We develop high efficiency solution-processed pure green organic light-emitting devices using a starburst molecule 7,7′,7″-(5,5,10,10,15,15-hexahexyl-10,15-dihydro-5H-diindeno[1,2-a:1′,2′-c]fluorene-2,7,12-triyl)tris(4-(4-(9H-carbazol-9-yl)phenyl)benzo[c][1,2,5]thiadiazole)(TRcz)doped 2-methyl-9,10-di(2-naphthyl)anthracene(MADN)as the emitting layers.The electroluminescence properties of the devices with different doping concentrations are investigated.With the increasing doping concentration from 0.5wt%to 5wt%,the maximum efficiency changes from 4.8cd/A to 8.4cd/A.Under the optimal concentration of 4wt%,the device shows pure green emission at 516nm with a chromaticity coordinate of(0.30,0.59)as well as a high brightness of 19900cd/m^(2)and a high efficiency of 10.1cd/A,which are better than 11490cd/m^(2)and 4.2cd/A obtained in the undoped device.
Three isostructural three-dimensional(3D) lanthanide-based metal-organic frameworks [Ln_2L(H_2L)(NMP)_2].H_2O(Ln=Sm(1), Eu(2), Gd(3); H_4L=1,1′:4′,1″-terphenyl-2′,4,4″,5′-tetracarboxylic acid; NMP=N-methyl-2-pyrrolidone) have been synthesized and structurally characterized. In 1–3, two Ln3+ ions are doubly-bridged by two oxygen atoms of two carboxylate groups to form the dinuclear Ln_2(OCOO–)_2 unit. Each Ln_2(OCOO–)_2 unit links with four H_2L^(2-) ligands and four L4. ligands to lead to the 3D framework,which can be rationalized as a new trinodal 4,4,8-connected(44.62)(45.6)(412.616) topological network by considering the dinuclear Ln_2(OCOO–)_2 units as 8-connected nodes and L^4./H_2L^(2-) ligands as planar 4-connected nodes, respectively. 1 and 3 exhibit blue emission originated from the ligand with the emission maximum at 384 nm, while 2 shows intense characteristic red emission of Eu^(3+) ions and weak ligand-centered emission. Moreover, 2 has fluorescent quenching response towards the aromatic nitro compounds, especially for the 3,4-dinitrotoluene(3,4-DNT) with the linear Stern-Volmer relationship in the concentration range of 0–1 mM and the quenching constant(Ksv) of 2.084×10~3 M^(-1).
Cupric oxide(CuO)nanoparticles were grown on zinc oxide(ZnO)nanorod(NR)arrays to form ZnO–CuO corn-like composites via a simple two step solution-based method.First,ZnO nanorods were grown on a glass substrate by the hydrothermal method.Afterwards,CuO crystals were photochemically deposited on ZnO NRs using ultraviolet(UV)light irradiation at room temperature.The density and size of CuO nanoparticles(NPs)on ZnO NRs can be controlled by the irradiation time of UV light.The structural and optical properties of ZnO–CuO nanocomposites were characterized by using various techniques such as UV-vis absorption spectroscopy,photoluminescence,scanning electron microscopy,energy dispersive x-ray spectroscopy,and x-ray diffraction.ZnO–CuO nanocomposites show an excellent improvement in photocatalytic characteristics compared to bare ZnO NRs.
A new star-shaped oligoelectrolyte (TEFCOONa) with triphenylamine as the core, acetylene as linkage and anionic fluorenes as arms was obtained and used for direct imaging in living PANC-1 cells. Because of the hydrophobic conjugated groups of the oli-goelectrolyte, TEFCOONa can form nanospheres with an average diameter of^75 nm in 10 mmol/L PBS. These nanospheres possess a relatively high absolute quantum yield (16.5% in PBS), low cytotoxicity and can penetrate into the nucleus through the cytoplasm, which is essential for living cellular imaging. Collectively, these results validate our rational design of conjugated oligoelectrolyte and even hyper branched polymers-copolyelectrolyte as effective nanovectors for bioimaging and other clinical applications.
SONG WenLiJIANG RongCuiYUAN YanLU XiaoMeiHU WenBoFAN QuLiHUANG Wei
