title: The new iridium complexes involving pyridylpyridine derivatives for the saturated blue emission.
abstract: To obtain a saturated blue phosphorescent material with a good color purity, we have synthesized the new blue emitting iridium complexes with 2, 6-difluoro-3-(4-methylpyridin-2-yl)pyridine (4-Me-dfpypy) as a main ligand. We expected that the LUMO energy levels of the complex might increase upon introduction of an electron donating group such as a methyl group to the pyridyl moieties of the ligand, leading to a wide energy gap of the complex to give the saturated blue emission. We have also introduced a variety of the ancillary ligands to the iridium center to compare the effect of the ancillary ligards on the emission of their complexes. The resulting iridium complexes, Ir(4-Me-dfpypy)3, Ir(4-Me-dfpypy)2(acac), Ir(4-Me-dfpypy)2(pic) and Ir(4-Me-dfpypy)2(trzl-CH3) where acac, pic, and trzl-CH3 represent acetylacetonate, picolinate, and 2-(5-methyl-2H-1,2,4-triazol-3-yl) pyridinate, respectively exhibited the blue emission at 451, 447, 440 and 425 nm in CH2Cl2 solution. The organic light emitting device (OLED) employing homoleptic Ir(4-Me-dfpypy), as the blue dopant was prepared and their electroluminescence was investigated. Ir(4-Me-dfpypy)3 exhibited the blue emission of CIE coordinates (0.22, 0.32).
authors.affiliation: Department of Information Display Engineering, Hongik University, Seoul 121-791, Korea.
authors.forename: Hye Rim
authors.initials: HR
authors.lastname: Park
authors.forename: Dong Hwan
authors.initials: DH
authors.lastname: Lim
authors.forename: Young Kwan
authors.initials: YK
authors.lastname: Kim
authors.forename: Yunkyoung
authors.initials: Y
authors.lastname: Ha
mesh_terms: D003116:Color; D004867:Equipment Design; D019544:Equipment Failure Analysis; D008029:Lighting / Q000295:instrumentation*; D011725:Pyridines / Q000737:chemistry*; D012666:Semiconductors
chemical_list: D011725:Pyridines