Studies On The Synthesis, Structure And Luminescence Properties Of Novel Eu(â…¢) Complexes

In order to obtain the excellent photo and electro-luminescent lanthanide complexes, Two series of new Eu(III) complexes with azatriphenylenes as the second ligand and imide as the first ligand were prepared in this parper. The structure characters and PL properties of these complexes were fully described. The three-layer EL diodes were prepared using Eu(DBM)3L as emitting material, their EL properties were described briefly.1. Five azatriphenylenes ligands: dipyrido [2,3-a:2',3'-c] quinoxaline(dpq) 7-methyl-dipyrido[2,3-a:2',3'-c]quinoxaline(dpmq) dipyrido[2,3-a:2',3'-c]phenazine(dppz) 8-methyl-dipyrido[2,3-a:2',3'-c]phenazine(dpmp) and dipyrido[2,3-a:2',3'-c] -7,8,9,10-tetraphenazine(dptp) were synthesized. Using these azatriphenylenes as the second ligands, DBM (dibenzoylmethane) and TTA (2-Thenoyltrifluoroacetone) as the first ligands ten new ternary Eu(IH) complexes were synthesized. The crystal analysis results of Eu(DBM)3 dpq, Eu(DBM)3 dppz and Eu(TTA)3 dpq indicated that Eu(III) ion is eight coordinated with six oxygen atoms from three first ligands and two nitrogen atoms from netural ligand, forming a distorted square antiprism. There are strong π-π stacking interaction between the adjacent complex molecules. Under UV excitation, all these complexes exhibit bright typical emission of Eu(III) ion, with the emission intensity decrease in the order: Eu(DBM)3 dpq > Eu(DBM)3dpmq > Eu(DBM)3dptp > Eu(DBM)3dppz > Eu(DBM)3dpmp; Eu(TTA)3dptp >Eu(TTA)3dpmq > Eu(TTA)3dppz > Eu(TTA)3dpq > Eu(TTA)3dpmp.2. Five new imide ligands: 4-Methyl-N-(5-phenyl-[l,3,4]oxadiazol-l-yl)-benzamide(L1) 4-Methoxy-N-(5-phenyl-[1,3,4]oxadiazol-1-yl)- benzamide(L2) N-(5-phenyl-[1,3,4]oxadiazol-l-yl)- nicotinamide N-(5-phenyl-[1,3,4]oxadiazol-1-yl)-isonicotinamide and Naphthalene-1-caroxylic acid(5-phenyl-[1,3,4]oxadiazol-2-yl)-amide were synthesized. Using these imides as first ligand and 1,10-phenanthroline as second ligand five new ternary Eu(III) complexes were prepared. The crystal analysisresults of Eu(L(2)3phen and Eu(L3)3phen indicated that imide Iigands coordinates with Eu(III) ion through the oxygen atom of the carbonyl group in the enol form, and the nitrogen atom of the oxadizol group. The coordinate polyhedron of Eu(III) ion is a distorted square antiprism. All these complexes exhibit typical emission of Eu(III) ion and the PL intensity vary with different aryl in first Iigands with the sequence Eu(L4)3Phen > Eu(L3)3Phen > Eu(L5)3Phen > Eu(L2)3Phen > Eu(Li)3Phen.3. Using Eu(DBM)3L (L=azatriphenylene) as emitting materials five three-layer EL devices with the configuration of ITO/TPD (30 nm)/ europium complex :TPD(1:2) (50 nm)/Gd(DBM)3bath(30 nm)/Mg:Ag were prepared. The devices with Eu(DBM)3dpq Eu(DBM)3dpmq and Eu(DBM)3dptp as emitting material exhibit the characteristic emission of Eu(III) ion, the maximum EL brightness are 304 cd/m2 112.2 cd/m2 and 122.4 cd/m2 respectly; Devices with Eu(DBM)3dppz and Eu(DBM)adpmp as emitting material show a wide emission band aside from the Eu(III) ion emission, the maximum EL brightness are 280 cd/m2 and 312 cd/m2 respectly.