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1.
To elucidate the mechanism of nucleation and growth of filamentary crystals on the bipyramid faces of KH2PO4 (KDP) crystals from solution with the addition of Al(NO3)3 · 9H2O, the growth rates and transverse dimensions of the crystals were measured at various supersaturations, temperatures, and impurity concentrations. The dependences obtained can be interpreted with due regard for the competition between the intrinsic and impurity particles in the presence of Cabrera-Vermilyea stoppers.  相似文献   

2.
Abstract Single crystals of new open-framework lanthanide sulphate nitrite La(NO2)(SO4)(H2O) has been synthesized, in the presence of 2,6-diformyl-4-chlorophenol. His structure has been determined by X-ray diffraction data: the complex crystallizes in the tetragonal system, space group P43, with a = 7.0028(2) (?), b = 7.0028(2) (?), c = 11.8341(4) ?, V = 580.34(3) ?3, Z = 4, D c = 3.582 Mg m−3. The three-dimensional (3D) framework of this compound is built up by the linkages of lanthanide atoms and the oxygen atoms of the sulphate and nitrite groups. The lanthanum atom is 9-fold coordinated. The structure is unfamiliar in lanthanide chemistry and this compound represents the first example of nitrite lanthanide sulphate complex. Graphical Abstract An unfamiliar structure in lanthanide chemistry represented by the first example of nitrite lanthanide sulphate complex is described.   相似文献   

3.
The monomeric lead(II) complex, [Pb(phen)(H2O)(NO3)2] was prepared by a hydrothermal reaction of Pb(NO3)2, nitrilotriacetic acid, NaOH, 1,10-phenanthroline, and H2O. The structure was determined by X-ray crystallography. It crystallizes in monoclinic P2(1)/n space group with the crystal cell parameters of a = 6.3568(6), b = 20.2345(19), c = 11.2722(9) Å, β = 98.337(4)°, V = 1434.6(2) Å3, and Z = 4. The crystal X-ray analysis shows that the lead atom is six-coordinated by two N atoms of phen ligand, three oxygen atoms of nitrate anions and one water molecule. Owing to the presence of a lone pair of electrons of lead atom, a significant gap occurs in the coordination geometry around Pb ion. A 3D architecture is formed through the strong hydrogen bonding and π–π stacking interactions.  相似文献   

4.
Abstract  The gold(III) atom in [Au(NH2CH2CH2NH2)Cl2]NO3 is chelated by the ethylenediamine (en) ligand and the approximately square planar geometry is completed by two chloride atoms. Weak Au···O and Au···Cl contacts are noted above and below the square plane leading to a tetragonally distorted octahedron for the gold(III) center. Extensive charge-assisted hydrogen bonding of the type N–H···O leads to the formation of a 2-D array and layers are consolidated into a 3-D network via C–H···O and C–H···Cl contacts. The compound crystallizes in the orthorhombic space group Pbca with a = 10.3380(11) ?, b = 8.2105(7) ?, c = 19.625(2) ?, and Z = 8. Index Abstract  Square planar complex cations form additional Au···O and Au···Cl interactions to form a tetragonally distorted octahedron for gold. The ionic components are connected into a 2-D array via charge-assisted N–H···O hydrogen bonding interactions.   相似文献   

5.
The crystal structure of Rb2Mn3(H2O)2[P2O7]2, a new phase obtained in the form of single crystals under hydrothermal conditions in the MnCl2–Rb3PO4–H2O system, is determined by X-ray diffraction (Xcalibur-S-CCD diffractometer, R = 0.0270): a = 9.374(2), b = 8.367(2), c = 9.437(2) Å, ß = 99.12(2)°, space group P21/c, Z = 2, Dx = 3.27 g/cm3. A correlation between the unit-cell parameters and the size of cations forming the crystal structures of isostructural A2M3(H2O)2[P2O7]2 diphosphates (A = K, NH4, Rb, or Na; M = Mn, Fe, Co, or Ni) is revealed. It is shown that, due to the topological similarity, the structures of diphosphates and orthophosphates of the farringtonite structural type can undergo mutual transformations.  相似文献   

