Synthesis of Calcium Phosphates by PO(OH)x(OBut)3−x and CaO2C2H4

In this work, an alkoxide solution route to synthesize Ca phosphates was developed. For the precursors, a CaO₂C₂H₄ solution was prepared by dissolving Ca metal powder into ethylene glycol, and a PO(OH)_x(OBut)_3–x solution was prepared by dissolving P₂O₅ inton -butanol under reflux conditions. In order to obtain a mixed solution of the two precursors, acetic acid was used as an additive. The experimental results show that (1) -2CaO · P₂O₅, -3CaO · P₂O₅, and hydroxyapatite can be easily synthesized by converting the corresponding mixed solutions to powder products in a hot plate, and calcining the as prepared products at 1100°C; (2) acetic acid behaves as a good agent for controlling the reactions between the two precursors by modifying the CaO₂C₂H₄ species in solution and decreasing the reactivity of the PO(OH)_x(OBut)_3–x species.     

Synthesis and physical and chemical characterization of Ca10−xAgx(PO4)6(OH)2−xx apatites

The synthesis of calcium-silver hydroxyapatites of composition Ca_10−xAg_x(PO₄)₆(OH)_2−xx is discussed, together with their physical and chemical properties. Samples prepared both by dry process and by double decomposition were characterized using a variety of analytical techniques (chemical analysis, X-ray diffraction, infrared spectroscopy). The lattice parameters a and c increase linearly with the amount of silver added. The increase is attributed to the preferential substitution of the silver ion in site me (I) of these apatites.     

Liquid-phase oxidation with hydrogen peroxide of benzyl alcohol and xylenes on Ca10(PO4)6(OH)2 – CaWO4

A W-containing apatite (W/HAp) catalyst was prepared following a hydrothermal synthesis route and served as a model catalyst. Crystallographic analysis indicated that the resulting material contained hydroxyapatite, Ca_10−3xW_x(PO₄)₆(OH)₂, W-hydroxyapatite, calcium tungstate, CaWO₄, and tricalcium phosphate, Ca₃(PO₄)₂. The catalyst was investigated in liquid phase oxidation of benzyl alcohol and xylenes using hydrogen peroxide as an oxidant. For comparison, commercial calcium phosphate, hydroxyapatite and CaWO₄ were tested in the same reaction. Calcium phosphate and hydroxyapatite appeared as inactive and decomposed hydrogen peroxide non-selectively. A moderate activity but low hydrogen peroxide efficiency was observed for the CaWO₄ phase. In contrast, the W/HAp catalyst showed a reasonable activity and a better hydrogen peroxide efficiency in the oxidation of benzyl alcohol and xylenes. This new W/HAp catalyst showed, after six cycles, losses of the activity below 15% compared to the fresh catalyst with no effect on the selectivity. It is noteworthy that ICP-OES analyses showed no tungsten leaching that is the main advantage of this catalyst.     

New 1D and 2D metal oxygen connectivities in Cu(II) succinato and glutarato coordination polymers: [Cu3(H2O)2(OH)2(C4H4O4)2] · 4H2O, [Cu4(H2O)2(OH)4(C4H4O4)2] · 5H2O and [Cu5(OH)6(C5H6O4)2] · 4H2O

Two Cu(II) hydroxo succinates [Cu₃(H₂O)₂(OH)₂(C₄H₄O₄)₂]?·?4H₂O (1) and [Cu₄(H₂O)₂(OH)₄(C₄H₄O₄)₂]?·?5H₂O (2) and one Cu(II) hydroxo glutarate [Cu₅(OH)₆(C₅H₆O₄)₂]?·?4H₂O (3) have been prepared and structurally characterized by single crystal X-ray diffraction methods. They feature 1D and 2D copper oxygen connectivity of elongated {CuO₆} octahedra in “4?+?1?+?1” and “4?+?2” coordination geometries. Within 1, linear trimers of three edge-sharing {CuO₆} octahedra are connected into copper oxygen chains, which are bridged by the anti conformational succinate anions to generate 2D layers with mono terminally coordinating gauche succinate anions on both sides. The layers are assembled into a 3D framework by interlayer hydrogen bonds with lattice H₂O molecules distributed in channels. Different from 1, the principal building units in 2 are linear tetramers of four edge-sharing {CuO₆} octahedra. The tetramers are condensed into copper oxygen chains and the succinate anions interlink them into a 3D framework with triangular channels filled by lattice H₂O molecules. The {CuO₆} octahedra in 3 are edge-shared to form unprecedented 2D inorganic layers with mono terminally coordinating glutarate anions on both sides. Interlayer hydrogen bonding interactions are responsible for supramolecular assembly of the layers into a 3D framework with lattice H₂O molecules in the channels. The inorganic layers in 3 can be described as hexagonal close packing of oxygen atoms with the Cu atoms in the octahedral cavities. The title compounds were further characterized by elemental analyses, IR spectra and thermal analyses.     

