scholarly journals Crystal structure of strontium dinickel iron orthophosphate

2015 ◽  
Vol 71 (10) ◽  
pp. 1255-1258 ◽  
Author(s):  
Said Ouaatta ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Asymmetric Unit ◽  
Space Group ◽  
Edge Sharing Octahedra ◽  
Wyckoff Position

The title compound, SrNi2Fe(PO4)3, synthesized by solid-state reaction, crystallizes in an ordered variant of the α-CrPO4structure. In the asymmetric unit, two O atoms are in general positions, whereas all others atoms are in special positions of the space groupImma: the Sr cation and one P atom occupy the Wyckoff position 4e(mm2), Fe is on 4b(2/m), Ni and the other P atom are on 8g(2), one O atom is on 8h(m) and the other on 8i(m). The three-dimensional framework of the crystal structure is built up by [PO4] tetrahedra, [FeO6] octahedra and [Ni2O10] dimers of edge-sharing octahedra, linked through common corners or edges. This structure comprises two types of layers stacked alternately along the [100] direction. The first layer is formed by edge-sharing octahedra ([Ni2O10] dimer) linked to [PO4] tetrahedraviacommon edges while the second layer is built up from a strontium row followed by infinite chains of alternating [PO4] tetrahedra and FeO6octahedra sharing apices. The layers are held together through vertices of [PO4] tetrahedra and [FeO6] octahedra, leading to the appearance of two types of tunnels parallel to thea- andb-axis directions in which the Sr cations are located. Each Sr cation is surrounded by eight O atoms.

scholarly journals Crystal structure of disodium dicobalt(II) iron(III) tris(orthophosphate) with an alluaudite-like structure

2015 ◽  
Vol 71 (5) ◽  
pp. 558-560 ◽  
Author(s):  
Adam Bouraima ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Thomas Makani ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
General Position ◽  
Three Dimensional ◽  
The Other ◽  
Space Group ◽  
Open Framework ◽  
Wyckoff Position

The title compound, Na2Co2Fe(PO4)3, was synthesized by a solid-state reaction. This new stoichiometric phase crystallizes in an alluaudite-like structure. In this structure, all atoms are in general positions except for four atoms which are located at the special positions of theC2/cspace group. One Co atom, one P and one Na atom are all located on Wyckoff position 4e(2), while the second Na atom is located on an inversion centre 4a(-1). The other Co and Fe atoms occupy a general position with a statistical distribution. The open framework results from [(Co,Fe)2O10] units of edge-sharing [(Co,Fe)O6] octahedra, which alternate with [CoO6] octahedra that form infinite chains running along the [10-1] direction. These chains are linked together through PO4tetrahedra by the sharing of vertices so as to build layers perpendicular to [010]. The three-dimensional framework is accomplished by the stacking of these layers, leading to the formation of two types of tunnels parallel to [010] in which the Na+cations are located, each cation being surrounded by eight O atoms.

scholarly journals Substitution of indium for chromium in TlIn5−xCrxSe8: crystal structure of TlIn4.811(5)Cr0.189(5)Se8

2017 ◽  
Vol 73 (4) ◽  
pp. 500-502
Author(s):  
Robin Lefèvre ◽  
David Berthebaud ◽  
Franck Gascoin
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
The Other ◽  
Site Symmetry ◽  
Space Group ◽  
Eds Analysis ◽  
Wyckoff Position ◽  
Different Types

The new thallium penta(indium/chromium) octaselenide, TlIn4.811(5)Cr0.189(5)Se8, has been synthesized by solid-state reaction. It crystallizes isotypically with TlIn5Se8in the space groupC2/m. Although the two Tl positions are disordered and only partially occupied, no Tl deficiency was observed. The insertion of chromium in the structure has been confirmed by EDS analysis. Chromium substitutes indium exclusively at one of three In sites,viz.at one of the positions with site symmetry 2/m(Wyckoff position 2a). In the crystal structure, edge-sharing InSe6octahedra, and (In,Cr)Se6octahedra and InSe4tetrahedra make up two types of columns that are linked into a framework in which two different types of channels parallel to [010] are present. The Tl atoms are located in the larger of the channels, whereas the other, smaller channel remains unoccupied.

scholarly journals Na3Co2(As0.52P0.48)O4(As0.95P0.05)2O7

2013 ◽  
Vol 69 (12) ◽  
pp. i85-i86 ◽  
Author(s):  
Youssef Ben Smida ◽  
Abderrahmen Guesmi ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
General Position ◽  
Structural Model ◽  
Three Dimensional ◽  
The Other ◽  
Coordination Polyhedra ◽  
Bond Valence Sum ◽  
Full Occupancy

