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1.
Mourad Hidouri Besma Lajmi Ahmed Driss Mongi Ben Amara 《Journal of chemical crystallography》2004,34(10):669-672
A new monophosphate Na1.28Ni0.86Fe2(PO4)3 has been synthesized by a flux method and structurally characterized by single-crystal X-ray diffraction. The compound crystallizes in the orthorhombic space group Ibmm with the parameters: a = 6.438(2) Å, b = 10.515(3) Å, c = 13.166(3) Å, Z = 4. The structure is built up from Fe2O10 units of edge-sharing FeO6 octahedra, which are connected through the corners of MO6 (M = Ni2+ or a vacancy) octahedra and PO4 tetrahedra to form a three-dimensional framework analogous to that of -CrPO4. Of the two crystallographically distinct Na+ sites contained in this structure, one is totally filled whereas the other is 28% occupied. 相似文献
2.
A new type of trirubidium nonahydrogen tetraphosphate, Rb3H9(PO4)4, crystal has been crystallized. Differential scanning calorimetry (DSC) and X‐ray diffraction measurements have been performed on the title compound. The crystal does not undergo any structural phase transition in the temperature range from 120 to 440 K except a melting transition at 399 K. The compound belongs to a monoclinic system with space group C2/c at room temperature. The structure is built on a framework of PO4 tetrahedra linked by five types of OH‐O hydrogen bonds in the length range from 2.472(4) to 2.679(4) Å. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
3.
M. G. Zhizhin A. A. Filaretov A. V. Olenev V. V. Chernyshev F. M. Spiridonov L. N. Komissarova 《Crystallography Reports》2002,47(5):773-782
Double potassium indium and rubidium indium phosphates K3In(PO4)2 (I) and Rb3In(PO4)2 (II) are synthesized by solid-phase sintering at T = 900°C. The compounds prepared are characterized by X-ray powder diffraction (I and II), X-ray single-crystal diffraction (II), and laser-radiation second harmonic generation. Structure I is solved using the Patterson function and refined by the Rietveld method. Both compounds crystallize in the monoclinic crystal system. For crystals I, the unit cell parameters are as follows: a = 15.6411(1) Å, b = 11.1909(1) Å, c = 9.6981(1) Å, β = 90.119(1)°, space group C2/c, R p = 4.02%, and R wp = 5.25%. For crystals II, the unit cell parameters are as follows: a = 9.965(2) Å, b = 11.612(2) Å, c = 15.902(3) Å, β = 90.30(3)°, space group P21/n, R 1 = 4.43%, and wR 2 = 10.76%. Structures I and II exhibit a similar topology of the networks which are built up of { In[PO4]2} (I) and { In2[PO4]4} (II) structural units. 相似文献
4.
I. V. Ogorodnyk I. V. Zatovsky V. N. Baumer N. S. Slobodyanik O. V. Shishkin 《Crystal Research and Technology》2007,42(11):1076-1081
Two potassium lanthanide zirconium orthophosphates with general composition K1.822Nd0.822Zr1.178(PO4)3 (KNdZrP) and K2LuZr(PO4)3 (KLuZrP) were prepared using the flux technique. Original synthetic procedure has been examined for the flux growth of the complex phosphates containing zirconium and lanthanide. Both compounds have been synthesized in the complex melts containing at the same time potassium phosphates and transition metal fluorides. The structures were solved from the single crystal (KNdZrP) and powder (KLuZrP) X‐ray diffraction data. Both compounds are isotypic to langbeinite mineral and crystallize in cubic system (sp. gr. P213) with the cell parameters a = 10.3228(2) and a = 10.29668(5) Å respectively. The rigid framework is built up from the isolated [MO6] octahedra and [PO4] tetrahedra interlinked via vertices. The potassium cations are located in the large closed cavities of the framework. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
5.
