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51.
A new mixed alkali/alkaline earth iron phosphate, NaBaFe4(HPO4)3.H2O, has been synthesized hydrothermally and structurally characterized by single-crystal X-ray diffraction, magnetic susceptibility, infrared spectroscopy, and thermogravimetric analysis. The title compound crystallizes in the monoclinic space group P2(1)/c (No. 14) with a = 9.287(2) A, b = 22.665(4) A, c = 8.966(3) A, beta = 91.82(2), and Z = 4. The compound has a 2-D framework structure constructed from layers, stacked along the [010] unit cell direction with Na+ and Ba2+ ions, and water molecules residing within the interlayer space. The anionic layers are composed from the assemblage of vertex shared FeO6 octahedra interconnected by PO4(3)- and HPO4(2)- tetrahedra. The layers are built from four unique FeO6 units linking through vertex shared oxygen atoms to form infinite zigzag chains that run parallel to the a axis. These chains form single layers that run infinitely in the c direction through the vertex sharing of PO4 groups. 相似文献
52.
Darrah Johnson‐McDaniel Dr. Sara Comer Prof. Joseph W. Kolis Prof. Tina T. Salguero 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(49):17560-17564
We describe the first hydrothermal synthesis of CaCuSi4O10 as micron‐scale clusters of thin platelets, distinct from morphologies generated under salt‐flux or solid‐state conditions. The hydrothermal reaction conditions are surprisingly specific: too cold, and instead of CaCuSi4O10, a porous calcium copper silicate forms; too hot, and calcium silicate (CaSiO3) forms. The precursors also strongly impact the course of the reaction, with the most common side product being sodium copper silicate (Na2CuSi4O10). Optimized conditions for hydrothermal CaCuSi4O10 formation from calcium chloride, copper(II) nitrate, sodium silicate, and ammonium hydroxide are 350 °C at 3000 psi for 72 h; at longer reaction times, competitive delamination and exfoliation causes crystal fragmentation. These results illustrate that CaCuSi4O10 is an even more unique material than previously appreciated. 相似文献
53.
Mehtap Emirdag-Eanes Mariusz Krawiec Joseph W. Kolis 《Journal of chemical crystallography》2001,31(5):281-285
NaLnGeO4 (Ln = Ho, Tb, Tm, Er, Yb, Lu) were, synthesized in supercritical water, and the products were obtained in quantitative yield as large single crystals. The crystal structures of the family of NaLnGeO4 were determined, and found to crystallize in the orthorhombic crystal system with the space group Pnma. The structures have olivine type chains as the primary building block, with GeO4 tetrahedra linking the chains through edge- and corner-sharing with lanthanide octahedral units. 相似文献
54.
Dr. Tiffany M. Smith Pellizzeri Dr. Colin D. McMillen Prof. Joseph W. Kolis 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(3):597-600
Materials with triangular arrangements of transition metal ions are of great interest for their complex magnetism resulting from geometric frustration. This paper describes the stepwise formation of kagome lattices of open shell transition-metal ions from half-delta chains to delta/sawtooth chains, and finally kagome nets. The systems can be viewed as a testbed for magnetic studies since a variety of spin states can be introduced across the same structure type, and progress through increasing levels of structural complexity and dimensionality. The synthetic and structural development of this continuum is studied here in well-formed single crystals of A2M3(MoO4)3(OH)2 (A=K, Rb; M=Mn, Co), CsM2(MoO4)2(OH) (M=Mn, Fe, Co, Zn), and KM3(MoO4)2O(OH) (M=Mn). 相似文献
55.
56.
A Cesium Rare‐Earth Silicate Cs3RESi6O15 (RE=Dy–Lu,Y, In): The Parent of an Unusual Structural Class Featuring a Remarkable 57 Å Unit Cell Axis 下载免费PDF全文
Rylan Terry Daniel Vinton Dr. Colin D. McMillen Prof. Joseph W. Kolis 《Angewandte Chemie (International ed. in English)》2018,57(8):2077-2080
The structure of Cs3RESi6O15, where RE=Dy–Lu, Y, In, is unusual in that it contains octahedrally coordinated rare‐earth ions; their relative orientation dictates the structure, as they rotate about the c‐axis supported by the cyclic Si6O15 framework. The repeat unit of the rotation is eight units generating a very long (ca. 57 Å) unit cell axis. This unusual repeat unit is created by the structural flexibility of the hexasilicate ring, which is in turn affected by the size of the rare earth ion as well as the size of alkali ion residing within the silicate layers. Previous work showed for the smaller Sc3+ ion, the rotation of the octahedra is not sufficient to achieve closure at an integral repeat unit and an incommensurate structure results. The products are prepared as large, high quality single crystals using a high‐temperature (650 °C) hydrothermal method with CsOH and F? mineralizers. The presence of fluoride is essential to the formation of the product. 相似文献
57.
