scholarly journals β-K3Fe(MoO4)2Mo2O7

2014 ◽  
Vol 70 (7) ◽  
pp. i38-i38 ◽  
Author(s):  
Amira Souilem ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Title Compound ◽  
Point Group ◽  
Coordination Numbers ◽  
Group Symmetries

The title compound, tripotassium iron(III) bis(orthomolybdate) dimolybdate, was obtained by a solid-state reaction. The main structural building units are one FeO6octahedron, two MoO4tetrahedra and one Mo2O7dimolybdate group, all with point group symmetriesm. These units are linkedviacorner-sharing to form ribbons parallel to [010]. The three K+cations are located between the ribbons on mirror planes and have coordination numbers of 10 and 12. Two O atoms of one of the MoO4tetrahedra of the dimolybdate group are disordered over two positions in a 0.524 (11):0.476 (11) ratio. The structure of the title compound is compared briefly with that of Rb3FeMo4O15.

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 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.

scholarly journals Sc0.43(2)Rb2Mo15S19, a partially Sc-filled variant of Rb2Mo15S19

2012 ◽  
Vol 68 (5) ◽  
pp. i25-i28 ◽  
Author(s):  
Patrick Gougeon ◽  
Rabih Al Rahal Al Orabi ◽  
Régis Gautier ◽  
Michel Potel
Keyword(s):  
Charge Transfer ◽  
Solid State ◽  
Unique Feature ◽  
Point Group ◽  
Tight Binding ◽  
Median Plane ◽  
Structural Motif ◽  
Space Group ◽  
Group Symmetries ◽  
Cluster Unit

The structure of scandium dirubidium pentadecamolybdenum nonadecasulfide, Sc0.43 (2)Rb2Mo15S19, constitutes a partially Sc-filled variant of Rb2Mo15S19[Picard, Saillard, Gougeon, Noel & Potel (2000),J. Solid State Chem.155, 417–426]. In the two compounds, which both crystallize in theR\overline{3}cspace group, the structural motif is characterized by a mixture of Mo6Si8Sa6and Mo9Si11Sa6cluster units (`i' is inner and `a' is apical) in a 1:1 ratio. The two components are interconnected through interunit Mo—S bonds. The cluster units are centred at Wyckoff positions 6band 6a(point-group symmetries \overline{3}. and 32, respectively). The Rb+cations occupy large voids between the different cluster units. The Rb and the two inner S atoms lie on sites with 3. symmetry (Wyckoff site 12c), and the Mo and S atoms of the median plane of the Mo9S11S6cluster unit lie on sites with .2 symmetry (Wyckoff site 18e). A unique feature of the structure is a partially filled octahedral Sc site with \overline{1} symmetry. Extended Hückel tight-binding calculations provide an understanding of the variation in the Mo—Mo distances within the Mo clusters induced by the increase in the cationic charge transfer due to the insertion of Sc.

Monomeres [(Me3Si)2CH]2Al-Te-Al[CH(SiMe3)2]2 mit gewinkelter Al-Te-Al-Gruppe / Monomeric [(Me3Si)2CH]2Al-Te-Al[CH(SiMe3)2] 2 with a Bent Al-Te-Al Group

1994 ◽  
Vol 49 (7) ◽  
pp. 931-934 ◽  
Author(s):  
Werner Uhl ◽  
Uwe Schütz
Keyword(s):  
Solid State ◽  
Bond Length ◽  
Title Compound ◽  
Single Bond ◽  
Hindered Rotation ◽  
Coordination Numbers ◽  
Mild Conditions ◽  
High Yields

AbstractTetrakis[bis(trimethylsilyl)methyl]dialane(4) 1 with an Al-Al bond and Et3P+-Te- give under mild conditions the title compound R2Al-Te-AlR2 (R = CH(SiMe3)2) 2 in high yields. Due to the high steric shielding 2 is monomeric even in the solid state with an angled Al-Te-Al group (110.4°) and an Al-Te bond length of 254.9 pm as expected for a Al-T e single bond with the atoms in low coordination numbers. A hindered rotation of the bulky substituents is observed in solution probably caused by steric restrictions similar that in ana­logous compounds with Al-S-Al or Al-CH2-Al groups.

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 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 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.

The Silver(I) Mercury(II) Oxide Nitrate with the Empirical Formula AgHg2NO5

1999 ◽  
Vol 54 (12) ◽  
pp. 1489-1494 ◽  
Author(s):  
Thomas J. Mormann ◽  
Wolfgang Jeitschko
Keyword(s):  
Crystal Structure ◽  
Solid State ◽  
Single Crystal ◽  
Solid State Reaction ◽  
Title Compound ◽  
Empirical Formula ◽  
Variable Parameters ◽  
Structure Factors ◽  
Linear Coordination ◽  
Oxygen Atoms

The title compound was prepared by solid state reaction of Ag2O with Hg(NO3)2· H2O in air at 350 °C. Its crystal structure was determined from single-crystal diffractometer data: Pnma, a = 620.1(1) pm, b = 670.1(1) pm, c = 1267.5(2) pm, Z = 4, R = 0.026 for 586 structure factors and 33 variable parameters. The compound may be represented by the formula Ag(HgO)2NO3 . The mercury(II) together with the oxygen atoms form zig-zag chains with linear coordination of the mercury atoms. The oxygen atoms of these chains are linked via silver(I) atoms, thus forming two-dimensionally infinite nets, which contain the trigonal planar nitrate groups in interstices. Thus, only secondary Hg-O and Ag-O bond are formed between the nets.

scholarly journals Rietveld refinement of the langbeinite-type phosphate K2Ni0.5Hf1.5(PO4)3

2020 ◽  
Vol 76 (10) ◽  
pp. 1634-1637
Author(s):  
Liang Zhou ◽  
Denys S. Butenko ◽  
Ivan V. Ogorodnyk ◽  
Nickolai I. Klyui ◽  
Igor V. Zatovsky
Keyword(s):  
Solid State ◽  
Rietveld Refinement ◽  
Title Compound ◽  
Three Dimensional ◽  
Solid State Method ◽  
Coordination Numbers ◽  
Rotation Axes ◽  
State Method

Polycrystalline potassium nickel(II) hafnium(IV) tris(orthophosphate), a langbeinite-type phosphate, was synthesized by a solid-state method. The three-dimensional framework of the title compound is built up from two types of [MO6] octahedra [the M sites are occupied by Hf:Ni in ratios of 0.754 (8):0.246 (8) and 0.746 (8):0.254 (8), respectively] and [PO4] tetrahedra are connected via O vertices. The K+ cations are located in two positions within large cavities of the framework, having coordination numbers of 9 and 12. The Hf, Ni and K sites lie on threefold rotation axes, while the P and O atoms are situated in general positions.

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