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In Search of High‐Performance Platinum( II ) Phosphorescent Materials for the Fabrication of Red Electroluminescent Devices
Author(s) -
Kavitha J.,
Chang S.Y.,
Chi Y.,
Yu J.K.,
Hu Y.H.,
Chou P.T.,
Peng S.M.,
Lee G.H.,
Tao Y.T.,
Chien C.H.,
Carty A. J.
Publication year - 2005
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200400131
Subject(s) - phosphorescence , materials science , oled , ligand (biochemistry) , electroluminescence , dopant , crystallography , stacking , platinum , photochemistry , nanotechnology , optoelectronics , fluorescence , chemistry , doping , catalysis , optics , physics , receptor , organic chemistry , layer (electronics) , biochemistry
The rational design and syntheses of Pt(iqdz) 2 ( 1 ) and Pt(pydz) 2 ( 2 ) bearing isoquinolinyl indazole (iqdz)H or pyridyl indazole (pydz)H groups on the coordinating ligands are reported. Single‐crystal X‐ray diffraction studies of 1 reveal a square planar geometry, in which two iqdz ligands adopt a trans‐configuration. Short N…H contacts (∼2.21 Å) are detected between the ortho‐hydrogen atom of isoquinoline and the adjacent N atom of the indazole fragment, making the overall molecular geometry analogous to that of the platinum( II ) porphyrinato complexes. The lowest absorption bands for both complexes reveal strong state mixings between singlet and triplet (metal‐to‐ligand charge transfer and intra‐ligand) manifolds. This, in combination with the introduction of a camphor‐like structure to avoid the stacking effect, leads to phosphorescence with unprecedented brightness both in solution and in the solid state. Organic light‐emitting diode (OLED) devices fabricated using 1 as a dopant emitter have been achieved in a multilayer configuration. The results constitute the first highly efficient Pt II ‐based red OLED.