119th General Meeting of the KCS

Type Poster Presentation
Area 공업화학
Room No. 포스터발표장
Time 4월 20일 (목요일) 11:00~12:30
Code IND.P-3
Subject Photophysical Properties of Isomeric Blue Phosphorescent Ir(III) Complexes with Cyclometalated Carbene Ligands
Authors 윤보선, 강상욱, 손호진*
고려대학교 신소재화학과, Korea
Abstract Improvement of the stability of blue phosphorescent dopant material is one of the key factor for real application of organic light-emitting diodes. In particular, imidazole ligand of Ir(III) complex tend to play an important role in the stability of blue phosphorescence. In addition, N-heterocyclic carbene (NHC) ligands, or Ir(C∧C:)3 known for thermodynamically stable. We report a study of the synthesis and photophysical properties of cyclometalated iridium complexes, some of which emit in the blue part of the spectrum, with N-heterocyclic carbene ligands: [Ir(dmfmi)3], Iridium, tris[(9,9-dimethyl-9H-fluorene-3,2-diyl)(3-methyl-1H-imidazol-1-yl-2(3H)-ylidene)]. Imidazolyl-carbene ligand has a stronger trans influence than (C∧N) ligand and, thus, imparts a greater ligand field strength. Both mer-Ir(dmfmi)3 and fac-Ir(dmfmi)3 complexes display strong metal-to-ligand-charge-transfer absorption transitions in the UV (λ = 270-370 nm) and phosphorescene in the blue region (E0-0 = 455 nm, 467 nm) at room temperature. The meridional and facial isomers show different spectroscopic properties each other and meridional isomers leads to the observation that they are easier to oxidize, exhibit red-shifted emission, and have lower quantum efficiencies than their facial isomers.
E-mail yunbosun@korea.ac.kr