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A new metal-organic complex Zn2(cbba)4(phen)2 (Hcbba = 2-(4'chlorine-ben- zoyl)benzoic acid, phen = 1,10-phenanthroline) 1 has been hydrothermally synthesized and structurally characterized by elementa... 相似文献
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A new metal-organic complex [Mn2(PDC)2(bipy)2(H2O)2] (H2PDC = 2,4-pyridine-dicarboxylic acid, bipy = 2,2′-bipyridine) 1 has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectrum, TG and single-crystal X-ray diffraction. The compound crystallizes in triclinic, space group P ^-1 with a = 7.376(3), b = 9.990(4), c = 11.950(5) A^°, α= 75.217(5), β = 78.052(5), γ = 70.655(5)°, V = 796.0(5)A^°3, C34HE6Mn2N6O10, Mr = 788.49, De = 1.645 g/cm^3,μ(MoKa) = 0.866 mm^-1, F(000) = 235, Z = 1, the final R = 0.0425 and wR = 0.0700 for 1971 observed reflections (I 〉 2σ(I)). In the crystal structure, the manganese atom is six-coordinated by two carboxylate oxygen atoms from two different PDC ligands, one aqua ligand, and three nitrogen atoms from 2,2′-bipy and PDC ligands, giving a distorted octahedral geometry. It exhibits a three-dimensional supramolecular network defined by O-H…O hydrogen-bonding interactions. 相似文献
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Non-negative matrix factorization (NMF), with the constraints of non-negativity, has been recently proposed for multi-variate data analysis. Because it allows only additive, not subtractive, combinations of the original data, NMF is capable of producing region or parts-based representation of objects. It has been used for image analysis and text processing. Unlike PCA, the resolutions of NMF are non-negative and can be easily interpreted and understood directly. Due to multiple solutions, the original algorithm of NMF [D.D. Lee, H.S. Seung, Nature 401 (1999) 788] is not suitable for resolving chemical mixed signals. In reality, NMF has never been applied to resolving chemical mixed signals. It must be modified according to the characteristics of the chemical signals, such as smoothness of spectra, unimodality of chromatograms, sparseness of mass spectra, etc. We have used the modified NMF algorithm to narrow the feasible solution region for resolving chemical signals, and found that it could produce reasonable and acceptable results for certain experimental errors, especially for overlapping chromatograms and sparse mass spectra. Simulated two-dimensional (2-D) data and real GUJINGGONG alcohol liquor GC-MS data have been resolved soundly by NMF technique. Butyl caproate and its isomeric compound (butyric acid, hexyl ester) have been identified from the overlapping spectra. The result of NMF is preferable to that of Heuristic evolving latent projections (HELP). It shows that NMF is a promising chemometric resolution method for complex samples. 相似文献
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This paper describes a facile sy]nthetic method for preparing monodisperse silver nanoparticles by bio-template of the squama
inner coat of onion. The method is able to make silver nanoparticles with average diameters in the range of 4.6–7.9 nm with
narrow size distribution. The important factors in the synthesis of monodisperse silver nanoparticles were discussed. The
nanoparticles were characterized by transmission electron microscope, Powder X-ray diffraction and UV-Vis spectroscopy. A
possible formation mechanism was also proposed. Because of its simple apparatus, high yield, convenient operation and mild
conditions, this synthetic method will have potential application in preparing nanoparticles. 相似文献
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A metal-organic coordination polymer [Cd2(PDC)2(bix)(H2O)2]n ·nH2O(H2PDC=2,4-pyridinedicarboxylic acid, bix=1,4-bis(imidazol-1-ylmethyl)-benzene) 1 has been hydrothermally synthesized and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Brown crystals crystallize in the orthorhombic system, space group P2 12 12 1 with a=11.741(3), b=14.190(4), c=18.963(5) , V=3159.4(14) 3 , C28H26Cd2N6O11, Mr=847.35, Dc=1.781 g/cm3 , F(000)=1680, Z=4, μ(MoKα)=1.415 mm 1 , the final R=0.0381 and wR=0.0882 for 5472 observed reflections (I >2σ(I)). The structure of 1 exhibits a threedimensional network structure. 相似文献
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A metal-organic coordination polymer [Cd(PDB)(bimb)]n (H2PDB=3,4-pyridine- dicarboxylic acid, bimb=1,4-bis(imidazol-1-ylmethyl)-butane) 1 has been hydrothermally synthesi- zed and characterized by elemental analysis, IR, TG, fluorescence spectrum and single-crystal X-ray diffraction. Yellow crystals crystallize in the monoclinic system, space group Cc with a=19.001(5), b=7.948(2), c=13.392(4) , β=120.803(3)o, V=1737.0(8)3, C17H17CdN5O4, Mr=467.76, Dc=1.789 g/cm3, F(000)=936, Z=4, μ(MoKα)=1.293 mm-1, the final R=0.0266 and wR=0.0534 for 2707 observed reflections (I > 2?(I)). The structure of 1 exhibits a three-dimensional network structure. 相似文献
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A new metal-organic complex Pb(cbba)2(phen)2 (1, H2cbba=2-(4′-chlorine-benzoyl)benzoic acid, phen= 1,10-phenanthroline) has been hydrothermally synthesized and structurally characterized by elemental analysis, IR, fluorescence spectrum and single-crystal X-ray diffraction. The compound crystallizes in orthorhombic, space group Pbcn with a=1.474 49(7) nm, b=0.953 90(4) nm, c=3.031 65(14) nm, V=4.264 1(3) nm3, C52H32Cl2N4O6Pb, Mr=1 086.91, Dc=1.693 g·cm-3, μ(Mo Kα)=4.141 mm-1, F(000)=2 144, Z=4, the final R=0.018 3 and wR=0.045 7 for 3 582 observed reflections (I2σ(I)). In the crystal structure, the lead atom is six-coordinated with two carboxylate oxygen atoms from different cbba ligands and four nitrogen atoms from different phen ligands, showing a distorted octahedral geometry. Furthermore, 1 shows yellow photoluminescent property at room temperature. 相似文献
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<正>0 Introduction The rational design and synthesis of metal-directed supramolecular frameworks have received much attention in coordination chemistry because of their interesting molecular topologies and tremendous potential applications in host-guest chemistry 相似文献
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A new organometallic coordinate polymer {[Zn2(4-sphth)2(4,4'-bpy)4(H2O)4][Zn(4,4'-bpy)2(H2O)4]}n·n[(4,4'-bpy)(H2O)4](4-sphth=4-sulfophthalic acid,4,4'-bpy = 4,4'-bipyridine) 1 has been hydrothermally synthesized and characterized by elemental analysis,IR,fluorescence spectrum and single-crystal X-ray diffraction.The complex crystallizes in monoclinic,space group C2/c with a=18.8659(13),b=23.0861(13),c=22.5449(14),β=107.4120(10)o,V=9369.3(10)3,Mr=1981.86,Dc=1.405 g/cm3,μ(MoKα)=0.891 mm-1,F(000)=4100,Z=4,the final R=0.0644 and wR=0.1615 for 5984 observed reflections(I 2σ(I)).Furthermore,compound 1 shows blue photoluminescent property at room temperature. 相似文献