Liquid-Assisted Solid-State Reaction: Formation of a Three-Dimensional Hydrogen-Bonded Network and Evidence for Proton Induced Electron Transfer

2010 ◽  
Vol 10 (3) ◽  
pp. 1263-1268 ◽  
Author(s):  
Li-Fei Yang ◽  
Man-Li Cao ◽  
Ying Cui ◽  
Jin-Ji Wu ◽  
Bao-Hui Ye
2013 ◽  
Vol 69 (12) ◽  
pp. i85-i86 ◽  
Author(s):  
Youssef Ben Smida ◽  
Abderrahmen Guesmi ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

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.


2000 ◽  
Vol 104 (49) ◽  
pp. 11801-11804 ◽  
Author(s):  
Takashi Ikeda ◽  
Michiel Sprik ◽  
Kiyoyuki Terakura ◽  
Michele Parrinello

2007 ◽  
Vol 63 (11) ◽  
pp. i191-i191 ◽  
Author(s):  
P. Armand ◽  
D. Granier ◽  
A. van der Lee

The cubic structure of trirubidium molybdophosphate, Rb3[PMo12O40], contains α-type Keggin [PMo12O40]3− anions and Rb+ counter-ions located in orthogonally intersecting channels. The P and Rb atoms are located on special positions with site symmetries \overline{4}3m and \overline{4}2.m, respectively. The three-dimensional arrangement is isostructural with that found in, for example, X 3[PMo12O40], with X = K, NH4 and H3O, or X 3[PW12O40] and X 4[SiW12O40], with X = Ag and Tl. The compound was crystallized using a typical high-temperature solid-state reaction with GaPO4 and X 3Mo3O10 (X = Rb or Li) as starting materials.


2006 ◽  
Vol 62 (5) ◽  
pp. i114-i116 ◽  
Author(s):  
Mounir Hajji ◽  
Mohamed Faouzi Zid

Silver molybdyl arsenate has been synthesized by a solid-state reaction. The structure consists of AsO4 tetrahedra and MoO6 octahedra sharing corners to form a three-dimensional framwork containing channels running along [010], in which the Ag+ ions are located. Structural relationships between the different monoarsenates of the AMoO2AsO4 series (A = Ag, Li, Na, K and Rb) are discussed.


2009 ◽  
Vol 65 (6) ◽  
pp. i44-i44 ◽  
Author(s):  
Zhen-Hua Liang ◽  
Kai-Bin Tang ◽  
Qian-Wang Chen ◽  
Hua-Gui Zheng

Rubidium dicalcium triniobate(V), RbCa2Nb3O10, has been synthesized by solid-state reaction and its crystal structure refined from X-ray powder diffraction data using Rietveld analysis. The compound is a three-layer perovskite Dion–Jacobson phase with the perovskite-like slabs derived by termination of the three-dimensional CaNbO3perovskite structure along theabplane. The rubidium ions (4/mmmsymmetry) are located in the interstitial space.


2015 ◽  
Vol 71 (10) ◽  
pp. 1255-1258 ◽  
Author(s):  
Said Ouaatta ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari

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.


2014 ◽  
Vol 70 (5) ◽  
pp. i20-i20 ◽  
Author(s):  
Rawia Nasri ◽  
Saïda Fatma Chérif ◽  
Mohamed Faouzi Zid ◽  
Ahmed Driss

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.


Author(s):  
Adam Bouraima ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Thomas Makani ◽  
Lahcen El Ammari

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.


2001 ◽  
Vol 56 (11) ◽  
pp. 1238-1240 ◽  
Author(s):  
Andreas Nägele ◽  
Cynthia Day ◽  
Abdessadek Lachgar ◽  
H.-Jürgen Meyer

The solid state reaction of KCl, NbCl5 and Nb powder at 760 °C yielded black crystals of KNb6Cl15. The structure of the compound has been determined using single-crystal X-ray methods. KNb6Cl15 crystallizes in the orthorhombic space group Pmma (no. 51) with lattice constants a = 1780.1(2), b = 1341.4(1), and c = 925.5(1) pm, Z = 4, and R1 = 0.039 for all 2727 observed reflections.[(Nb6Cl12i)Cl6/2a-a]- anions in the structure are linked via two Cla-a bridges to form one set of linear and one set of kinked chains along the crystallographic c and a directions. Four remaining Cla-a bridges interconnect both sets of chains to a three-dimensional network. The potassium occupancy on a 4k site was refined to a value of 0.384(3) consistent with the formula K0.77Nb6Cl15-. Ternäre Niobchloride des Formeltyps ANb6Cl15 wurden bereits verschiedentlich beschrieben. Verbindungen mit A = Li [1] und Na [2] kristallisieren kubisch (Ia3̅d) mit identischen Schweratomstrukturen. Die Alkalimetall-Ionen Li (KZ = 4) und Na (KZ = 6 ) besetzen in den Strukturen ANb6Cl15 aber unterschiedliche Splitlagen und sind dynamisch fehlgeordnet. Die Vertreter mit A = In und TI [3] kristallisieren orthorhombisch (Pmma). Ihre Kationen befinden sich in zweifach überdachten, würfelförmigen Cl-Umgebungen (KZ = 10). Die Kenntnis des Formeltyps ANb6Cl15 mit schweren Alkalimetallen ist noch unvollständig. Einkristallstrukturuntersuchungen für A = Rb, Cs ergaben Kationenfehlordnungen [4, 5]. Für die Verbindung KNb6Cl15 wurde eine Einkristallstrukturbestimmung durchgeführt (Tab. 1). Die Verbindung kristallisiert orthorhombisch in der Raumgruppe Pmma (Nr. 51) mit den Gitterkonstanten a = 1780,1(2), b = 1341,4(1) und c = 925,5(1) pm mit Z = 4 und ist isotyp zu den Inund TI-Verbindungen. Die Besetzung der K-Position (4k-Lage, mx-Punktsymmetrie) wurde zu 0,384(3) verfeinert, was der Zusammensetzung K0.77Nb6Cl15 entspricht (Tab. 2)#. Die Nb-Nb-Abstände in KNb6Cl15 liegen zwischen 291,47(6) und 296,45(7) pm, die Bindungslängen Nb-ClI betragen 243,3(1) - 247,18(9) und die Nb-Cla-Abstände 258,7(2) - 271,40(9) pm.


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