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1.
The crystallization conditions for the NaH2PO4, NaH2PO4 · H2O, and NaH2PO4 · 2H2O solid phases have been established from the analysis of the phase diagram of solubility of the ternary Na2O-P2O5-H2O system in the temperature range from 0 to 100°C. Based on these data, the methods for growing sodium dihydrogenphosphate
single crystals of the above compositions are developed. The initial components for preparing mother solutions were H3PO4 and NaOH solutions taken in certain weight ratios. For the first time, NaDP, NaDP · H2O, and NaDP · 2H2O single crystals were grown on a seed by the method of temperature decrease. The habits of the NaDP and NaDP · H2O single crystals are determined.
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Translated from Kristallografiya, Vol. 47, No. 5, 2002, pp. 937–944.
Original Russian Text Copyright ? 2002 by Soboleva, Voloshin. 相似文献
2.
S. I. Troyanov 《Crystallography Reports》2005,50(5):773-778
The crystal structures of alkali metal and ammonium bifluorides MHF2 (M = Na, NH4, or Rb) are refined using single-crystal X-ray diffraction. In all the crystals of acid fluorides studied, HF
2
t-
anions have a linear structure with F⋯F distances ranging from 2.277 to 2.281 Å. The crystal structures of the Rb5F4(HF2) · 2H2O and RbF · H2O compounds are determined. It is established that, in these structures, the O-H⋯F hydrogen bonds whose lengths are equal
to 2.55–2.57 and 2.63 Å participate in the formation of trinuclear bent anions and zigzag anionic chains, respectively.
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Translated from Kristallografiya, Vol. 50, No. 5, 2005, pp. 834–839.
Original Russian Text Copyright ? 2005 by Troyanov. 相似文献
3.
The Me
2O-P2O5-H2O solubility phase diagrams are used to determine the optimum compositions and the temperatures for growing crystals of MeH2PO4 solid phases (Me = Li, Na, K, Rb, Cs, NH4). The optimum conditions for dynamic growth of dihydrophosphates of the elements of the first group and ammonium are determined.
LiH2PO4, NaH2PO4, NaH2PO4 · 2H2O, NaH2PO4 · H2O, KH2PO4, K(H,D)2PO4, RbH2PO4, CsH2PO4, and (NH4)H2PO4 single crystals are grown on seed from aqueous solutions by the methods of temperature lowering and isothermal evaporation.
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Translated from Kristallografiya, Vol. 49, No. 4, 2004, pp. 773–777.
Original Russian Text Copyright ? 2004 by Soboleva, Voloshin. 相似文献
4.
Two phase transitions are revealed for the first time in Ag3Sc2(PO4)3 single crystals in the vicinity of the temperatures 303 and 165–180 K. It is established that the phase transition at 303
K corresponds to the well-known phase transition to the superionic state in Na3Sc2(PO4)3 single crystals in the temperature range 423–433 K, whereas the phase transition observed in the temperature range 170–180
K corresponds to the phase transition from the rhombohedral to monoclinic phase at about 320 K in the monoclinic Na3Sc2(PO4)3 single crystals. It is also established that rhombohedral Na3Sc2(PO4)3 single crystals undergo the second phase transition.
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Translated from Kristallografiya, Vol. 50, No. 1, 2005, pp. 122–126.
Original Russian Text Copyright ? 2005 by Shilov, Atovmyan, Kovalenko. 相似文献
5.
L. A. Pyankova Yu. O. Punin S. N. Bocharov A. G. Shtukenberg 《Crystallography Reports》2012,57(2):317-326
The growth kinetics and elementary growth processes on the surface of NH4Cl:Mn2+ heterogeneous crystals formed in the NH4Cl-MnCl2-H2O-CONH3 system are experimentally studied. It is found that a change in the composition of complexes in an NH4Cl crystal from Mn(NH4)2Cl4 · 2H2O to MnCl2 · 2CONH3 leads to the occurrence of a local maximum in the kinetic curve and a change in the shape of dislocation growth centers from
flat to conical. The growth kinetics of {100} faces of heterogeneous NH4Cl:Mn2+ crystals is described within the Bliznakov model using the Fowler-Guggenheim adsorption isotherm, which takes into account
the lateral interaction of adsorbed particles. 相似文献
6.
