Iridium(I) pyridyl azolate complexes with saturated red metal-to-ligand charge transfer phosphorescence; Fundamental and potential applications in organic light-emitting diodes

Chung Hong Fang, Yao Lun Chen, Cheng Han Yang, Yun Chi, Yu Shan Yeh, Elisa Y. Li, Yi Ming Cheng, Chia Jung Hsu, Pi Tai Chou, Chin Ti Chen

Research output: Contribution to journalArticle

4 Citations (Scopus)


Preparation of a new series of neutral metal complexes [(cod)Ir-(fppz)] (1), [(cod)Ir(bppz)] (2), [(cod)Ir(fptz)] (3) and [(cod)Ir(bptz)] (4). bearing one cod ligand and a pyridyl azolate chelate are reported. A single-crystal X-ray diffraction study of 3 reveals the expected distorted square-planar geometry. The lowest absorption band consists of Ir1 atom increased triplet dπ-→* transitions (3MLCT), the assignment of which is firmly supported by the theoretical approaches. Complexes 1-4 exhibit weak phosphorescence in degassed solution at room temperature, whereas much more intense, solid-state phosphorescence appears in the range 622-649 nm. The pure MLCT emission was used as a prototypical model to address its remarkable spectral differences from the IrIII isoquinoline pyrrolide complex (5), which has mainly 3ππ phosphorescence. Complex 3 was used as a dopant to fabricate red-emitting phosphorescent organic light-emitting diodes (OLEDs). For the 7% doped device, a maximum brightness of 3010 cdm-2 was achieved at an applied voltage of 15 V and with CIE coordinates of (0.56, 0.33). demonstrating for the first time the potential of neutral Ir1 complexes in OLED applications.

Original languageEnglish
Pages (from-to)2686-2694
Number of pages9
JournalChemistry - A European Journal
Issue number9
Publication statusPublished - 2007 Jan 1



  • Cyclooctene
  • Iridium
  • Phosphorescence
  • Photochemistry
  • Pyridyl azolate

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Cite this