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1.
The crystal structure of synthetic penkvilksite‐2O, disodium titanium tetrasilicate dihydrate, Na2TiSi4O11·2H2O, a microporous titanosilicate, confirms the major features of a previous model that had been obtained by order–disorder (OD) theory from the known structure of penkvilksite‐1M. An important difference from the previous model involves the hydrogen bonding of the water molecule which, on the basis of a Raman spectrum and the finding of only one of the two H atoms, is proposed to be disordered about a fixed O–H direction. The structure of penkvilksite‐2O is based on (100) silicate layers linked by isolated TiO6 octahedra to form a heteropolyhedral framework. The layer is strongly corrugated, based on interlaced spiral chains, and is crossed by two different channels that have an effective channel width of about 3 Å.  相似文献   

2.
In the title compound, [Mn(C5H2N2O4)(H2O)2]n, the MnII ion has a distorted octahedral geometry and the 4‐oxido‐2‐oxo‐1,2‐dihydropyrimidine‐5‐carboxylate (Hiso2−) anion acts as a μ34‐bridging ligand. Two oxo O atoms from different Hiso2− ligands bridge two MnII ions, forming centrosymmetric dinuclear building blocks. Each dinuclear building block interacts with another four by the coordination of the oxide groups and carboxylate O atoms, producing a two‐dimensional framework in the ab plane. Hydrogen bonds further extend the two‐dimensional sheets into a three‐dimensional supramolecular framework.  相似文献   

3.
In the title compound, [Ca(C6H5O4)2(C6H6O4)2]·4H2O, which is a kojic acid–Ca2+ complex, the Ca atom is on a twofold axis and is octacoordinated by O atoms from four pyrone ligand mol­ecules. The hydroxyl and ketone O atoms of each ligand form a five‐membered chelate ring with the Ca atom. The crystal structure is stabilized by partial stacking and O—H?O hydrogen bonds.  相似文献   

4.
β‐CdC2O4     
Crystals of an­hydrous cadmium oxalate, β‐[Cd(C2O4)], have been synthesized hydro­thermally and the crystal structure solved using single‐crystal X‐ray diffraction data. The Cd and oxalate ions lie about independent inversion centres. The structure consists of a three‐dimensional framework built from sheets of cadmium octahedra linked together by oxalate groups.  相似文献   

5.
The complexes cis‐[SnCl4(H2O)2]·2H2O ( 1 ), [Sn2Cl6(OH)2(H2O)2]·4H2O ( 3 ), and [HL][SnCl5(H2O)]·2.5H2O ( 4 ) were isolated from a CH2Cl2 solution of equimolar amounts of SnCl4 and the ligand L (L=3‐acetyl‐5‐benzyl‐1‐phenyl‐4, 5‐dihydro‐1, 2, 4‐triazine‐6‐one oxime, C18H18N4O2) in the presence of moisture. 1 crystallizes in the monoclinic space group Cc with a = 2402.5(1) pm, b = 672.80(4) pm, c = 1162.93(6) pm, β = 93.787(6)° and Z = 8. 4 was found to crystallize monoclinic in the space group P21, with lattice parameters a = 967.38(5) pm, b = 1101.03(6) pm, c = 1258.11(6) pm, β = 98.826(6)° and Z = 2. The cell data for the reinvestigated structures are: [SnCl4(H2O)2]·3H2O ( 2 ): a = 1227.0(2) pm, b = 994.8(1) pm, c = 864.0(1) pm, β = 103.86(1)°, with space group C2/c and Z = 4; 3 : a = 961.54(16) pm, b = 646.29(7) pm, c = 1248.25(20) pm, β = 92.75(1)°, space group P21/c and Z = 4.  相似文献   

6.
7.
A stochastic investigation of lithium deinsertion from individual 200‐nm‐sized particles of LiMn2O4 reveals the rate‐determining step at high overpotentials to be the transfer of the cation across the particle–electrolyte interface. Measurement of the (electro)chemical behavior of the spinel is undertaken without forming a conductive composite electrode. The kinetics of the interfacial ion transfer defines a theoretical upper limit for the discharge rates of batteries using LiMn2O4 in an aqueous environment.  相似文献   