Quan-Zheng Zhang Guo-Quan Shao Gang Chen Huan Shen Guo-Hui Lu Rang Ping Peng-Fei Xie Yang Jiang Jie Zhang 《Journal of chemical crystallography》2007,37(5):369-373
A new organic-inorganic hybrid γ-octamolybdate complex, (NH4)4[(C3H7NO)2Mo8O26]·2CH3CH2OH·2H2O was synthesized from the mixture of ethanol, DMF, 4-aminobenzoic acid, (NH4)6Mo7O24·4H2O, HCl and H2O. The structure was determined by X-ray crystallography. It crystallizes in monoclinic P21/n space group with the crystal cell parameters of a = 8.8825(4), b = 21.1608(10), c = 11.1343(6) ?, β = 104.7720(10)°, V = 2023.64(17) ?3 and Z = 2. The crystal X-ray analysis shows that two DMF molecules are bound to γ-octamolybdate anion. The molecular structure
is stabilized by the complex hydrogen bonding. 相似文献
7.
L. B. Serezhkina E. V. Peresypkina A. V. Virovets M. O. Karasev 《Crystallography Reports》2010,55(1):19-23
Single crystals of the compound (NH4)3[UO2(CH3COO)3]2[UO2(CH3COO)(NCS)2(H2O)] (I) are synthesized, and their structure is investigated using X-ray diffraction. Compound I crystallizes in the monoclinic system with the unit cell parameters a = 18.3414(6) ?, b = 16.3858(7) ?, c = 12.4183(5) ?, β = 92.992(1)°, space group C2/c, Z = 4, V = 3727.1(3) ?3, and R = 0.0253. The uranium-containing structural units of crystals I are mononuclear complexes of two types with an island structure, i.e., the [UO2(CH3COO)3]− anionic complexes belonging to the crystal-chemical group (AB
301 = UO22+, B
01 = CH3COO−) of the uranyl complexes and the [UO2(CH3COO)(NCS)2(H2O)]− anionic complexes belonging to the crystal-chemical group AB
01M31 (A = UO22+, B
01 = CH3COO−, M
1 = NCS− or H2O). 相似文献
8.
L. V. Soboleva 《Crystallography Reports》2007,52(6):1104-1107
On the basis of the physicochemical analysis of the solubility phase diagrams for the Me
2SO4-NiSO4-H2O ternary systems (Me = Na, Rb, or Cs), the optimum concentration and temperature conditions for the crystallization of the Me
2Ni(SO4)2 · nH2O solid phases were found. Techniques for growth of single crystals of these binary salts have been developed. Such techniques
allow application of mother liquors containing hydrates or anhydrous sulfates of Na, Rb, Cs, and Ni as raw materials. Na2Ni(SO4)2 · 4H2O, Rb2Ni(SO4)2 · 6H2O, and Cs2Ni(SO4)2 · 6H2O single crystals (28–34) × (8–13) × (5–10) mm3 in size have been grown from aqueous solutions in the dynamic regime.
Original Russian Text ? L.V. Soboleva, 2007, published in Kristallografiya, 2007, Vol. 52, No. 6, pp. 1141–1144. 相似文献
9.
10.
In this paper the dielectric spectroscopy data of ammonium dihydrogen phosphate NH4H2PO4: porous glass composite was studied at various temperatures. It was found that the investigated material exhibits the two-power-law relaxation pattern with the low- (m) and high-frequency (n-1) exponents satisfying the relation m < 1 − n, where 0 < m, n < 1. Such a relaxation behavior belongs to the class of less typical ones and cannot be fitted by any of the well-know empirical relaxation functions. In order to explain the relation between the power-law exponents of the studied sample we utilize a new relaxation function, recently derived (Stanislavsky et al. (2010) [1]) in the framework of the relaxation diffusion scenario. 相似文献
11.
D. V. Pushkin E. V. Peresypkina L. B. Serezhkina A. V. Marukhnov A. V. Virovets 《Crystallography Reports》2011,56(3):451-455
The synthesis and X-ray diffraction analysis of K2(H5O2)[UO2(C2O4)2(HSeO3)] single crystals have been performed. This compound crystallizes in the triclinic system with the unit-cell parameters a = 6.7665(4) ?, b = 8.8850(4) ?, c = 12.3147(7) ?, α = 94.73°, β = 90.16°, γ = 92.11°, sp. gr. P[`1]P\bar 1, Z = 2, and R = 0.019. The basic structural units are island [UO2(C2O4)2(HSeO3)]3− groups, which belong to the AB
201
M
1 crystallochemical group of uranyl complexes (A = UO22+, B
01 = C2O42−, and M
1 = HSeO3−). Uraniumcontaining complexes are linked through K+ and H5O2+ ions and via a system of hydrogen bonds with the participation of oxonium hydrogen atoms in this structure. 相似文献
12.