6.
The synthesis and X-ray diffraction study of compound Rb2[(UO2)2(C2O4)3], which crystallizes in the monoclinic crystal system, are performed. The unit cell parameters are as follows: a = 7.9996(6) Å, b = 8.8259(8) Å, c = 11.3220(7) Å, β = 105.394(2)°, and V = 770.7(1) Å3; space group P21/n, Z = 2, and R 1 = 0.0271. [(UO2)2(C2O4)3]2? layers belonging to the AK 0.5 02 T 11 crystal chemical group of uranyl complexes (A = UO 2 2+ , K 02 = C2O 4 2? , and T 11 = C2O 4 2? ) are uranium-containing structural units of the crystals. The layers are connected with outer-sphere rubidium cations by electrostatic interactions.  相似文献   

7.
Abstract  A new barium chlorovanadate, Ba5(V2O7)2Cl2, was isolated by a high-temperature (850 °C) reaction employing a CsCl/RbCl flux. The structure was determined by single crystal X-ray diffraction methods. This compound crystallizes in an orthorhombic crystal system, Pmmn (No. 59), with a = 11.558(2) ?, b = 15.164(3) ?, c = 10.023(2) ?, Z = 4 and V = 1756.7(6) ?3. The structure of Ba5(V2O7)2Cl2 was determined by full-matrix, least-squares methods with R 1 = 0.0398, wR 2 = 0.1069 and GOF = 1.048 for all data. This new structure can be described as a composite lattice made up of mixed covalent and ionic moities. The extended framework is orchestrated by stacked [Ba(V2O7)Cl]3− slabs that are interconnected by Ba2+ cations through Ba–O bonds to the [V2O7] units. The Ba2+ and Cl- ions form BN-type “[BaCl]” sheets with pseudo-hexagonal windows that are centered by [V2O7]4− pyrovanadate units. Graphical Abstract  The structure of a new chlorovanadate, Ba5(V2O7)2Cl2, exhibits an interesting BN-type salt lattice that consists of an extended [BaCl] sheet containing pseudo-hexagonal windows that are centered by [V2O7] pyrovanadate units.   相似文献   

8.
Crystallization of trigonal Ba3Fe2Ge4O14 and tetragonal Ba2Fe2GeO7 barium ferrogermanates is investigated in their own fluxes diluted by B2O3-BaF2 and B2O3-PbF2 mixtures, respectively. The ratios of the components at which the properties of the fluxes satisfy the requirements for controlled crystallization of these incongruently melting compounds are determined. Single crystals of Ba2Fe2GeO7 barium ferrogermanate are grown for the first time.  相似文献   

9.
The crystal structure of the new compound Rb2[Ti(VO2)3(PO4)3] obtained by hydrothermal synthesis in the RbCl-TiPO4-V2O5-B2O3-H2O system (a = 13.604(2) Å, c = 9.386(2) Å, sp. gr. P6cc, Z = 4, ρcalcd = 3.32 g/cm3) has been studied by X-ray diffraction (Xcalibur-S-CCD diffractometer, R = 0.038). It is shown that the isotypism of Rb2[Ti(VO2)3(PO4)3] and Cs2[Ti(VO2)3(PO4)3] is caused by the flexibility of a mixed anionic framework composed of phosphorus tetrahedra, vanadium five-vertex polyhedra, and titanium octahedra (bases of the crystal structures of these compounds). The topological correlations between the structures of titanium-vanadyl phosphates and benitoite and beryl silicates are analyzed.  相似文献   

10.
Compound [UO2(C5H12N2O)5](ClO4)2 is synthesized and characterized by thermogravimetry, IR spectroscopy, and X-ray diffraction. The compound crystallizes in the monoclinic crystal system; a = 15.2985(9) Å, b = 26.9676(15) Å, c = 20.6962(11) Å, β = 100.697(1)°, space group P21/c, Z = 8, and R = 0.0445. Discrete [UO2(C5H12N2O)5]2+ groups belonging to the AM 5 1 crystal chemical group of uranyl complexes (A = UO 2 2+ and M 1=C5H12N2O) are uranium-containing structural units of the crystals.  相似文献   

11.
Abstract  The structure of [Fe3O(O2CCH2OMe)6(H2O)3][FeCl4] · 2.5H2O has been determined. The three iron atoms and the μ3-oxo are coplanar. Each carboxylic ligand is bidentate and links two iron atoms in the cluster. The clusters are linked by intra-trimer hydrogen bonding to form a zigzag motif that forms sheets via hydrogen bonding involving disordered waters of hydration. The [FeCl4] anion is intercalated between the hydrogen-bonded sheets. Crystal data: space group P21/n, a = 10.276(2), b = 22.793(5), c = 17.091(3) ?, β = 96.66(3)°, V = 3976(1) ?3, Z = 4, R = 0.0837, wR 2 = 0.1836. Graphical Abstract  The structure of [Fe3O(O2CCH2OMe)6(H2O)3][FeCl4] · 2.5H2O has been determined in which the clusters are linked by intra-trimer hydrogen bonding to form a zigzag motif that forms sheets via hydrogen bonding involving disordered waters of hydration.   相似文献   

12.