The title compound, trisodium dicobalt(II) (arsenate/phosphate) (diarsenate/diphosphate), was prepared by a solid-state reaction. It is isostructural with Na3Co2AsO4As2O7. The framework shows the presence of CoX22O12(X2 is statistically disordered with As0.95P0.05) units formed by sharing corners between Co1O6octahedra andX22O7groups. These units form layers perpendicular to [010]. Co2O6octahedra andX1O4(X1 = As0.54P0.46) tetrahedra form Co2X1O8chains parallel to [001]. Cohesion between layers and chains is ensured by theX22O7groups, giving rise to a three-dimensional framework with broad tunnels, running along thea- andc-axis directions, in which the Na+ions reside. The two Co2+cations, theX1 site and three of the seven O atoms lie on special positions, with site symmetries 2 andmfor the Co,mfor theX1, and 2 andm(× 2) for the O sites. One of two Na atoms is disordered over three special positions [occupancy ratios 0.877 (10):0.110 (13):0.066 (9)] and the other is in a general position with full occupancy. A comparison between structures such as K2CdP2O7, α-NaTiP2O7and K2MoO2P2O7is made. The proposed structural model is supported by charge-distribution (CHARDI) analysis and bond-valence-sum (BVS) calculations. The distortion of the coordination polyhedra is analyzed by means of the effective coordination number.

scholarly journals β-Li0.37Na0.63Fe(MoO4)2

2014 ◽  
Vol 70 (2) ◽  
pp. i9-i10 ◽  
Author(s):  
Amira Souilem ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
General Position ◽  
Site Occupancy ◽  
The Other ◽  
Main Structure ◽  
Axis Direction ◽  
A Site

The title compound, lithium/sodium iron(III) bis[orthomolybdate(VI)], was obtained by a solid-state reaction. The main structure units are an FeO6octahedron, a distorted MoO6octahedron and an MoO4tetrahedron sharing corners. The crystal structure is composed of infinite double MoFeO11chains along theb-axis direction linked by corner-sharing to MoO4tetrahedra so as to form Fe2Mo3O19ribbons. The cohesion between ribbonsviamixed Mo—O—Fe bridges leads to layers arranged parallel to thebcplane. Adjacent layers are linked by corners shared between MoO4tetrahedra of one layer and FeO6octahedra of the other layer. The Na+and Li+ions partially occupy the same general position, with a site-occupancy ratio of 0.631 (9):0.369 (1). A comparison is made withAFe(MoO4)2(A= Li, Na, K and Cs) structures.

Tetrakis(phenylethynyl)tin(IV)

2007 ◽  
Vol 63 (11) ◽  
pp. m2762-m2762 ◽  
Author(s):  
Mohammed Lahcini ◽  
Minna T. Räisänen ◽  
Pascal M. Castro ◽  
Martti Klinga ◽  
Markku Leskelä
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Title Compound ◽  
Triple Bond ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Tetrahedral Symmetry ◽  
Acetylenic Bond ◽  
Dimensional Network ◽  
Phenyl Proton

The asymmetric unit of the crystal structure of the title compound, [Sn(C8H5)4], consists of one fourth of a discrete tin complex and one half of another which both possess nearly ideal tetrahedral symmetry; the site symmetries of the two Sn atoms are \overline4 and 2. The bond angles at all acetylide C atoms are almost linear. The Sn—C distances [2.076 (6) and 2.065 (6)–2.069 (6) Å in the two complexes) are short when compared to the sum of the covalent radii of C and Sn (2.177 Å), but consistent with another tetrakis(alkynyl)tin complex. The acetylenic bond distances [1.196 (7) and 1.183 (7)–1.207 (7) Å] are consistent with a triple C[triple-bond]C bond. Therefore, despite the short Sn—C distances, the ligands are mainly σ-bonded to the metal. In the solid state, these complexes form a three-dimensional network via agostic C—H interactions as a phenyl proton in the ortho position interacts with the acetylenic carbon in the α position to the tin center.

scholarly journals Crystal structure of strontium dicobalt iron(III) tris(orthophosphate): SrCo2Fe(PO4)3

2016 ◽  
Vol 72 (8) ◽  
pp. 1143-1146 ◽  
Author(s):  
Adam Bouraima ◽  
Thomas Makani ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
Three Dimensional ◽  
Type Structure ◽  
Zigzag Chain ◽  
Common Edge ◽  
Linear Chains ◽  
Dimensional Network

The title compound, SrCo2Fe(PO4)3, has been synthesized by a solid-state reaction. It crystallizes with the α-CrPO4type structure. In this structure, all atoms are on special positions of theImmaspace group, except for two O atoms which are located on general positions. The three-dimensional network in the crystal structure is made up of two types of layers stacked normal to (100). The first layer is built from two edge-sharing CoO6octahedra, leading to the formation of Co2O10dimers that are connected to two PO4tetrahedra by a common edge and corners. The second layer results from apex-sharing FeO6octahedra and PO4tetrahedra, which form linear chains alternating with a zigzag chain of SrIIcations. These layers are linked together by common vertices of PO4tetrahedra and FeO6octahedra to form an open three-dimensional framework that delimits two types of channels parallel to [100] and [010] where the SrIIcations are located. Each SrIIcation is surrounded by eight O atoms.

