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 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 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.

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 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.

scholarly journals Elaboration, structural study and validation of a new NASICON-type structure, Na0.72(Cr0.48,Al1.52)(Mo2.77,Al0.23)O12

2018 ◽  
Vol 74 (3) ◽  
pp. 406-409
Author(s):  
Manel Sonni ◽  
Imen Jendoubi ◽  
Mohamed Faouzi Zid
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Structural Study ◽  
Solid State Reaction ◽  
Title Compound ◽  
Structural Model ◽  
Three Dimensional ◽  
Type Structure ◽  
Sodium Cations ◽  
Nasicon Type

The title compound, sodium chromium/aluminium molybdenum/aluminium dodecaoxide, Na0.72Cr0.48Al1.74Mo2.77O12, was prepared by solid-state reaction. Its crystal structure is related to NaSICON-type compounds. The framework is built up fromM1O6(M1 = Cr/Al) octahedra andM2O4(M2 = Mo/Al) tetrahedra interconnected by corners. The three-dimensional framework contains cavities in which sodium cations are located. Two validation models (BVS and CHARDI) were used to confirm the proposed structural model. The mobility of Na+ions in the structure has been investigated by theoretical means.

scholarly journals Elaboration, étude structurale et analyse CHARDI et BVS d'une nouvelle variété β-Na9Cr(MoO4)6de type alluaudite

2016 ◽  
Vol 72 (6) ◽  
pp. 833-837 ◽  
Author(s):  
Manel Sonni ◽  
Riadh Marzouki ◽  
Mohamed Faouzi Zid ◽  
Amira Souilem
Keyword(s):  
Solid State ◽  
Charge Distribution ◽  
Title Compound ◽  
Structural Model ◽  
Three Dimensional ◽  
Type Structure ◽  
Solid State Reactions ◽  
Site Symmetry ◽  
Hexagonal Form ◽  
Bond Valence Sum

The title compound, nonasodium chromium(III) hexakis[molybdate(VI)], β-Na9CrMo6O24, was prepared by solid-state reactions. This alluaudite-type structure is constituted of infinite layers formed by links betweenM2O10(M= C/Na) dimers and MoO4tetrahedra. The Na+and Cr3+cations are located in the same site with, respectively, 0.25 and 0.75 occupancies. The layers are connected to each other through MoO4sharing corners, resulting an in open three-dimensional framework with hexagonal-form cavities occupied by Na+cations. The proposed structural model is supported by charge-distribution (CHARDI) and bond-valence-sum (BVS) analysis. All atoms are on general positions except for one Mo, two Na (site symmetry 2) and another Na site (site symmetry -1). A comparison is made with the similar structures Na4Co(MoO4)3, Na2Ni(MoO4)2, Cu1.35Fe3(PO4)3and NaAgFeMn2(PO4)3.

scholarly journals Bis[tris(propane-1,3-diamine-κ2N,N′)nickel(II)] diaquabis(propane-1,3-diamine-κ2N,N′)nickel(II) hexabromide dihydrate

2014 ◽  
Vol 70 (6) ◽  
pp. m227-m228 ◽  
Author(s):  
Aymen Yangui ◽  
Walid Rekik ◽  
Slim Elleuch ◽  
Younes Abid
Keyword(s):  
Hydrogen Bonds ◽  
Title Compound ◽  
General Position ◽  
Three Dimensional ◽  
The Other ◽  
Octahedral Coordination ◽  
Water Molecules ◽  
Coordination Environment ◽  
Lattice Water ◽  
Dimensional Network

In the title compound, [Ni(C3H10N2)3]2[Ni(C3H10N2)2(H2O)2]Br6·2H2O, one Ni2+cation, located on an inversion centre, is coordinated by four N atoms from two ligands and by two water O atoms. The other Ni2+cation, located in a general position, is coordinated by six N atoms from three ligands. In both cases, the Ni2+cation has an octahedral coordination environment. The overall structural cohesion is ensured by three types of hydrogen bonds, N—H...Br, O—H...Br and O—H...O, which connect the two types of complex cations, the bromide counter-anions and the lattice water molecules into a three-dimensional network.

scholarly journals β-Nb9VO25

2014 ◽  
Vol 70 (5) ◽  
pp. i20-i20 ◽  
Author(s):  
Rawia Nasri ◽  
Saïda Fatma Chérif ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
Three Dimensional ◽  
Structural Differences

The title compound, nonaniobium vanadium pentacosaoxide, was prepared by a solid-state reaction at 1198 K. It is isotypic with Nb9AsO25, Nb9PO25and Ta9VO25. The structure consists of NbO6octahedra (one with 4/m.. and two withm.. symmetry) and VO4tetrahedra (-4.. symmetry) sharing corners and edges to form a three-dimensional framework. This framework can be considered as a junction between ribbons made up from NbO6octahedra and chains of NbO6octahedra and chains of VO4tetrahedra. The V site shows half-occupancy, hence one half of the VO4tetrahedra is unoccupied. The structural differences with α-Nb9VO25, VOSO4, SbOPO4and NbOPO4oxides are discussed.

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 Crystal structure of silver strontium copper orthophosphate, AgSr4Cu4.5(PO4)6

2020 ◽  
Vol 76 (2) ◽  
pp. 186-191 ◽  
Author(s):  
Jamal Khmiyas ◽  
Elhassan Benhsina ◽  
Said Ouaatta ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Structural Model ◽  
Hydrothermal Process ◽  
Three Dimensional ◽  
Distribution Analysis ◽  
Asymmetric Unit ◽  
Ionic Bonds ◽  
Bond Valence Sum ◽  
Oxygen Anions

Crystals of the new compound, AgSr4Cu4.5(PO4)6, were grown successfully by the hydrothermal process. The asymmetric unit of the crystal structure of the title compound contains 40 independent atoms (4 Sr, 4.5 Cu, 1 Ag, 6 P and 24 O), which are all in general positions except for one Cu atom, which is located on an inversion centre. The Cu atoms are arranged in CuO n (n = 4 or 5) polyhedra, linked through common oxygen corners to build a rigid three-dimensional motif. The connection of these copper units is assured by PO4 tetrahedra. This arrangement allows the construction of layers extending parallel to the (100) plane and hosts suitable cavities in which Ag+ and Sr2+ cations are located. The crystal-structure cohesion is ensured by ionic bonds between the silver and strontium cations and the oxygen anions belonging to two adjacent sheets. Charge-distribution analysis and bond-valence-sum calculations were used to validate the structural model.

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