Molar heat capacity and thermodynamic properties of Lu(C5H9NO4)(C3H4N2)6(ClO4)3·5HClO4·10H2O

A complex of Lutetium perchloric acid coordinated with l-glutaminic acid (C₅H₉NO₄) and imidazole (C₃H₄N₂), Lu(C₅H₉NO₄)(C₃H₄N₂)₆(ClO₄)₃·5HClO₄·10H₂O was synthesized and characterized. Thermodynamic properties of the complex were studied with an adiabatic calorimeter (AC) from 80 to 390 K and differential scanning calorimetry (DSC) from 100 to 300 K. Two thermal abnormalities were discovered at 220.34 and 248.47 K, which were deduced to be phase transitions. One was interpreted as a freezing-in phenomenon of the reorientational motion of ClO₄ ^? ions and the other was attributed to the orientational order/disorder process of ClO₄ ^? ions. The low-temperature molar heat capacities were measured by AC and the thermodynamic functions [H _T  ? H _298.15] and [S _T  ? S _298.15] were derived in the temperature range from 80 to 390 K with temperature interval of 5 K. Thermal decomposition behavior of the complex was studied by thermogravimetric analysis and DSC.     

Syntheses and Structures of the Hexacoordinated Antimony Complexes: Ph3(C2H4O2)Sb⋅⋅⋅DMSO, (3-FC6H4)3(C2H4O2)Sb⋅⋅⋅DMSO,and (4-MeC6H4)3(C6H4O2)Sb⋅⋅⋅DMSO

Russian Journal of Coordination Chemistry - Complexes Ph3(C2H4O2)Sb???DMSO (I), (3-FC6H4)3(C2H4O2)Sb???DMSO (II), and...     

Coordination behavior of 1,4-diallylpiperazinium and 1-allyloxybenzotriazole toward silver(I) in the crystalline π-complexes [Ag2(C4H8N2(C3H5)2(H+)2)(H2O)2(NO3)2](NO3)2 and [Ag(C6H4N3(OC3H5)(NO3))]

Reactions of a solution of AgNO₃ in aqueous methanol with solutions of 1,4-diallylpiperazine (acidified with HNO₃ to pH = 4) and 1-allyloxybenzotriazole in ethanol gave the crystalline silver(I) π-complexes [Ag₂(C₄H₈N₂(C₃H₅)₂(H⁺)₂)(H₂O)₂(NO₃)₂](NO₃)₂ (I) and [Ag(C₆H₄N₃(OC₃H₅)(NO₃))] (II). Their crystal structures were determined by X-ray diffraction. Crystals of complexes I and II are monoclinic, space group P2₁/c; for I: a = 7.053(3)Å, b = 9.389(3)Å, c = 15.488(4)Å, β = 91.60°, V = 1025.3(6)ų, Z = 4; for II: a = 10.650(4)Å, b = 15.062(5)Å, c = 7.412(4)Å, β = 104.20(3)°, V = 1152.6(8)ų, Z = 4. In both structures, the organic components act as bidentate ligands forming with AgNO₃ 34- and 14-membered topological rings, respectively. In complex I, the nearly tetrahedral environment of the Ag(I) atom is made up of the olefinic C=C bond, the O atoms of the nitrate anions, and the water molecule. 1-Allyloxybenzotriazole in structure II causes the deformation of the coordination polyhedron of Ag into a trigonal pyramid via inclusion of the ligand N atom in its coordination sphere. The topological units of the complexes form infinite polymer layers linked by anionic NO ₃ ^? bridges. In structure I, these layers are united through a system of hydrogen bonds into a three-dimensional framework.     