Abstract  

Triethylammonium salts of O,O′-alkylene dithiophosphato like OGOPS2HNEt3, [where, G = –CH2CMe2CH2–(1), –CH2CEt2CH2–(2), –CMe2CH2CHMe–(3) and –CMe2CMe2–(4)] have been synthesized in quantitative yield by the direct reaction of P2S5 with 1,2- and 1,3-substituted glycols in presence of triethylamine, Et3N, in 1:2:2 molar stoichiometry in toluene. These have been mainly characterized by molecular weight, IR and NMR (1H, 13C and 31P) spectroscopic studies. Single crystal X-ray structure analysis of [OCH2CMe2CH2OPS2HNEt3] reveals that phosphorus atom is tetrahedrally bonded to two sulfur atoms and two oxygen atoms in the ring and the molecule exists as discrete cation and anion. The structure is stabilized by cation–anion N–H···S hydrogen bonded interactions. Antiparallel pattern of triethylammonium ion is sandwiched within the two-dimensional layers of the ring system.  相似文献   

13.
Abstract  Reaction between p-aminobenzoic acid (HpABA) and Cu(NO3)2 · 2.5H2O in basic MeOH/DMF affords green crystals of the dicopper paddlewheel complex, Cu2(pABA)4(DMF)2 · 2DMF, 1, identified by single crystal X-ray crystallography: triclinic P-1, with a = 10.3728(2) ?, b = 10.617(2) ?, c = 11.128(2) ?, α = 81.705(3)°, β = 79.984(2)°, γ = 65.965(2)° and Z = 2. The crystal structure of 1 reveals that it is the second polymorph of Cu2(pABA)4(DMF)2 · 2DMF and experiments on the stability of 1 indicate that it can be converted to Form I through desolvation followed by exposure to DMF. Graphical Abstract  Crystal structure of a polymorphic discrete dicoppertetracarboxylate is investigated for the conversion between the two forms influenced by hydrogen bonds.   相似文献   

14.
The crystal structure of synthetic manganese sodium borophosphate hydrate Na(H2O)[Mn(H2O)2(BP2O8)] was refined based on X-ray diffraction data. The compound was prepared by soft hydrothermal synthesis in the MnCl2-Na3PO4-B2O3-H2O system. The unit-cell parameters are a= 9.602(1) Å, c= 16.037(3) Å, sp. gr. P6522, Z= 6, D x = 2.57 g/cm3. The water molecules were found to be statistically distributed in the channels of the mixed anionic paraframework consisting of (BO4) and (PO4) tetrahedra and [MnO4(H2O)2] octahedra. The hydrogen atoms of the water molecules coordinated to the Mn2+ cations were located and their positional and thermal parameters were refined. The crystal-chemical features of borophosphates of the general formula A x M(H2O)2(BP2O8)(H2O) are considered.  相似文献   

15.
[(CH3)2NH2]5Cd3Cl11 crystals are grown by the method of isothermal evaporation from saturated aqueous solutions containing dimethylamine and cadmium chlorides, [(CH3)2NH2]Cl and CdCl2.5H2O. The crystal grown are studied by the X-ray diffraction method. It is established that the crystals are orthorhombic with the unit-cell parameters at room temperature a = 18.115 ± 0.004 Å, b = 11.432 ± 0.002 Å, and c = 15.821 ± 0.003 Å. The unit-cell parameters a, b, and c of the [(CH3)2NH2]5Cd3Cl11 crystals are measured as functions of temperature in the temperature range 100–320 K. The data obtained were used to determine the thermal expansion coefficients along the main crystallographic axes. The temperature curves of the unit-cell parameters and thermal expansion coefficients showed pronounced anomalies in the vicinity of the temperatures T 1 = 120, T 2 = 150, and T 3 = 180 K corresponding to the phase transitions in the [(CH3)2NH2]5Cd3Cl11 crystals. The crystals are also characterized by a pronounced anisotropy of thermal expansion.  相似文献   

