[en] A simple flow injection chemiluminescence (CL) analysis method for the determination of europium in mineral samples is reported. It is based on luminescence produced by NaIO₄-H₂O₂ CL system sensitized by [Eu(EDTA)]^-. The relative chemiluminescence intensity of the Eu³⁺-EDTA-NaIO₄-H₂O₂ system is proportional to the amount of Eu³⁺. The optimized experimental conditions were investigated. The linear range and detection limit for Eu³⁺ are 2.0x10^-7 to 1.0x10^-5 and 6.2x10^-8 M, respectively. The sample throughput of the method is 80 samples/h. This method was successfully applied to the determination of europium in rare earth oxides. And the mechanism of chemiluminescence is proposed

[en] Stable vacuum deposition of a new europium(III) complex, Eu(DBM)₃(L) {DBM=dibenzoylmethanato, L=3-ethyl-2-(4'-dimethylaminophenyl)imidazo[4,5-f]1,10-phenanthroline}, were verified by ultraviolet-visible and infrared spectroscopy. By using the vacuum deposited film of the Eu(III) complex as the emitting layer, aluminum tris(8-hydroxyquinolinate) (AlQ) as electron-transporting layer, 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP) as hole-blocking layer, N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-diphenyl-4,4'-diamine (TPD) as hole-transporting layer, a four-layer electroluminescent device of (+)indium-tin oxide/TPD(40 nm)/Eu(DBM)₃(L)(40 nm)/BCP(10 nm)/AlQ(40 nm)/Mg:Ag(110 nm)/Ag(60 nm)(-) gave high efficient and pure red light emission with a luminance of 230 cd/m². A comparison of the electroluminescence properties of the four-layer device with those of a two-layer and a three-layer device was made

[en] In order to develop new materials for red electroluminescent devices, a novel ligand, 2-phenyl-imidazo[4,5-f]1,10-phenanthroline (L), and an europium (III) complex with dibenzoylmethanate (DBM), Eu(DBM)₃L, was synthesized. The crystal structure of Eu(DBM)₃L was determined by single crystal X-ray diffraction. The crystal of Eu(DBM)₃L belongs to orthorhombic, space group Pbca with cell dimensions of a=2.1655(6) nm, b=2.0834(5) nm, c=2.6469(7) nm, V=11.942(5) nm³, Z=8, D_x=1.307 g/cm³. Each europium atom is coordinated with six oxygen atoms from three bidentate DBM anions and two nitrogen atoms from one bidentate L, forming a distorted square antiprism. The complex is easily evaporated and can be used as a red light emitting material. Upon improvement, the device with a structure of ITO/N,N'-diphenyl-N,N'-bis(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine (TPD) (40 nm)/Eu(DBM)₃L (50 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine or BCP) (20 nm)/tris(8-hydroxyquinoline) aluminum (ALQ) (30 nm)/cathode gives off pure red light with luminance of 42 cd/m² at 16 V

[en] This paper described Ln 3d_5/2 photoelectron spectra and satellite phenomena for lanthanide complexes of benzo-15-crown-5 and dibenzo-18-crown-6. Changes in electronic structure and covalency for the complexes were discussed. Regular variation between Ln 3d_5/2 binding energy and 1/γ appears

[en] This paper firstly reports the second-order scattering (SOS) phenomenon in the nucleic acid system using a common spectrofluorometer. And a novel determination method of nucleic acids at nanogram level has been developed. Studies involving calf thymus DNA (ctDNA), fish sperm DNA (fsDNA) and yeast RNA (yRNA) showed that the SOS intensity of nucleic acids can be enhanced by La³⁺, Ce³⁺, Nd³⁺, Sm³⁺, Eu³⁺, Gd³⁺ and Tb³⁺ ion, of which Eu³⁺ ion has the largest enhancement. And the intensity of the SOS is proportional to the concentration of nucleic acids. Maximum SOS peak at 550 nm appeared at pH 7.5 and 6.0 x 10^-5 mol l^-1 CTMAB (cetyltrimethylammonium bromide). Under the optimal conditions, the calibration graphs were linear in the range of 1.0 x 10^-8 to 4.0 x 10^-5 g ml^-1 for ctDNA, 6.0 x 10^-9 to 2.0 x 10^-6 g ml^-1 for fsDNA, and 8.0 x 10^-9 to 1.0 x 10^-6 g ml^-1 for yRNA, respectively. The detection limits were 1.7 ng ml^-1 for ctDNA, 0.36 ng ml^-1 for fsDNA and 0.21 ng ml^-1 for yRNA, respectively. In comparison with most other methods for the determination of nucleic acids, this method is more convenient, more sensitive and simpler. And the possible mechanism was proposed