192 resultados para CaZn2(OH)(6)center dot 2H(2)O
Resumo:
The title mixed-metal complex, {(NH4)(2)[Cu(C7H3NO4)(2)(H2O)(2)][CdCu(C7H3NO4)(2)(H2O)(6)]center dot 6H(2)O}(n), contains one octahedrally coordinated Cd-II center and two octahedrally coordinated Cu-II centers, each lying on an inversion center. The two Cu-II atoms are each coordinated by two O atoms and two N atoms from two 2,4-pydc (2,4-H(2)pydc = pyridine-2,4-dicarboxylic acid) ligands in the equatorial plane and two water molecules at the axial sites, thus producing two crystallographically independent [Cu(2,4-pydc)(2)(H2O)(2)](2-) metalloligands. One metalloligand exists as a discrete anion and the other connects the Cd(H2O)(4) units, forming a neutral chain.
Resumo:
In this paper, four novel silver(I) sulfonate coordination polymers containing neutral ligands, namely, [Ag(2)Ll (biim)(2)]center dot 2H(2)O (1). AgL2(biim) (2), [Ag(HL3)(Pic)(2)]center dot H2O (3), and [Ag-3(L3)(HL3)(4,4'-bipy)(3)(H2O)(2)]center dot 4H(2)O (4), have been synthesized [L1 = 3-carboxy-4-hydroxybenzenesulfonate, L2 = p-aminobenzenesulfonate, H(2)L3 = p-hydroxybenzenesulfonic acid, biim = 1,1'-(1.4-butanediyl)-bis(imidazole), Pic = beta-picoline, 4,4'-bipy = 4,4'-bipyridine]. For compounds 1 and 2, Ag(I) cations are bridged by biim ligands to form a one-dimensional (1D) "zigzag" chain, and L1 and L2 sulfonate ligands are not coordinated to the silver cation. Compound 3 has a dimeric structure in which two silver cations are bridged by two HL3 ligands. For compound 4, L3 ligand coordinates to a silver cation as a monodentate ligand, and Ag(l) cations are bridged by 4,4'-bipy ligands to form a ID chain. Compound 1 contains water dimers, while compound 4 contains water trimers. Compounds 1-3 display room-temperature photoluminescence.
Resumo:
Two new Cull coordination polymers, namely [Cu-2(BDC)(2)(L)(4)(H2O)(2)]center dot 14H(2)O (1) and [Cu-1.5(BTC)(L)(1.5)(H2O)(0.5)]center dot 2H(2)O (2), where L = 1,1'-(1,4-butanediyl)bis(imidazole), BDC = 1,4-benzene dicarboxylate, and BTC = 1,3,5-benzenetricarboxylate, have been synthesized at room temperature. Complex 1 exhibits an unusual, square-planar, four-connected 2D (2)(6)4 net, which has been predicated by Wells. Interestingly, three types of water clusters, namely (H2O)(6), (H2O)(8), and (H2O)(10), are observed in the hydrogen-bonded layers constructed by the BDC ligands and water molecules. The BTC anion in compound 2 is coordinated to the Cu" cation as tetradentate ligand to form a (6(6))(2)(4(2)6(4)8(4))(2)(6(4)810) net containing three kinds of nonequivalent points, Thermogravimetric analyses (TGA) and IR spectra for 1 and 2 are also discussed in detail.
Resumo:
In the title structure, [Cu(C12H8N2)(H2O)(4)](C10H6S2O6)center dot-2H(2)O, the cation lies on a crystallographic twofold rotation axis and the anion lies on a centre of inversion. The Cu-II atom is coordinated by two N atoms of a 1,10-phenanthroline ligand and four O atoms from four water ligands in a distorted octahedral geometry. The unique Cu-O distances are 2.054 (2) and 2.088 (2) angstrom and the Cu-N distance is 2.073 (2) angstrom. In the crystal structure, a three-dimensional supramolecular framework is constructed by extensive intermolecular O-H center dot center dot center dot O hydrogen bonds.
Resumo:
Nanopowder of Y(1.84)mLa(0.16)O(3) was prepared by oxalate co-precipitation method. The powder was characterized by TG-DTA, XRD and TEM. The results show that the precursor is Re-2 (NO3)(2) (C2O4)(2)center dot 2H(2)O (Re=Y, La), and the Y1.84La0.16O3 nanopowders produced by calcining the precursor at 1000 degrees C for 4 h are 20 similar to 40 nm spherical particles and well dispersed. The powders were with high sintering activity and could be fabricated to transparent ceramic without additive at 1450 similar to 1550 degrees C in H-2 atmosphere for 3 hours. The total transmission of the transparent ceramic could reach 80%.