8.
9.
On Copper‐tetrahydrogen‐decaoxo‐diperiodate‐hexahydrate CuH4I2O10·6H2O: Crystal Structure, Vibrational Spectroscopy and Thermal Analysis By crystallization from a strongly acidic aqueous solution copper‐tetrahydrogen‐decaoxodiperiodate‐hexahydrate CuH4I2O10· 6H2O has been obtained. In the structure of this compound (S.G. P 21/c, Nr.14), Z = 2, a = 1060.2(2) pm, b = 551.1(1) pm, c = 1164.7(2) pm, β = 111, 49(3)°) centrosymmetric [H4I2O10]2— anions in the form of two edge sharing octahedra form layers via hydrogen bonds originating from the acidic, trans‐configurated OH groups of the anions. Raman spectra are given and analyzed with respect to the internal vibrations of the periodate anion. The dehydration of the compound takes place via CuH4I2O10·3H2O and Cu(H2IO5)2 which decomposes at 170 °C to Cu(IO3)2.  相似文献   

10.
The title complex, {[Zn(C8H3NO6)(H2O)3]·H2O}n, has a one‐dimensional chain structure. The two carboxylate groups of the dianionic 2‐nitroterephthalate ligand adopt mono‐ and bidentate chelating modes. The Zn atom shows distorted octahedral coordination, bonded to three O atoms from two carboxylate groups and three O atoms of three non‐equivalent coordinated water molecules. The one‐dimensional chains are aggregated into two‐dimensional layers through inter‐chain hydrogen bonding. The whole three‐dimensional structure is further stabilized by inter‐layer hydrogen bonds.  相似文献   

11.
The indium oxide‐borate In4O2B2O7 was synthesized under high‐pressure/high‐temperature conditions at 12.5 GPa/1420 K using a Walker‐type multianvil apparatus. Single‐crystal X‐ray structure elucidation showed edge‐sharing OIn4 tetrahedra and B2O7 units building up the oxide‐borate. It crystallizes with Z = 8 in the monoclinic space group P21/n (no. 14) with a = 1016.54(3), b = 964.55(3), c = 1382.66(4) pm, and β = 109.7(1)°. The compound was also characterized by powder X‐ray diffraction and vibrational spectroscopy.  相似文献   

12.
Increasing energy demands and worsening environmental issues have stimulated intense research on alternative energy storage and conversion systems including supercapacitors and fuel cells. Here, a rationally designed hierarchical structure of ZnCo2O4@NiCo2O4 core–sheath nanowires synthesized through facile electrospinning combined with a simple co‐precipitation method is proposed. The obtained core–sheath nanostructures consisting of mesoporous ZnCo2O4 nanowires as the core and uniformly distributed ultrathin NiCo2O4 nanosheets as the sheath, exhibit excellent electrochemical activity as bifunctional materials for supercapacitor electrodes and oxygen reduction reaction (ORR) catalysts. Compared with the single component of either ZnCo2O4 nanowires or NiCo2O4 nanosheets, the hierarchical ZnCo2O4@NiCo2O4 core–sheath nanowires demonstrate higher specific capacitance of 1476 F g?1 (1 A g?1) and better rate capability of 942 F g?1 (20 A g?1), while maintaining 98.9 % capacity after 2000 cycles at 10 A g?1. Meanwhile, the ZnCo2O4@NiCo2O4 core–sheath nanowires reveal comparable catalytic activity but superior stability and methanol tolerance over Pt/C as ORR catalyst. The impressive performance may originate from the unique hierarchical core–sheath structures that greatly facilitate enhanced reactivity, and faster ion and electron transfer.  相似文献   

13.
Hexaaquamagnesium(II) sulfate pentahydrate, [Mg(H2O)6]SO4·5H2O, and hexaaquamagnesium(II) chromate(II) pentahydrate, [Mg(H2O)6][CrO4]·5H2O, are isomorphous, being composed of hexaaquamagnesium(II) octahedra, [Mg(H2O)6]2+, and sulfate (chromate) tetrahedral oxyanions, SO42− (CrO42−), linked by hydrogen bonds. There are two symmetry‐inequivalent centrosymmetric octahedra: M1 at (0, 0, 0) donates hydrogen bonds directly to the tetrahedral oxyanion, T1, at (0.405, 0.320, 0.201), whereas the M2 octahedron at (0, 0, ) is linked to the oxyanion via five interstitial water molecules. Substitution of CrVI for SVI leads to a substantial expansion of T1, since the Cr—O bond is approximately 12% longer than the S—O bond. This expansion is propagated through the hydrogen‐bonded framework to produce a 3.3% increase in unit‐cell volume; the greatest part of this chemically induced strain is manifested along the b* direction. The hydrogen bonds in the chromate compound mitigate ∼20% of the expected strain due to the larger oxyanion, becoming shorter (i.e. stronger) and more linear than in the sulfate analogue. The bifurcated hydrogen bond donated by one of the interstitial water molecules is significantly more symmetrical in the chromate analogue.  相似文献   