Preparation and Raman spectra of Ca(NO2)2·H2O,Ca(NO2)2 and Mg(NO2)2·H2O

The above named salts have been prepared from aqueous solutions of the pure nitrates. Distinct compounds Ca(NO₂)₂·H₂O and Ca(NO₂)₂ which are free of nitrate impurity have been characterized by their Raman spectra. The hydrated salt appears to contain four crystallographically non-equivalent nitrate groups. A distinct hydrate of magnesium formulated as Mg(NO₂)₂·H₂O can also be prepared and characterized by Raman spectroscopy but this sample always contained significant nitrate impurity.     

Hydrothermal Synthesis and Crystal Structure of a New Phosphonate： {[Cu（1,10-phen）]2-（H2O3PCH2C6H4C6H4CH2PO3H）2-（HO3PCH2C6H4C6H4CH2PO3H） }n

1 INTRODUCTION Metal organophosphonates have attracted considerable attention for over three decades due to their potential or practical applications, include- ing ion exchanges[1, 2], molecular sensors[3] and optics[4, 5]. Recently, a number of porous m…     

Hydrothermal synthesis and characterization of a new organically templated three-dimensional open-framework gallium phosphate–phosphite (C6N2H18)2(C6N2H17)Ga15(OH)8(PO4)2(HPO4)12(HPO3)6·2H2O

Using H₃PO₃ as a phosphorus source and oxalic acid as a reducing agent, the first three-dimensional open-framework gallium phosphate–phosphite formula as (C₆N₂H₁₈)₂(C₆N₂H₁₇)Ga₁₅(OH)₈(PO₄)₂(HPO₄)₁₂(HPO₃)₆·2H₂O (1), has been hydrothermally synthesized in the presence of N,N,N′,N′-tetramethylenediamine (TMEDA) as a structure-directing agent. Compound 1 crystallizes in trigonal system with space group P ? 3, a = b = 19.046(3) Å, c = 8.3306(17) Å, γ = 120°, V = 2617.1(7) Å³, and Z = 1. Its 3-D network is based on alternated Ga-centered (GaO₄ tetrahedra, GaO₅ trigonal bipyramids, and GaO₆ octahedra) and P-centered (PO₄^3?, HPO₄^2?, and HPO₃^2?) units. Protonated organic amines and water molecules are located in the 12-membered ring channels.     

Bioresorbable carbonated hydroxyapatite Ca10−xNax(PO4)6−x(CO3)x(OH)2 powders for bioactive materials preparation

The purpose of this work was to find and investigate a correlation between the carbonate ion content in crystalline lattice and defect structure, and solubility of the materials; finally, to prepare the materials under study for in vitro tests. Various techniques, such as XRD, FTIR, TEM, FESEM/EDX, TG/DTA, AES (ICP), wet chemical analysis, Ca-ionometry, microvolumetric analysis of evolved CO₂, BET adsorption, were applied to determine the efficiency of carbonate substitution, and to quantify the elemental composition, as well as to characterize the structure of the carbonated hydroxyapatite and the site(s) of carbonate substitution,. It was shown that AB-type substitution prevails over other types with the carbonate content increase. According to in vitro tests, the bioactivity of the samples is correlated with the carbonate content in carbonate-doped hydroxyapatite due to accumulation of defects in carbonated hydroxyapatite nanocrystals.      

