduction processes in solution Solid-state light emitting electrochem. cells (LECs) using the complexes afford yellow to blue-green emission, with peak current efficiencies of up to 34.7 cd A-1 and maximum brightness of up to 256 cd m-2 at 3.0 V, which are among the highest for LECs based on cationic Ir complexes reported so far, indicating the great potential for the use of tPhTAZ-type C^N ligands in construction of cationic Ir complexes for LEC applications. tPhTAZ-type cyclometalating ligands (tPhTAZ is 3,4,5-triphenyl-4H-1,2,4-triazole) blue-shift the emission and suppress phosphorescence-concentration quenching for cationic Ir complexes, leading to highly efficient blue-green to yellow light-emitting electrochem. cells (LECs) with efficiencies of up to 34.7 cd A-1. In the experiment, the researchers used many compounds, for example, 4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6Quality Control of 4,4′-Dimethyl-2,2′-bipyridine)
4,4′-Dimethyl-2,2′-bipyridine(cas: 1134-35-6) is used as a chemical Intermediate. It can be used for the determination of ferrous and cyanide compounds.Quality Control of 4,4′-Dimethyl-2,2′-bipyridine Furthermore, 4,4′-Dimethyl-2,2′-bipyridine is used in the synthesis of a series of o-phenanthroline-substituted ruthenium(II) complexes.