Matthew Mann Joseph Kolis Don VanDerveer 《Acta Crystallographica. Section C, Structural Chemistry》2009,65(5):i27-i29
Potassium scandium niobate hydroxide, K3(Sc0.875Nb0.125)Nb2O9H1.75, is a new scandium niobate with a unique cage structure. The structure contains two non‐equivalent K+ sites (3m and m2 site symmetry), one disordered Sc3+/Nb5+ site (m site symmetry), one Nb5+ site (3m site symmetry), two O2− sites (m and mm2 site symmetry) and one H+ site (m site symmetry). Both scandium and niobium have octahedral environments, which combine to form cages around potassium. One K atom lies in a cube‐like cage built of seven octahedra, while the other K atom is encapsulated by an eight‐membered trigonal face‐bicapped prism. The cages form sheets that extend along the ab plane. 相似文献
58.
Several new hydrated rare earth vanadates and rare earth oxy-vanadates have been synthesized using hydrothermal techniques and characterized using single crystal and powder X-ray diffraction and infrared and UV-vis absorption spectroscopies. The hydrated rare earth vanadates adopt the space group P2(1)/m with general formula A(3)VO(5)(OH)(3) (A = Y (1), Dy (2), or La (3)) and contain anionic distorted square pyramidal [VO(5)](-6) units and AO(7) and AO(8) polyhedra. The oxy-vanadates with the general formula A(2)O(VO(4)) (A = Y (4), Dy (5; 6), or Yb (7)) form two polymorphs in either P2(1)/c or C2/c space groups and contain anionic tetrahedral [VO(4)](-4) units and nonvanadium bonded O(2-) anions in distorted [OA(4)] tetrahedra. In all cases, the vanadium ion is in the tetravalent oxidation state, and its original source was the trace V(4+) impurities in YVO(4). The observed vanadyl and equatorial vanadium-oxygen bond lengths about the square pyramid in compounds 1-3 and the tetrahedral vanadium coordination found in compounds 4-7 are unusual for V(4+). The electronic and vibrational spectra are also reported and correlated with the appropriate coordination environment. 相似文献
59.
The effect of dopant cesium (Cs(I)) over a concentration range from 1 to 10 mol% on the growth process, morphology, thermal and optical properties of tri(thiourea)zinc(II) sulfate (ZTS) single crystals grown by slow evaporation solution growth technique has been investigated. Incorporation of Cs(I) into the crystal lattice was well confirmed by energy dispersive X-ray spectroscopy (EDS). The lattice parameters of the as-grown crystals were obtained by single crystal X-ray diffraction analysis. The reduction in the intensities observed in powder X-ray diffraction patterns of doped specimen and slight shifts in vibrational frequencies in fourier transform infrared spectra (FT-IR) indicate the lattice stress as a result of doping. Thermal studies reveal the purity of the material and no decomposition is observed up to the melting point. High transmittance is observed in the visible region and the cut-off λ is ~280 nm. The surface morphology of the as-grown specimens was studied by scanning electron microscopy (SEM). The second harmonic generation (SHG) efficiency of the host crystal is enhanced greatly in the presence of high concentrations of the dopant. 相似文献
60.
Sanchez-Martinez C Faul MM Shih C Sullivan KA Grutsch JL Cooper JT Kolis SP 《The Journal of organic chemistry》2003,68(21):8008-8014
Synthesis of aryl- and hetero[a]pyrrolo[3,4-c]carbazoles by photochemical oxidation and Heck cyclization are described. Photochemical oxidation of 2-naphthyl indolyl maleimide affords two different carbazole regioisomers, depending on the reaction conditions. The regiochemistry of the cyclization can be controlled using the Heck reaction. 相似文献