scholarly journals Synthesis and crystal structure of calcium dizinc iron(III) tris(orthophosphate), CaZn2Fe(PO4)3

2016 ◽  
Vol 72 (9) ◽  
pp. 1260-1262 ◽  
Author(s):  
Jamal Khmiyas ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystals ◽  
Solid State Reaction ◽  
Three Dimensional ◽  
Asymmetric Unit ◽  
Common Edge ◽  
Conventional Solid State Reaction ◽  
Synthesis And Crystal Structure ◽  
A Chain

Single crystals of the title compound, CaZn2Fe(PO4)3, were synthesized by conventional solid-state reaction. In the asymmetric unit, all atoms are located in fully occupied general positions of theP21/cspace group. The zinc atoms are located on two crystallographically independent sites with tetrahedral and distorted triangular-based bipyramidal geometries. Two edge-sharing triangular bipyramidal ZnO5units form a dimer, which is linked to slightly deformed FeO6octahedraviaa common edge. The resulting chains are interconnected through PO4tetrahedra to form a layer perpendicular to thebaxis. Moreover, the remaining PO4and ZnO4tetrahedra are linked together through common vertices to form tapes parallel to thecaxis and surrounding a chain of Ca2+cations to build a sheet, also perpendicular to thebaxis. The stacking of the two layers along thebaxis leads to the resulting three-dimensional framework, which defines channels in which the Ca2+cations are located, each cation being coordinated by seven oxygen atoms.

scholarly journals 3,4-Dibromo-2,2,5,5-tetraphenyl-2,5-dihydrofuran

IUCrData ◽  
2018 ◽  
Vol 3 (4) ◽  
Author(s):  
Nadine Seidel ◽  
Wilhelm Seichter ◽  
Edwin Weber
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Three Dimensional ◽  
Supramolecular Network ◽  
Asymmetric Unit ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Compound C ◽  
Phenyl Rings

The crystal structure of the title compound, C28H20Br2O, was solved in the orthorhombic space group P212121 with one molecule in the asymmetric unit. The phenyl rings are nearly planar and inclined at angles of 67.7 (1), 68.8 (1), 79.3 (1) and 62.3 (1)° to the plane of the 2,5-dihydrofuran ring. The crystal structure features C—H...π and Br...Br interactions, which connect the molecules to a three-dimensional supramolecular network.

scholarly journals Crystal structure of alluaudite-type Na4Co(MoO4)3

2014 ◽  
Vol 70 (9) ◽  
pp. i47-i48 ◽  
Author(s):  
Rawia Nasri ◽  
Noura Fakhar Bourguiba ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Structural Feature ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Solid State Reactions ◽  
Main Structural Feature

The title compound, tetrasodium cobalt(II) tris[molybdate(IV)], was prepared by solid-state reactions. The structure is isotypic with Na3In2(AsO4)3and Na3In2(PO4)3. The main structural feature is the presence of infinite chains of edge-sharingX2O10(X= Co/Na) dimers, which are linked by MoO4tetrahedra, forming a three-dimensional framework enclosing two types of hexagonal tunnels in which Na+cations reside. In this alluaudite structure, Co and Na atoms are located at the same general site with occupancies of 0.503 (5) and 0.497 (6), respectively. The other three Na and one of the two Mo atoms lie on special positions (site symmetries 2, -1, 2 and 2, respectively). The structure is compared with similar structures and other members of alluaudite family.

scholarly journals Ca5Zr3F22

2012 ◽  
Vol 68 (4) ◽  
pp. i23-i23 ◽  
Author(s):  
Abdelghani Oudahmane ◽  
Malika El-Ghozzi ◽  
Daniel Avignant
Keyword(s):  
Solid State ◽  
Single Crystals ◽  
Solid State Reaction ◽  
Title Compound ◽  
Three Dimensional ◽  
The Other ◽  
Site Symmetry ◽  
Coordination Numbers ◽  
Rotation Axes ◽  
Dimensional Network

Single crystals of Ca5Zr3F22, pentacalcium trizirconium docosafluoride, were obtained unexpectedly by solid-state reaction between CaF2and ZrF4in the presence of AgF. The structure of the title compound is isotypic with that of Sr5Zr3F22and can be described as being composed of layers with composition [Zr3F20]8−made up from two different [ZrF8]4−square antiprisms (one with site symmetry 2) by corner-sharing. The layers extending parallel to the (001) plane are further linked by Ca2+cations, forming a three-dimensional network. Amongst the four crystallographically different Ca2+ions, three are located on twofold rotation axes. The Ca2+ions exhibit coordination numbers ranging from 8 to 12, depending on the cut off, with very distorted fluorine environments. Two of the Ca2+ions occupy interstices between the layers whereas the other two are located in void spaces of the [Zr3F20]8−layer and alternate with the two Zr atoms along [010]. The crystal under investigation was an inversion twin.

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