Crystalline hydrogen selenate-phosphates M 2H3(SeO4)(PO4) [M = Rb (I) or K (II)] and M 4H5(SeO4)3(PO4) [M = K (III) or Na (IV)] were obtained by reactions of Rb, K, and Na carbonates with mixtures of selenic and phosphoric acid solutions. The X-ray structure study of single crystals revealed that I and II are isostructural (sp. gr. Pn). In these structures, SeO4 and H3PO4 tetrahedra are linked by hydrogen bonds to form corrugated layers. Structures III and IV (sp. gr. $P\bar 1$ ) have similar arrangements of non-hydrogen atoms but different hydrogen-bond systems. In III = K4(HSeO4)2{H[H(Se,P)O4]2}, the HSeO4 groups branch from the infinite anionic {H[H(Se,P)O4]2} chains. In IV = Na4[H(SeO4)2]{H[H1.5(Se, P)O4]2}, the anionic {H[H1.5(Se,P)O4]2} chains are crosslinked by hydrogen bonds formed by the [H(SeO4)2] dimers. 相似文献
6.
The crystal structure of a new synthetic potassium gallophosphate K3Ga2(PO4)3 grown from a solution in the melt of a mixture of GaPO4 and K2MoO4 is determined using X-ray diffraction (Bruker Smart diffractometer, 2θmax= 56.6°, R = 0.044 for 2931 reflections, T = 100 K). The main crystal data are as follows: a = 8.661(2) Å, b = 17.002(4) Å, c = 8.386(2) Å, space group Pna21, Z= 4, and ρcalcd = 2.91 g/cm3. The synthesized crystals represent the third phase in the structure type previously established for the K3Al2[(As,P)O4]3 compound. It is shown that the structure consists of a three-dimensional anionic microporous tetrahedral framework of the mixed type, which is formed by PO4 and GaO4 tetrahedra shared by vertices. Large-sized cations K+ occupy channels of the zeolite-like framework. The crystal chemical features of the formation of structure types of compounds with mixed frameworks described by the general formula A 3 + M 2 3+ (TO4)3 (where A = K, Rb, (NH4), Tl; M = Al, Ga, Fe, Sc, Yb; T = P, As) are analyzed. 相似文献
7.
Zhong De‐Gao Teng Bing Wang Shu‐Hua Jiang Xue‐Jun Li Ming He Lin‐Xiang Huang Wan‐Xia 《Crystal Research and Technology》2009,44(9):925-929
Mixed crystals of potassium dihydrogen phosphate and ammonium dihydrogen phosphate were grown onto point seeds by the method of temperature reduction. It was found that the regeneration process of z‐cut point seeds became more and more difficult with increasing KH2PO4 concentration in the solution mixture. The interior stress and cracking of the mixed crystals were analyzed by synchrotron X‐ray topography. Large numbers of stress stripes were found at the seed and sectors boundaries. The lattice parameters of the pyramid and prismatic sectors of the prepared mixed crystal were calculated according to the X‐ray diffraction patterns. With solution containing 8 mol % KH2PO4, the lattice volumes of the prismatic sector of the mixed crystal were 1.3% larger than that of the pyramid sector of the crystal. Chemical etching revealed microcracks with length of hundreds of microns in the mixed crystals, which tended to spread and led to crystal cracking. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
8.
A new complex phosphate Li5Cu2Al(PO4)4 has been obtained by the flux method in the Cs-Li-Cu-V-P-O system. Its crystal structure has been determined by X-ray diffraction (R 1 = 2.74%) to be as follows: sp. gr. $P\bar 1$ , a = 4.860(5) Å, b = 7.788(5) Å, c = 8.324(5) Å, α = 69.542(5)°, β = 90.016(5)°, γ = 75.318(5)°, Z = 1, and V = 284.2(4) Å3. The compound under study has a dense structure and a three-dimensional framework build up of [LiO5], [AlO6], [Cu/LiO5], and [CuO4] polyhedra and [PO4] tetrahedra. A comparative crystal-chemical analysis of two isotypic compounds with a general formula Li5Cu2 M(PO4)4 (M = Fe, Al) has been performed. Topological relations between the Na2Mg5(PO4)4 and Li5Cu2 M(PO4)4 crystal structures, which are characterized by different cationic compositions, are revealed. 相似文献
9.
V. V. Grebenev I. P. Makarova D. A. Ksenofontov V. A. Komornikov E. V. Dmitricheva 《Crystallography Reports》2013,58(6):894-898
The symmetry (sp. gr.I $\bar 4$ 3d) and lattice parameters have been determined for the first time for Cs5(H2SO4)2(H2PO4)3 crystals in the temperature range from 172 to 390 K. The thermal and optical properties of crystals, as well as their conductivity, have been investigated at elevated temperatures. It is shown that a crystal heated to T = 365 K undergoes a phase transition with symmetry lowering to the tetragonal phase (with the parameters a = 4.965(1) Å and c = 5.016(1) Å), while at T ≈ 390 K a phase transition to the cubic phase is presumably observed. With a decrease in temperature, a phase transition without a change in symmetry occurs at T = 240 K. 相似文献
10.
