Synthesis And Photoluminescent Properties Of Red And Green Light-emitting Complexes With Fluorinated 2'-hydroxyacetophenone Derivatives As The First Ligands

Two series (a total of 10 compounds) of 2'-hydroxyacetophenone derivatives as first ligands (L1n, L2n) and diazaspirobifluorene ligand (SBF) with rigid backbone and good charge carriers transporting ability were synthesized in this paper. With 2'-hydroxyacetophenone derivatives (Ln) as the first ligands 1,10-phenanthroline and diazaspirobifluorene ligand as the secondary ligand separately coordination with rare earth Eu3+, two series of novel ternary europium(Ⅲ) complexes were synthesized. Those complexes were characterized by elemental analysis (EA), UV-Vis spectra and photoluminescent properties such as solid state luminescent intensity, photoluminesence quantum yield and lifetime et al. The results showed that:1.All the solid state complexes exhibit intense red emissions typical of Eu3+ ion at room temperature under the long-wavelength excitation of 350-470nm, the maximum photo-luminescent quantum yield was 25.8%. The ligand(Ln) to Eu3+ charge transfer (LMCT) absorption is said to be the contributing factor for Eu3+ sensitized emissions. The europium complexes with 1,10-phenanthroline as the second ligand show much better luminescent efficiency in comparison with SBF as the second ligand. However, the good electron transport property still makes diazaspirobifluorene ligand a potential electroluminescence material.2.Using Eu(L16)3SBF as the emitting material, A three-layered device, ITO/TPD(30 nm)/BCP(10nm)/Eu(L16)3SBF:CBP(15%)(20nm)/AlQ3(30nm)/LiF:Al, was fabricated.OLED used Eu(L16)3SBF as dopant gave the maximum pure red luminance of 686 cd/m2 at 14 V and 185 mA/cm2 and a turn-on voltage of 4V. It can be concluded that the ternary europium complex possesses excellent electron-transporting ability, and the 2'-hydroxyacetophenone -type ligand plays an important role in improving the electron-transporting abilities of the complex. It can be concluded that the ternary europium complex possesses excellent electron-transporting ability, and the 2'-hydroxyacetophenone-type ligand and diazaspirobifluorene ligand play an important role in improving the electron-transporting abilities of the complex.Furthermore, a series of novel 2'-hydroxyacetophenone aluminum complexes were synthesized and characterized by elemental analysis (EA), UV-Vis spectra and luminescent properties. Those complexes show excellent green photoluminescent properties with luminescent intensities comparable with the famous green electroluminescent material of tris-(8-hydroxyquinoline), which make those complexes good candidates as electroluminescent materials. Due to different substituents, the emission peak of these aluminum complexes has some displacement compared wit. It can be known from spectroscopic data that:they both have high luminescent intensity and solid-state luminous efficiency, and are very likely to become electron transport materials with high performance.