Guiling Ning

Sol-gel processed Ce3+, Tb3+ codoped white emitting phosphors in Sr2Al2SiO7

Abstract Sr 2 Al 2 SiO 7 :Ce 3+ , Tb 3+ white emitting phosphors were fabricated using the sol-gel method. X-Ray Powder Diffraction (XRD) analysis confirmed the formation of Sr 2 Al 2 SiO 7 :Ce 3+ , Tb 3+ . Scanning Electron Microscopy (SEM) observation indicated that the microstructure of the phosphor consisted of regular fine grains with an average size of about 0.5–1 μm. Luminescence properties were analyzed by measuring the photoluminescence spectra. The Ce 3+ , Tb 3+ -codoped Sr 2 Al 2 SiO 7 phosphors showed four main emission peaks: one at 414 nm for Ce 3+ and three at 482, 543, and 588 nm for Tb 3+ . The emission spectra of the samples with different doping concentrations showed that the Tb 3+ emission was dominant because of the persistent energy transfer from Ce 3+ . The decay characteristic was better than that prepared by the solid-state process in the comparable condition. The codoped phosphor displayed long persistent white phosphorescence.

A new two-dimensional cadmium metal-organic framework: poly[bis(4,7-diphenyl-1,10-phenanthroline)(μ3-5-nitroisophthalato)cadmium(II)].

In the title cadmium metal-organic framework complex, [Cd(C(8)H(3)NO(6))(C(24)H(16)N(2))](n) or [Cd(NIPH)(dpphen)] (NIPH is nitroisophthalate and dpphen is 4,7-diphenyl-1,10-phenanthroline), the unique Cd(II) cation in a general position is coordinated by four carboxy O atoms from three symmetry-related NIPH anions and two N atoms from a dpphen ligand. The Cd(II) cations are bridged by pairs of NIPH anions to generate a dinuclear molecular building block, [Cd(2)N(4)(CO(2)R)(4)], with a Cd···Cd separation of 4.0936 (10) Å. Each such building block is connected to four adjacent dinuclear building blocks by NIPH anions, resulting in a two-dimensional layer framework in the bc plane. The dpphen ligands occupy the space between these layers and are linked by π-π interactions, with a separation of 3.4541 (6) Å between the central aromatic rings of inversion-related dpphen ligands. The thermogravimetric and photoluminescent properties of the complex have also been investigated.

(μ-2,11-Dithia­[3.3]paracyclo­phane-κ2S:S′)bis­[(6-carboxy­pyridine-2-carboxylato-κ2N,O6)silver(I)]: a mixed-ligand silver-based dinuclear compound

In the title complex, [Ag2(C7H4NO4)2(C16H16S2)], each Ag(I) atom is trigonally coordinated by one S atom of a 2,11-dithia[3.3]paracyclophane (dtpcp) ligand, and by one N and one O atom of a 6-carboxypyridine-2-carboxylate ligand. Dtpcp acts as a bidentate ligand, bridging two inversion-related AgI atoms to give a dinuclear silver(I) compound. The dinuclear moieties are interconnected via O-H...O hydrogen bonds to form a two-dimensional zigzag sheet. Two such sheets are interwoven via pi-pi interactions between pyridine rings, affording an interwoven bilayer network.