Synthesis, Crystal Structure and Luminescence of a New Europium(Ⅲ) Coordination Polymer with Imidazole Carboxylic Ligand

A new luminescent compound,{[Eu3(L)4(H2O)8]·(NO3)·4H2O}n(1,H2L=2-(pyridine-3-yl)-imidazole-4,5-dicarboxylic acid)has been solvothermally synthesized and structurally characterized by elemental analyses,IR and single-crystal X-ray diffraction.1 crystallizes in monoclinic,space group C2/c with a=21.0183(19),b=9.5227(6),c=28.227(3)A,β=106.885(5)°,V=5406.1(8)A3,Dc=2.038 g/cm3,μ=3.358 mm1,Mr=1658.76,F(000)=3247,Z=4,the final R=0.0488,wR=0.1195 and S=1.075.The deprotonated L ligand employs aμ4-bridge to coordinate with three Eu(Ⅲ)ion,forming a wave-like(3,4)-connected 2D structure.The existence of π…πinteraction between the pyridine rings of L ligands leads to an infinite 3D network.Furthermore,the thermal analysis,powder diffraction and solid-state photoluminescent properties of compound 1 have also been investigated.

(2D+1D)Hydrogen Bond Structure Constructed from Dendrimer Precursor

The title compound, CsH12NO4＂2（H20） 1, was obtained by slow diffusion of cop- per sulfate solution into the solution of 1,4-N,N-bis[tri（hydroxy）methyl]terephthaldiamide in DMSO and characterized by elemental analysis and infrared spectra. The crystal of 1 crystallizes in the monoclinic space group P2Jc with a = 12.943（7）, b = 6.446（3）, c = 14.157（5） A, fl = 119.76（3）, V = 1025.4（9）/3, Z = 2, C16H32N2OI2, Mr= 444.44, Dc= 1.439 g/cm3, F（000） = 476 and/（MoKa） = 0.123 mm＂1. The final R = 0.0484 and wR = 0.1080 for 1776 observed reflections with 1〉 2r（/） and R = 0.0679 and wR = 0.1183 for all data. X-ray diffraction reveals that the （2D＋ID） hydrogen bonds pillar the structure into an open 3D supramolecular framework with a pore along the b axis （approximate dimensions 5.9＊10.5 /2）, which is occupied by free water molecules. Photolu- minescent investigation reveals that the title compound displays an emission in the blue region.

Potassium-decorated active carbon supported Co-Mo-based catalyst for water-gas shift reaction

The effect of potassium-decoration was studied on the activity of water-gas shift （WGS） reaction over the Co-Mo-based catalysts supported on active carbon （AC）, which was prepared by incipient wetness co-impregnation method. The decoration of potassium on active carbon in advance enhances the activities of the CoMo-K/AC catalysts for WGS reaction. Highest activity （about 92% conversion） was obtained at 250 ？ C for the catalyst with an optimum K 2 O/AC weight ratio in the range from 0.12 to 0.15. The catalysts were characterized by TPR and EPR, and the results show that activated carbon decorated with potassium makes Co-Mo species highly dispersed, and thus easily reduced and sulfurized. XRD results show that an appropriate content of potassium-decoration on active carbon supports may favors the formation of highly dispersed Co 9 S 8 -type structures which are situated on the edge or a site in contact with MoS 2 , K-Mo-O-S, Mo-S-K phase. Those active species are responsible for the high activity of CoMo-K/AC catalysts.

Assembly of a Heteronuclear POM {[K_5Na_6Cu_5(Ⅱ)(CH3COO)_(20)(CH_3CN)]Cl}_n via Two Kinds of Clusters as the Basic Bridge Unit

A novel 3D hetero-nuclear framework,namely {[K_5Na_6Cu_5^（Ⅱ）（CH3COO）_（20）（CH_3CN）]Cl}_n（1）,was obtained by hydrothermal reaction.Triple metal centers（including sodium/potassium or/and copper） were coordinated to acetate anions in such two heteronuclear clusters,respectively.Moreover,nine kinds of binding modes for acetate anions were illustrated in polymer 1,with the first reported pentadentate coordination mode for acetate ligand.

Shared Sets and Normal Families

This paper deals with the problem of normal families concerning share sets. Moreover, the examples show that the conditions of theorem are necessary.