采用新配方水热合成了层状结构钒磷酸盐(H2 NC4 H8 NH2)0.5[(VO)(PO4)],用ICP、TG-DTA、单晶XRD和动态XRD对合成物进行了表征.结果表明,该化合物有机模板的开始分解温度,在空气气氛中为343℃,在氮气气氛中为376℃.有机模板的分解逃逸导致了结构的破坏.随着温度的升高结构发生重组,约760 ℃时形成(VO)2P2O7;温度继续升高,(VO)2P2O7进一步氧化,形成钒磷氧化物新物相.与结构相似化合物(H3 NCH2 CH2 NH3)[(VO)(PO4)]的热稳定性比较表明,有机模板的热稳定性及其与无机骨架结合的牢固性影响化合物的热行为. 相似文献
11.
The ethylenediammonium bis tetraiodobismuthate(III) tetrahydrate salt is monoclinic with the following unit cell dimensions:a=7.476(3)Å,b=13.194(3)Å,c=13.916(9)Å, β=95.22(6)°, space groupP21 lc withZ=2. The structure consists of disordered ethylenediammonium cations, water molecules and polynuclear anions in which slightly distored [BiI6]3? octahedra sharingcis edges are interconnected into chains. The [BiI4]? anions are connected through O(W2)?H...I hydrogen bonds, so that infinite two dimensional chains parallel to thea axis with anionic period [BiI4(H2O)]? are formed in the structure. These chains are themselves interconnected by means of the O?H...I and N...O(I) bonds originating respectively from the water molecules and the ethylenediammonium entities, forming a three-dimensional network. 相似文献
12.
The investigations on the formation of mixed crystals of ammonium dihydrogen orthophosphate (ADP) and potassium dihydrogen orthophosphate (KDP) i.e. potassium ammonium dihydrogen phosphate, K1‐x(NH4)xH2PO4 have been presented in this paper. Pure and mixed crystals of ADP and KDP have been grown by slow evaporation technique from the supersaturated solution at an ambient temperature 26±1 °C for ammonium concentration x in the range 0.0 ≤ x ≤ 1.0 in the case of mixed crystals. Crystal compositions were determined by flame atomic absorption spectroscopy and chemical analysis. The results of the X‐ray analysis of the grown crystals are also reported. Thermogravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study the kinetic process of dehydration and the high temperature phase behaviour. DTA showed the distinct thermal events attributed to dehydration of ADP, KDP and K1‐x(NH4)xH2PO4. The results of thermal analysis and chemical analysis are consistent with each other. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
13.
Polyphosphates of the compositions LiPO3, Li4H(PO3)5, and LiMn(PO3)3 were prepared by the reactions of Li2CO3 and MnO2 with melts of polyphosphoric acids at 240–350°C, and their crystal structures were established. The unit-cell parameters are a = 13.074 Å, b = 5.4068 Å, c = 16.452 Å, β = 99.00°, sp. gr. P2/n; a = 6.6434 Å, b = 7.253 Å, c = 11.399 Å, α = 72.60°, β = 83.36°, γ = 85.32°, sp. gr.; $P\bar 1$ ; a = 8.364 Å, b = 8.561 Å, c = 8.6600 Å, sp. gr. P212121, respectively. The influence of cations on the structures of the compounds is discussed. 相似文献
14.
A terbium complex associating two ligands, oxalate and glutarate, was prepared under hydrothermal conditions at 200°C by treating an aqueous suspension of terbium oxalate decahydrate with glutaric acid and guanidinium carbonate. Its structure was solved by X-ray diffraction on a single crystal. It crystallizes in the monoclinic space group P21 with lattice constants, a = 9.514(1) Å, b = 9.0681(8) Å, c = 19.702(2) Å, and = 97.90(1)°. The terbium atoms and the oxalate ligands build dense chains which are connected by one side of the carboxylic group of some glutarate ligands, thus forming a sheet at the c level 0 and 1/2. These sheets are bridged by glutarate groups. The terbium atoms are ninefold coordinate with nine oxygen atoms of the ligands or with one water molecule and eight oxygen atoms of the ligands. Each polyhedron of the terbium atoms share one edge and one face of oxygen atoms with the two neighboring ones. The oxalate ligands are bischelating and bismonodentate. The coordination scheme of glutarate differs: either they are bismonodentate from one side and chelating and monodentate from the other side or they are chelating and monodentate from both sides. 相似文献
15.
