New Phosphorescent Cyclometalated Iridium(III) Complexes with Diphenyl-1,3-oxazolic and 2-(3-Thienyl)pyridine Ligands for LED Applications

  • Kirsyuk, V. V. (Laboratory for Advanced Molecular Processing, Dep. of Chemical Engineering, Pohang University of Science and Technology) ;
  • Turgambaeva, A. E. (Laboratory for Advanced Molecular Processing, Dep. of Chemical Engineering, Pohang University of Science and Technology) ;
  • Shim, Jung-Jin (Laboratory for Advanced Molecular Processing, Dep. of Chemical Engineering, Pohang University of Science and Technology) ;
  • Rhee, Shi-Woo (Laboratory for Advanced Molecular Processing, Dep. of Chemical Engineering, Pohang University of Science and Technology)
  • Published : 2003.07.09

Abstract

We report four new phosphorescent iridium(III} complexes with 2,4-diphenyl-1,3-oxazole [$Ir(24dpo)_3$], 2,5-diphenyl-1,3-oxazole [$Ir(25dpo)_3$], 2-(3-thienyl) pyridine [$Ir(3thpyh)_3$] and [Ir(3thpy)2(acac)]. Three of them demonstrate good photophysical properties to be used as dopants to organic polymer matrix or to be used "as is" without a host matrix to fabricate OLEDs. Green and yellow light emission was observed for the photoluminescence: 569/525, 549/498 nm and 557,604/533 (solid state/$CH_2Cl_2$ solution) for $Ir(24dpo)_3$, $Ir(3thpyh)_3$ and $Ir(3thpyh)_2$acac respectively. Room temperature luminescent lifetimes are 2.5 and 1.8 ${\mu}s$ and quantum efficiencies 37 and 53%for $Ir(24dpo)_3$ and $Ir(3thpyh)_3$. The complexes are stable in air and sublimable at low pressure without considerable decomposition. Comparison of physicochemical properties of the reported iridium(III) cyclometalated compounds with that known from literature is carried out.

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