16.
The unit-cell parameters of [NH2(CH3)2]MnCl3 · 2H2O crystals are determined by X-ray diffraction analysis and the velocities of longitudinal ultrasonic waves in these crystals are measured by the echo-pulse method in the temperature range 100–315 K. The coefficients of thermal expansion along the principal crystallographic axes are derived from the temperature dependences of the unit-cell parameters. The temperature dependences of the characteristics studied reveal kink anomalies at temperatures of ~125, 179, 203, 260, and 303 K. These anomalies are indicative of structural transformations in the [NH2(CH3)2]MnCl3 · 2H2O crystals, which may be related to the dynamics of dimethylammonium cations.  相似文献   

17.
The accurate X-ray diffraction study of a Sr3Ga2Ge4O14 crystal was performed based on two X-ray diffraction data sets collected on a diffractometer equipped with a CCD area detector (a = 8.2776(2), c = 5.0415(1) Å, sp. gr. P321, Z = 1, R/wR = 0.78/0.69%, 3645 independent reflections). The structure of Sr3Ga2Ge4O14 is characterized by the presence of two mixed cation sites, which is accompanied by the anharmonic motion not only of cations, but also of two oxygen atoms in general positions. The structures and electromechanical characteristics of Sr3Ga2Ge4O14 and Sr3TaGa3Si2O14 were compared. The Sr3Ga2Ge4O14 structure is characterized by a larger elongation of the Sr polyhedron along the a axis and, simultaneously, by the smaller unit-cell parameter a compared with Sr3TaGa3Si2O14, which correlates with the ratio of the piezoelectric coefficients d 11. The absence of thermally stable directions in the crystals of Sr3Ga2Ge4O14 and Sr3TaGa3Si2O14 is consistent with the absence of the anomalous temperature dependence of the dielectric constant ?33.  相似文献   

18.
The crystal structure of a newly synthesized compound Na2Ba2[B10O17(OH)2] has been determined (Syntex \(P\bar 1\) diffractometer, MoKα radiation, 1784 crystallographically nonequivalent reflections, anisotropic approximation, R = 1.7%). The parameters of the monoclinic unit cell are a = 11.455(7), b = 6.675(4), c = 9.360(7) Å, β = 93.68(5)°, Z = 2, sp. gr. C2. The structure consists of double pseudohexagonal layers built by BO4-tetrahedra and BO3-triangles forming three-membered rings of two mutually orthogonal orientations. The neighboring layers along the [001] direction are bound by Na-polyhedra and hydrogen bonds with participation of OH groups. The interlayer tunnels along the [100] direction are filled with columns of Ba-polyhedra. The crystallochemical characteristics of a number of synthetic Ba-borates (to which the structure of new decaborate is related) are considered in terms of borate building blocks singled out in the structure.  相似文献   

19.
Single crystals of Cs4(HSO4)3(H2PO4) are synthesized and studied for the first time. The new compound is found in the course of studies of the phase diagram of the CsHSO4–CsH2PO4–H2O triple system. Data on the atomic crystal structure of single-crystalline and powder specimens, as well as on structural phase transitions, are obtained.  相似文献   

20.

Abstract  

Single crystals of iron and manganese phosphate Fe6.36Mn0.64(PO3(OH))4(PO4)2 was synthesized by hydrothermal method. The compound crystallizes in the Fe7(PO4)6 structure type and is isotypic with the solid solution \textM7 - \textx \textM\textx ( \textHPO4 )4 ( \textPO4 )2 {\text{M}}_{{7 - {\text{x}}}} {\text{M}}_{\text{x}}^{\prime} \left( {{\text{HPO}}_{4} } \right)_{4} \left( {{\text{PO}}_{4} } \right)_{2} where M is Fe, Co, Mg, Mn. The compound is triclinic, P-1, a = 6.571(5), b = 7.993(3), c = 9.547(2) Ǻ, α = 103.97(1)°, β = 109.29(2)°, γ = 101.57(3)°. The structure is based on a three-dimensional framework of distorted edge-sharing MO6 and MO5 polyhedra, forming infinite chains, which are interlinked by corner-sharing with PO4 tetrahedra. The formula unit is centrosymmetric, with all atoms in general positions except for one Fe atom, which has site symmetry −1.  相似文献   

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