Crystal structure of [Pt3S2(P(CH2OH)3)6](PF6)(OH)·H2O

[Pt₃S₂(P(CH₂OH)₃)₆](PF₆)(OH)·H₂O (1) is obtained by a reaction of [Pt₃S₂(P(CH₂OH)₃)₆]Cl₂ with NH₄PF₆. The crystal structure of 1 was determined by a single crystal X-ray diffraction analysis (space group R{ie638-1}c, a = 12.0042(2) Å, c = 52.6879(11) Å, V = 6575.2(2), Z = 6, C₁₈H₅₇F₆O₂₀P₇Pt₃S₂, d _x = 2.385 g/cm³, T = 150 K, R ₁ = 0.044 for 2123 F ₀ > 4δ(F) until 2θ_max = 63°). The cations contain a {Pt₃(μ₃-S)₂}²⁺ core with nonbonding Pt…Pt distances of 3.1536(6) Å. The Pt atoms are in a square planar environment; the Pt-S and Pt-P bond lengths are 2.3586(16) Å and 2.260(2) Å respectively.     

Synthesis and structural characterisation of new ettringite and thaumasite type phases: Ca6[Ga(OH)6·12H2O]2(SO4)3·2H2O and Ca6[M(OH)6·12H2O]2(SO4)2(CO3)2, M = Mn,Sn

Investigations into the formation of new ettringite-type phases with a range of trivalent and tetravalent cations were carried out to further study the potential this structure type has to incorporate cations covering a range of ionic radii (0.53–0.69 Å). We report the synthesis and structural characterisation of a new ettringite-type phase, Ca₆[Ga(OH)₆·12H₂O]₂(SO₄)₃·2H₂O, which was indexed in space group P31c with the unit cell parameters a = 11.202(2) Å, c = 21.797(3) Å and two new thaumasite-type phases Ca₆[M(OH)₆·12H₂O]₂(SO₄)₂(CO₃)₂, M = Mn, Sn which were indexed in space group P6₃ with the unit cell parameters a = 11.071(5) Å, c = 21.156(8) Å and a = 11.066(1) Å, c = 22.420(1) Å respectively. These new phases show the versatility of the ettringite family of structures to tolerate a large range of cation sizes on the octahedral M site and highlights the preference of tetravalent cations to crystallise with the thaumasite structure over the ettringite structure.     

Synthesis and characterisation of MIL-43 and MIL-44, two new layered templated tetravalent phosphates: Zr(PO4)2·N2C2H10 and Ti2(PO4)2(HPO4)2·N2C2H10

Zr(PO₄)₂·N₂C₂H₁₀ or MIL-43 and Ti₂(PO₄)₂(HPO₄)₂·N₂C₂H₁₀ or MIL-44 were prepared hydrothermally (20 or 4 days, 473 or 453 K, respectively, autogenous pressure) in the presence of ethylenediamine. Their structures have been determined by single-crystal X-ray diffraction. MIL-43 crystallises in the monoclinic space group P2₁ (No. 4) with a=11.0722(1), b=10.6631(1), c=16.4642(2) Å, β=95.991(1)° and V=1933.21(3) Å³ (final agreement factors R₁(F)=0.0466, wR₂(F²)=0.1096). Due to the very poor quality of the crystal, only an approached structure of MIL-44 is given; it crystallises in the triclinic space group P1 (No. 1) with a=5.0845(4), b=6.3097(5), c=12.6111(9) Å, α=77.454(1), β=78.926(2), γ=89.986(1)° and V=387.21(5) Å³. Both solids are two-dimensional and are the ion-exchanged equivalents of the layered solids αZrP and γTiP. Inorganic sheets of MIL-43 are built up from pseudo-hexagonal arrays of ZrO₆ octahedra surrounded by PO₄ tetrahedra pointing their terminal oxygen alternatively up and down at the interlayer space. Layers of MIL-44 are made of double (TiOP) chains built from TiO₆ octahedra and PO₄ tetrahedra on which HPO₄ groups are grafted pointing towards the interlayer space. In both cases, diprotonated organic templates, located between the layers, interact with terminal phosphate groups and ensure via hydrogen bonds the stability of the structures.     