Resumo:
The novel nanoparticles, [Ru(bPY)(3)](2)SiW12O40 center dot 2H(2)O(2) were firstly synthesized and characterized by elemental analysis, IR, and TEM. The nanoparticles were used to fabricate a chemically modified carbon paste electrode (CPE) by dispersing nanoparticles and graphite powder in silicone grease. Thus-prepared CPE shows bifunctional electrocatalytic activities towards the reduction of nitrite and the oxidation of oxalate, and exhibits sensitive electrochemiluminescence (ECL).
Resumo:
A urea-based bis-silylated bipyridine ligand derived from 4,4'-diamino-2,2'-bipyridine has been prepared. Organic-inorganic hybrid materials with a high loading of lanthanide 2,2-bipyridine moieties were obtained by using the silylated bipyridine as the only siloxane network precursor in the presence of lanthanide ions (or lanthanide complexes). The in-situ formation of lanthanide complexes from lanthanide ions and the silylated bipyridine during the sol-gel processing was confirmed by the luminescence behavior of the obtained hybrid materials and that of the corresponding pure lanthanide complex [Ln(bpy)(2)Cl-3 center dot 2H(2)O].
Resumo:
The electrochemical properties of a series of structurally related fullerooxazoles, [6,6] cyclic phenylimidate C-60 (1), 1,2-benzal-3-N-4-O-cyclic phenylimidate C-60 (2), and 1,4-dibenzyl-2,3-cyclic phenylimidate C-60 (3), are described, and the spectroscopic characterizations of their anionic species are reported. The results show that compounds I and 2 undergo retro-cycloaddition reactions that lead to the formation of C-60 and C61HPh, respectively, upon two-electron-transfer reduction. However, compound 3 demonstrates much more electrochemical stability as no retro-cycloaddition reaction occurs under similar conditions. Natural bond orbital (NBO) calculations on charge distribution show there is no significant difference among the dianions of 1, 2, and 3, indicating that the electrochemical stability of 3 is unlikely to be caused by the charge distribution difference of the dianions of three compounds. Examination on the crystal structure of compound 3 reveals close contacts of the C-H group with the heteroatoms (N and O) of cyclic phenylimidate, suggesting the existence of C-H center dot center dot center dot X (X = N, O) intramolecular hydrogen bonding among the addends, which is further confirmed by NBO analysis.
Resumo:
(2,4-C7H11)(2)Yb . DME was synthesized by the reaction of YbCl3 with K(2,4-C7H11)(2,4-dimethylpentadienyl potassium), and the single crystal X-ray diffraction showed that the complex exists in a cis- staggered conformation. Thf crystal of the compound belongs to the monoclinic space group P2(1)/n with a = 0.675 2 (1) nm, b = 1.490 6 (1) nm, c = 1.529 3 (2) nm, beta = 97.55 (2)degrees, V = 1.977 79 (4) nm(3), Z = 4, F(000) = 735.8 e, mu = 49.49 cm(-1), R = 0.033 and R-w = 0.032. The title complex can be used as a catalyst for the polymerization of methyl methacrylate (MMA).
Resumo:
[La(NO3)(3)(OH2)(2)(phen)]. 15-crown-5 is hexagonal, P6(5), with a = 10.955(2), c = 43.769(9) Angstrom, and D-calc = 1.668 g cm(-3) for Z = 6. In the complex, two nitrogen atoms (from phen) and eight oxygen atoms (six from three bidentate nitrate anions and two from water molecules) are coordinated to the central La(III) ion, forming a coordination polyhedron which is approximately a bicapped square antiprism. The coordinated water molecules donate hydrogen bonds to the oxygen atoms of the crown ether, forming polymeric hydrogen bonded chains which wrap helically along the unit cell direction c.