14.
The crystal structures of the title iron(III) and aluminium(III) ethyl maltolate complexes, [Fe(C7H7O3)3] and [Al(C7H7O3)3], respectively, are isomorphous. In each case, the three bidentate ligand mol­ecules are bound to the metal atom, forming a distorted octahedral coordination geometry in a fac configuration.  相似文献   

15.
The title compound, [Cu4(C7H4ClO2)4(C6H6NO)4], consists of isolated tetranuclear clusters, where the Cu2+ cations are five‐ and sixfold coordinated by O atoms from the 4‐chlorobenzoate anions and by pyridine N and methanolate O atoms from bidentate 2‐pyridylmethanolate ligands. While three Cu atoms are six‐coordinated by an NO5 donor set forming distorted octahedra, the fourth Cu atom is five‐coordinated by an NO4 donor set forming a distorted tetragonal–pyramidal coordination around the Cu atom. The nucleus is a deformed cubane‐like Cu4O4 structure, with Cu...Cu distances in the range 3.0266 (11)–3.5144 (13) Å.  相似文献   

16.
The title compound, {[Mn(C4H4O6)(C12H8N2)]·6H2O}n, has a linear chain structure containing monomeric [Mn(C4H4O6)(C12H8N2)] repeat units. Each manganese ion is six‐coordinate, with the two phenanthroline N atoms [Mn—N = 2.229 (2) and 2.235 (2) Å] and four O atoms from two tartrate anions [Mn—OCOO = 2.1252 (19) and 2.1310 (19) Å, and Mn—OOH = 2.2404 (19) and 2.2424 (19) Å] forming a seriously distorted octahedral coordination environment. Six water mol­ecules exist outside every repeat unit as solvate mol­ecules. Extensive hydrogen‐bonding interactions and π–π stacking of the phenanthroline moieties exist between the chains.  相似文献   

17.
The title compound, [La2(C8H3NO6)2(C8H4NO6)2(H2O)6]·2H2O, consists of dimeric units related by an inversion center. The two LaIII atoms are linked by two bridging bidentate carboxyl­ate groups and two monodentate carboxyl­ate groups. Each LaIII atom is nine‐coordinated by six O atoms from five different carboxyl­ate groups and three from water mol­ecules. Hydrogen bonds between the water mol­ecules and between the solvent water and a carboxyl­ate O atom are observed in the structure. In the crystal packing, there are slipped π–π stacking inter­actions between the parallel benzene rings. Both hydrogen‐bonding and π–π inter­actions combine to stabilize the three‐dimensional supra­molecular network.  相似文献   

18.
In the title complex, [Zn(C8H3NO6)(H2O)3]n, the two carboxylate groups of the 4‐nitrophthalate dianion ligands have monodentate and 1,3‐bridging modes, and Zn atoms are interconnected by three O atoms from the two carboxylate groups into a zigzag one‐dimensional chain along the b‐axis direction. The Zn atom shows distorted octahedral coordination as it is bonded to three O atoms from carboxylate groups of three 4‐nitrophthalate ligands and to three O atoms of three non‐equivalent coordinated water molecules. The one‐dimensional chains are aggregated into two‐dimensional layers through inter‐chain hydrogen bonding. The whole three‐dimensional structure is further maintained and stabilized by inter‐layer hydrogen bonds.  相似文献   

19.
Cs4K2CuSi2O8: Synthesis, Crystal Structure, UV‐Vis‐IR Data Cs4K2CuSi2O8 may be obtained via a redox reaction of KCuO2 in the presence of Cs2O and SiO2 with the container material (Cu) at 450 °C as blue single crystals which are sensitive to moisture. Powder samples were obtained by annealing intimate mixtures of the binary oxides under an inert gas atmosphere (Ar) in sealed Ag containers at 500 °C. The crystal structure contains isolated trimeric anions of [O2SiO2CuO2SiO2]6–. Cu2+ in square‐planar coordination share trans‐edges with [SiO4] tetrahedra. Spectroscopic investigations focus on the bonding situation of the [CuO4] unit (AOM) and characteristic vibrational modes of the silicate.  相似文献   

20.
本文利用醋酸锌和草酸的一步低热固相化学反应制备了草酸锌空心纳米球,并通过在该反应体系中加入表面活性剂聚乙二醇400得到了草酸锌空心纳米链。采用X-射线粉末衍射(XRD)、透射电镜(TEM)、高倍透射电镜(HRTEM)、扫描电镜(SEM)、红外(IR) 以及热重-差热(TG/DTA)分析对所合成的样品进行了表征.  相似文献   

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