L. F. Kirpichnikova M. Polomska A. Pietraszko V. S. Shakhmatov B. Hilczer 《Crystallography Reports》2005,50(1):108-114
X-ray diffraction measurements of mixed [(NH4)1−x
Rbx]3H(SO4)2 crystals of different compositions are performed. The characteristics of the change of the domain structure in the vicinity
of the supeprotonic-ferroelastic phase transition in crystals of different compositions are studied and compared with the
variations of the crystal structure in the course of gradual substitution of ammonium by rubidium. This phase transition is
theoretically described based on the phenomenological theory of a high-temperature phase transition.
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Translated from Kristallografiya, Vol. 50, No. 1, 2005, pp. 115–121.
Original Russian Text Copyright ? 2005 by Kirpichnikova, Polomska, Pietraszko, Shakhmatov, Hilczer. 相似文献
13.
M. S. Grigorev A. M. Fedoseev N. A. Budantseva A. A. Bessonov J. -C. Krupa 《Crystallography Reports》2004,49(4):598-602
The crystal structure of the K2[(NpO2)2(CrO4)3(H2O)] · 3H2O compound was established. The structure consists of anionic layers [(NpO2)2(CrO4)3(H2O)]
n
2n
, between which K+ ions and crystallization water molecules are located. The coordination polyhedra of Np atoms are distorted
pentagonal bipyramids. All chromate ions are bound in a tridentate-bridging fashion.
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Translated from Kristallografiya, Vol. 49, No. 4, 2004, pp. 676–680.
Original Russian Text Copyright ? 2004 by Grigor’ev, Fedoseev, Budantseva, Bessonov, Krupa. 相似文献
14.
Orthorhombic Fe5(PO4)4(OH)3·2H2O single crystalline dendritic nanostructures have been synthesized by a facile and reproducible hydrothermal method without the aid of any surfactants. The influences of synthetic parameters, such as reaction time, temperature, the amount of H2O2 solution, pH values, and types of iron precursors, on the crystal structures and morphologies of the resulting products have been investigated. The formation process of Fe5(PO4)4(OH)3·2H2O dendritic nanostructures is time dependent: amorphous FePO4·nH2O nanoparticles are formed firstly, and then Fe5(PO4)4(OH)3·2H2O dendrites are assembled via a crystallization-orientation attachment process, accompanying a color change from yellow to green. The shapes and sizes of Fe5(PO4)4(OH)3·2H2O products can be controlled by adjusting the amount of H2O2 solution, pH values, and types of iron precursors in the reaction system. 相似文献
15.
L. B. Serezhkina A. V. Vologzhanina V. V. Klepov V. N. Serezhkin 《Crystallography Reports》2011,56(1):132-135
Single crystals of PbUO2(CH3COO)4(H2O)3 have been investigated by X-ray diffraction (R = 0.029 for 3175 reflections). The structure of this compound is formed by [Pb(CH3COO)(H2O)3]+ chains, which are oriented along the [100] axis and limited by one-core complexes [UO2(CH3COO)3]−. The coordination numbers of the Pb(II) and U(VI) atoms are 8, and the coordination polyhedron of uranium is a hexagonal bipyramid whose vertices contain oxygen atoms of
three bidentate cyclic acetate groups and the uranyl group. Taking into account the different crystallographic roles of acetate
ions, the crystal-chemical formula of [PbUO2(CH3COO)4(H2O)3] chains can be written as AA′B
21
B
11(B
01)2
M
31, where A = Pb; A′ = UO22+; M
1 = H2O; and B
21, B
11, and B
01 are CH3COO− groups. 相似文献
16.
M. E. Chacón Villalba A. Navaza N. Dupont J. Marrot E. L. Varetti P. J. Aymonino 《Journal of chemical crystallography》2007,37(8):573-577
The crystal structure of [Co(NH3)5NO3](NO3)(PF6) ·1.5 H2O was studied by X-ray diffraction methods in order to obtain the unknown molecular structure of the [Co(NH3)5NO3]2+ cation . The substance crystallizes in the monoclinic system, space group C2/m, with a = 18.6231(6) ?, b = 7.8757(3) ?, c = 9.6434(3) ? and β = 95.484(2)°. An infrared and Raman study of the bromide salt was also performed and the spectra interpreted
with the aid of 14NO3/15NO3 isotopic replacement and quantum chemistry calculations.