Resumo:
Reaction of [Ph(4)P]2WS4 With NiCl2 in methanol solution in the presence of NaOCH3 leads to the formation of [Ph(4)P](2) [S2W(mu-S)(2)Ni(S-2)] (I) A Similar reaction between (NH4)(2)WS4 and NiCl2 under O-2 atmosphere in the presence of Ph(4)PCl or (n)Bu(4)NCl affords [Ph(4)P](2)([(S-2)W(O)(mu-S)(2)]Ni-2] (IIa) and [(n)Bu(4)N](2)([(S-2)W(O)(mu-S)(2)]Ni-2} (IIb) Under argon the same reaction gives [Ph(4)P](2)[Ni(WS4)(2)] (IIIa) and [(n)Bu(4)N](2)[Ni(WS4)(2)] (IIIb). [Ph(4)P](2)[Ni(WOS3)(2)] (IV) and [Ph(4)P](2)[Ni(WO2S2)(2)] (V) can be prepared from the reaction of [Ph(4)P]2WOS3 and [Ph(4)P]2WO2S2 with NiCl2. Treatment of (NH4)(2)WS4 with CuCl in the presence of PPh(3) in boiling pyridine produces W(mu-S)(4)Cu-2(PPh(3))(3) (VI), which can further react with excess PPh(3) to give W(mu-S)(4)Cu-2(PPh(3))(4) . py (VII). Complex I crystallizes in the space group P2(1)/n with the cell parameters: a = 20.049(4), b = 17.010(4), c = 14.311(7) Angstrom; beta = 110.24(3)degrees and Z = 4; R = 0.058 for 4267 independent reflections. The structural study confirms that complex I contains two terminal sulfide ligands, two bridging sulfide ligands, a side-on disulfide ligand, and a planar central W(mu-S)(2)Ni four membered ring. Complex VII crystallizes in the space group C2/c with the cell parameters: a = 26.436(8), b = 20.542(6), c = 19.095(8) Angstrom; beta = 125.00(3)degrees and Z = 4; R = 0.080 for 3802 independent reflections. The structural study reveals a perfect linear arrangement of the three metal atoms Cu-W-Cu.
Resumo:
A novel organic-inorganic hybrid compound [Cu(phen)](2)[(VV4As2O19)-V-IV-As-V-O-V].0.5H(2)O 1 has been hydrothermally synthesized. Its structure, determined by single crystal X-ray diffraction, exhibits an unusual two-dimensional arsenic vanadate layered network grafted with the [Cu(phen)](2+) complex. The chelating phen ligands project perpendicularly beyond the inorganic layer. Variable temperature magnetic susceptibility studies indicate that both ferro- and antiferro-magnetic interactions exist in 1.
Resumo:
In this paper, we will report the preparation of a mixed-valence polyoxometalate compound (Bu4N)(4)[PMo12O40].2DMF.H2O (TBA = tetrabutylammonium; DMF = N,N-dimethyl formamide). The title compound has been photochemically synthesized and characterized by using elemental analysis, IR, solid diffusion reflectance electronic spectra, ESR spectra, XPS, CV and X-ray single-crystal analysis. The crystal lographic data are as follows: monoclinic, P2(1)/c, a = 14.124(3), b = 17.481(4), c = 22.744(5) Angstrom, beta = 101.66(3)degrees, V = 5500(2) Angstrom(3), C70H160Mo12N6O43P, M-r = 2956.29, Z = 2, D-c = 1.785 g/cm(3), F(000) = 2970 and mu(MoKalpha) = 1.412 mm(-1). The structure has been refined to R = 0.0638 and wR = 0.1975 by full-matrix least-squares methods. The title compound is composed of four tetrabutylammonium cations, one [(PMoMo11O40)-Mo-V](4-) heteropoly anion, two N,N-dimethyl formamide and one H2O molecule.
Resumo:
A new vandylpolymolybdophosphate, [H2N(C2H4)(2)NH2](4)-(H3O)[(PMo2Mo6V4O40)-Mo-V-V-VI-O-IV((VO)-O-IV)(2)].H2O, was hydrothermally synthesized and structurally characterized by elemental analyses, IR, UV-vis, XPS, ESR spectra, mid singe crystal X-ray diffraction analysis. The compound contains an unusual highly reduced pseudo-Keggin type polyoxoanion with nine negative charges and exhibits an interesting phosphorus-centered alternate layer arrangement of molybdenum and vanadium oxides.
Resumo:
The title complex [(VB1)(2)DMFHPMo12O40.5DMF, VB1 = vitamin B-1 (thiamine chloride), DMF = N,N-dimethylformamide] has been synthesized and characterized by elemental analysis, IR, UV-Vis, electron spin resonance, X-ray photoelectron spectroscopy and cyclic voltammetry methods. The X-ray crystal structure revealed that there is one independent molecule in the unit cell of the title complex that contains one mixed-valence heteropolyanion, two VB1+ cations and six DMF molecules. The title complex possesses a centrosymmetrical arrangement in the unit cell, with the P atom at the symmetry center of the heteropolyanion and with eight O atoms surrounding the central P atom, such that two sets of PO4 tetrahedra are formed. The PO4 tetrahedra and MoO66-(7-) octahedra are disordered in the heteropolyanion. The bond distances of P-O-a and Mo=O-d are in the ranges 1.57 (4)-1.70 (4) Angstrom and 1.61 (2)-1.67 (2) Angstrom, respectively.