Roger D. Willett Ashwani Vij Joseph M. Imhof David A. Cleary 《Journal of chemical crystallography》2000,30(6):405-410
[Na4(H2O)14]SnS4 is obtained by the reaction of Na2S·9H2O with SnCl4·5H2O in aqueous solution at 21°C. It crystallizes in the space group Cc with a = 8.621(2) Å, b = 23.543(5) Å, c = 11.358(2) Å, = 110.58(3)° and V = 2158.2 Å3 with Z = 2. Refinement of 3826 unique reflections from a racemically twinned crystal yielded a final value of R1 = 0.0464 (|F| > 4) and wR2 = 0.104 and a goodness of fit of 1.125. The structure consists of a Na+/H2O network supporting the tetrahedral SnS4
4– anions. Water molecules or sulfide ions octahedrally coordinate each of the four crystallographically independent Na+ ions. The dominant feature of the structure is the existence of zigzag chains of edgeshared Na octahedra. These chains are tied together into a three-dimensional network by bridging Na(H2O)6 octahedra and individual H2O molecules. 相似文献
16.
E. V. Dmitricheva I. P. Makarova V. V. Grebenev V. V. Dolbinina I. A. Verin 《Crystallography Reports》2014,59(3):344-352
To elucidate the effect of isomorphic substitution on the kinetics of phase transitions, single crystals of (K x (NH4)1?x ) m H n (SO4)(m + n)/2 · yH2O solid solutions are grown from the K3H(SO4)2-(NH4)3H(SO4)2-H2O system, whose end members are known to undergo superprotonic phase transitions of fundamentally different kinetics. The chemical composition of the single crystals grown is determined by energy dispersive X-ray microanalysis. The thermal and optical behavior of (K,NH4)9H7(SO4)8 · H2O single crystals is studied in the temperature range 295–420 K and the crystal structure at 295 K is determined. A comparison of the results of the studies with data for crystal K9H7(SO4)8 · H2O published earlier shows that the substitution of ammonium for potassium atoms lowers the temperature of the structural phase transition by 8 K. 相似文献
17.
L. F. Malakhova A. E. Voloshin C. C. Wilson E. B. Rudneva N. G. Furmanova V. I. Simonov 《Crystallography Reports》2003,48(1):29-34
The structures of two crystalline specimens cut out from the pyramidal and prismatic growth sectors of a K(H0.052D0.948)2PO4 single crystal have been studied by diffuse neutron scattering and precision diffuse X-ray scattering. Diffuse scattering is concentrated in the vicinity of the Bragg reflections and is practically the same in specimens cut out from different growth sectors of a single crystal. X-ray diffraction analysis using the extinction parameters provided the establishment of a higher perfection of the specimen cut out from the prismatic growth sector. The precision X-ray studies revealed different configurations of hydrogen bonds in the specimens. 相似文献
18.
From an aqueous mixture of 1,2,4,5-benzenetetracarboxylic acid, C6H2(CO2H)4, and KF we grew crystals first of KHF2 then of the title compound. An X-ray crystallographic determination of this compound shows a network of C6H2(CO
2
–
)4 units linked through hydrogen bonds to water molecules. This is the first reported structure of a benzenecarboxylate anion. Two carboxylate groups are coplanar with the benzene ring, whereas the other two are perpendicular to it. 相似文献
19.
20.
New sodium iron orthophosphate NaFe 4 2+ Fe 3 3+ [PO4]6 was synthesized by the hydrothermal method. The crystal structure (sp. gr. $P\bar 1$ ) was established by the heavy-atom method, with the exact chemical formula of the compound being unknown; R hkl = 0.0492, R whkl = 0.0544, S = 0.52. The new compound is analogous to iron phosphate Fe 3 2+ Fe 4 3+ [PO4]6 studied earlier. However, these two compounds differ in the Fe2+ and Fe3+ contents, because Na+ ions in the new compound are located at the centers of symmetry not occupied earlier. 相似文献