The hyperfine red phosphors,NaEu(MoO4)2,were synthesized by hydrothermal and subsequent heat-treatment processes.The NaEu(MoO4)2 phosphors show regular elliptical morphologies,and the particle sizes of 0.25～0.3 μm.The excitation spectra located at short-wavelength UV region belong to the interweave broad charge transfer bands of Mo6+-O2-and Eu3+-O2-,and the three sharp lines around 395 nm,465 nm and 535 nm are ascribed to the Eu3+ 4f excitation transitions.All of the samples can be excited with near-UV 395 nm light and exhibit the characteristic red emission of Eu3+ 5D0→7F2transition.The relative red emission intensities of the optimum phosphors reach two-fold as compared with that of the commercial phosphors.The submicro-phosphors may be applied as red phosphors for white light emitting diodes.
A metal-organic coordination polymer {[La(PDC)(N-HPDC)].H2O}n (1) (H2PDC=pyridine-3,4-dicarboxylic acid) has been hydrothermally synthesized and structurally characterized by X-ray diffraction single-crystal structure determination,elemental analyses and IR spectroscopy. The complex crystallizes in the monoclinic system,space group P21/c with a=1.452 8(2) nm,b=0.681 59(11) nm,c=1.464 0(2) nm,β=94.270(2)°,V=1.445 6(4) nm3,Dc=2.243 Mg.m-3,Z=4,Mr=488.14,F (000)=944,μ (Mo Kα)=3.015 mm-1,R=0.031 0 and wR=0.076 2 for 2 424 observed reflections (I>2σ(I)). There are La-O-C-O-C-La double chains in the complex. The chelating carboxylate O atoms and pyridyl N atoms lead the compound to 2D layers structure,which is extended to 3D supramolecular architecture through intermolecular hydrogen bonds. It is interesting that the polymer containing one-dimensional channels. CCDC:708868.
A one-dimensional complex,[Gd2(PDC)3(phen)(H2O)·H2O]n(H2PDC=pyridine-3,4-dicarboxylic acid,phen =1,10-phenanthroline),has been synthesized under hydrothermal conditions and characterized by elemental analysis,IR,TG analysis,and X-ray single-crystal structure analysis.Crystallographic data for the title complex: C33H21Gd2N5O14,Mr=1 026.05,Triclinic,space group P,a=0.751 07(15) nm,b=1.256 5(3) nm,c=1.825 7(4) nm,α= 70.80(3)°,β=79.00(3)°,γ=76.05(3)°,V=1.567 4(5) nm3,the final refinement gave R=0.022 4 and wR=0.047 5 for 4 913 observed reflections with I>2σ(I).The coordination polymer displays a 1D belt-like chain.The 1D chain connected with adjacent chains through π-π stacking interaction of phen groups to form 2D layers,which are further extended to a 3D supramolecular network through H-bonds interaction.CCDC: 671430.
