Light-Emitting Tridentate Cyclometalated Platinum(II) Complexes Containing -Alkynyl Auxiliaries: Tuning of Photo- and Electrophospho
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- 作者：Wei Lu ; Bao-Xiu Mi ; Michael C. W. Chan ; Zheng Hui ; Chi-Ming Che ; Nianyong Zhu ; and Shuit-Tong Lee
- 刊名：Journal of the American Chemical Society
- 出版年：2004
- 出版时间：April 21, 2004
- 年：2004
- 卷：126
- 期：15
- 页码：4958 - 4971
- 全文大小：491K
- 年卷期：v.126,no.15(April 21, 2004)
- ISSN：1520-5126
文摘
The synthesis and structural, photophysical, electrochemical, and electroluminescent propertiesof a class of platinum(II) complexes bearing 
-alkynyl ancillary ligands, namely [(C
NN)Pt(C
C)nR][H(CNN) = 6-aryl-2,2'-bipyridine; n = 1-4; R = aryl, alkyl, or trimethylsilyl], have been studied. Substituentswith different steric and electronic properties were introduced into the tridentate cyclometalating andarylacetylide ligands, and the 
-conjugation length of the oligoynyl moiety was homologously extendedfrom ethynyl to octatetraynyl. The X-ray crystal structures of several derivatives confirm the Pt-(CC)ligation and reveal various intermolecular interactions, such as -, Pt···Pt, and C-H···F-C. The complexesdisplay good thermal stability and intense phosphorescence in fluid and glassy solutions with high quantumyields and microsecond lifetimes. Their emission energies are sensitive to solvent polarity, the electronicaffinities of the substituents on both the cyclometalating and arylacetylide groups, and the length of theoligoynyl ligand. By choosing appropriate cyclometalating and -alkynyl ligands, the emission color of thisclass of platinum(II) complexes can be tuned from green-yellow to saturated red. In addition to 3MLCT[Pt(5d) 
*(CNN)] and 3IL(CNN), intriguing 3IL(alkynyl) excited states localized on -(CC)4- and-(CCpyrenyl-1) moieties that afford narrow-bandwidth emissions have been observed. Selected Pt(II)complexes were doped into the emissive region of multilayer, vapor-deposited organic light-emitting diodes.The tunable electrophosphorescence energy resembles that recorded in fluid solutions for these emitters,and the devices exhibit high luminance and efficiencies (up to 4.2 cd A-1).
-alkynyl ancillary ligands, namely [(CNN)Pt(CC)nR][H(CNN) = 6-aryl-2,2'-bipyridine; n = 1-4; R = aryl, alkyl, or trimethylsilyl], have been studied. Substituentswith different steric and electronic properties were introduced into the tridentate cyclometalating andarylacetylide ligands, and the -conjugation length of the oligoynyl moiety was homologously extendedfrom ethynyl to octatetraynyl. The X-ray crystal structures of several derivatives confirm the Pt-(CC)ligation and reveal various intermolecular interactions, such as -, Pt···Pt, and C-H···F-C. The complexesdisplay good thermal stability and intense phosphorescence in fluid and glassy solutions with high quantumyields and microsecond lifetimes. Their emission energies are sensitive to solvent polarity, the electronicaffinities of the substituents on both the cyclometalating and arylacetylide groups, and the length of theoligoynyl ligand. By choosing appropriate cyclometalating and -alkynyl ligands, the emission color of thisclass of platinum(II) complexes can be tuned from green-yellow to saturated red. In addition to 3MLCT[Pt(5d) *(CNN)] and 3IL(CNN), intriguing 3IL(alkynyl) excited states localized on -(CC)4- and-(CCpyrenyl-1) moieties that afford narrow-bandwidth emissions have been observed. Selected Pt(II)complexes were doped into the emissive region of multilayer, vapor-deposited organic light-emitting diodes.The tunable electrophosphorescence energy resembles that recorded in fluid solutions for these emitters,and the devices exhibit high luminance and efficiencies (up to 4.2 cd A-1).