E.L. Varetti — Member of the Carrera del Investigador Científico, CONICET, R. Argentina 相似文献
17.
The crystal structures of three Pd(II) compounds with diamine tetracarboxylates in different protonation states are determined,
namely, [Pd(H2
Cdta)] · H2O (I), [Pd(H3
EdtpCl] · 2H2O (II), and (H6
Edtp)[PdCl4] · 4H2O (III) (R
1 = 0.0230, 0.0313, and 0.0277 for 3040, 3377, and 3809 reflections with I > 2σ(I) for I–III, respectively). Crystals I and II are built of neutral complexes [Pd(H2
Cdta)] and [Pd(H3
Edtp)Cl], respectively, and crystallization water molecules. Crystal III consists of [PdCl4]2− anionic complexes, H6
Edtp
2+ cations, and water molecules. In I, one of the protonated acetate groups of the H2
Cdta
2− ligand forms a very weak additional Pd-O bond [2.968(2) Å] over the 2N + 2O coordination square. In II and III, the protonated propionate groups of the H3
Edtp
− ligand and the H6
Edtp
2+ cation are not involved in Pd coordination and the coordination squares consist of the 2N + O + Cl and 4Cl atoms, respectively.
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Translated from Kristallografiya, Vol. 48, No. 2, 2003, pp. 278–282.
Original Russian Text Copyright ? 2003 by Polyakova, Poznyak, Sergienko. 相似文献
18.
E. Sheha 《Journal of Non》2010,356(43):2282-2285
In this work, solid acid membrane consisting of poly(vinyl alcohol) (PVA), ammonium bromide (NH4Br) and sulfuric acid (SA) has been prepared by a solution casting technique method. X-ray diffraction of the (PVA)0.75(NH4Br)0.25(H2SO4)xM polymer matrix and pure (PVA)0.75(NH4Br)0.25 revealed the difference in crystallinity between them. The effect of different amounts of SA on the conductivity of the polymer electrolytes was studied. The ionic conductivity of the prepared electrolytes can reach 3.1 × 10−2 S cm−1 at room temperature. The conductivity measurements carried out at different temperatures indicate that all the films follow Arrhenius behavior and that the activation energy decreases with the increase in SA concentration. The a.c. conductivity seems to follow the universal power law. 相似文献
19.
Single crystals of rare earth (RE) selenates of the compositions Nd(HSeO4)3, Sm(HSeO4)3, and Nd2(SeO4)3 · 5H2O are synthesized and studied by X-ray diffraction analysis at T = 297 and 180 K. It is established that Nd and Sm hydrogen selenates are isostructural to one another and to the corresponding
hydrogen sulfates. Neodymium selenate pentahydrate is not isostructural to the analogous RE sulfates, although their structural
motifs are similar.
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Translated from Kristallografiya, Vol. 49, No. 5, 2004, pp. 835–840.
Original Russian Text Copyright ? 2004 by Zakharov, Troyanov, Kemnitz. 相似文献
20.
The crystal structure of a new synthetic aluminophosphate {[Rb1.94(H2O,OH)3.84](H2O)0.1}{Al4(OH)4[PO4]3} synthesized under mild hydrothermal conditions (T = 280°C, P = 100 atm) in the Rb2O-Al2O3-P2O5-H2O system is determined using X-ray diffraction (Stoe IPDS diffractometer, λMoK
α, graphite monochromator, 2θmax = 64.33°, R = 0.032 for 312 reflections). The main crystal data are as follows: a = 7.4931(6) ?, space group P
3m, Z = 1, and ρcalcd = 2.76 g/cm3. It is shown that the synthesized compound belongs to the pharmacosiderite structure type with a characteristic mixed open
microporous framework composed of octahedra and tetrahedra. A comparative crystal chemical analysis of related phases is performed,
and the chemical compositions of promising absorbents, i.e., hypothetical compounds potentially possible in the structure
type under consideration, are proposed. It is established that pharmacosiderite and rhodizite are homeotypic to each other.
Original Russian Text ? O.V. Yakubovich, W. Massa, O.V. Dimitrova, 2008, published in Kristallografiya, 2008, Vol. 53, No.
3, pp. 442–449. 相似文献