[(C6H5 NO2)Pr(H2O)4](CrMo6O24H6)·(C6H5NO2)·2.5H2O的合成与晶体结构

用常规合成方法制备了基于Anderson结构阴离子的二维层状化合物[(C6H5NO2)2Pr(H2O)4](CrMo6O24H6)·2.5H2O,通过红外光谱和X射线单晶衍射对其进行了表征.结果表明,该化合物属于单斜晶系,C2/c空间群.a=2.3442(9)nm,b=1.3291(5)nm,c=2.458(1)nm,β=103.08(1)°,V=7.460(5)nm3,R1=0.0727,wR2=0.1903.结构分析表明,[CrMo6O24H6]3-阴离子通过端氧担载一个配位的Pr3+离子形成中性的(C6H5NO2)Pr(H2O)4(CrMo6O24H6)基团,相邻的中性基团在Ot—Pr—Ot桥联下形成一维链,链与链又通过异烟酸的桥联形成二维层状结构.     

A new mixed multi-metallic calcium–cobalt-phosphotungstate with nano wheel-like polyanion: Na6Ca3[Ca2(H2O)6Co9(OH)3(H2O)6(HPO4)2(PW9O34)3]

A new 3-D wheel-like calcium–cobalt phosphotungstate, Na₆Ca₃[Ca₂(H₂O)₆Co₉(OH)₃(H₂O)₆(HPO₄)₂(PW₉O₃₄)₃], is reported and characterized by IR, UV, and single-crystal X-ray diffraction. The crystal structure consists of an infinite 3-D array of [Ca₂(H₂O)₆Co₉(OH)₃(H₂O)₆(HPO₄)₂(PW₉O₃₄)₃]^12? anions (1) connected by sodium and calcium metal cations. The novel feature is the presence of two Ca²⁺, bonded to oxygen of HPO^4? and to H₂O spanning opposite sides in the complex anion. The stability of the crystalline product and its morphology were studied by SEM-EDX and DSC techniques.     

A Raman and infrared spectroscopic study of the mineral delvauxite CaFe4(3+)(PO4,SO4)2(OH)8·4-6H2O--a 'colloidal' mineral

The mineral delvauxite CaFe(4)(3+)(PO(4),SO(4))(2)(OH)(8)·4-6H(2)O has been characterised by Raman spectroscopy and infrared spectroscopy. The mineral is associated with the minerals diadochite and destinezite. Delvauxite appears to vary in crystallinity from amorphous to semi-crystalline. The mineral is often X-ray non-diffracting. The minerals are found in soils and may be described as 'colloidal' minerals. Vibrational spectroscopy enables determination of the molecular structure of delvauxite. Bands are assigned to phosphate and sulphate stretching and bending modes. Two symmetric stretching modes for both the phosphate and sulphate symmetric stretching modes support the concept of non-equivalent phosphate and sulphate units in the mineral structure. Multiple water bending and stretching modes imply that non-equivalent water molecules in the structure exist with different hydrogen bond strengths.     

Crystal structure of Μ2, η2, Σ2-nitrato-η2, Σ2-nitrato-bis(1-ethyltetrazole-N4)copper(II) Cu(C3H6N4)2(NO3)2 = [Cu(C3H6N4)2(NO3)(NO3)2/2]∞

The complex compound of copper(II) nitrate with 1ethyltetrazole (ettz), Cu( C₃H₆N₄)₂(NO₃)(NO₃)_2/2] is studied by Xray diffraction analysis (“Syntex P2₁” automatic diffractometer, CuK_a radiation, graphite monochromator, 6/26 scan mode with V_min = 3.91 deg/min, the total number of data collected 3544 l_hkb including 3141 nonextinct l_hkl > 0, a correction for absorption (Μ = 25.08 cm^-1) applied by integrating over the crystal faces). The parameters of the orthorhombic unit cell (space group Pccn) are a = 15.436(3), b = 20.198(5), c = 19.587(3) Å, V_cell = 6107(2) Å^{3, Z} = 16, d_calc = 1.670 g/cm³. The two crystallographically independent copper atoms have a distorted octahedral environment (coordination node is CuN₂O₄), coordination number (CN) is 6 = 4 + t2. In the equatorial plane, two nitrogen atoms of ettz and two oxygen atoms of NO ₃ ^? groups are trans to each other; Cu-N = 1.983(8), C-O_{NO 3} ^? = 1.978(7) Å (average). The nitrato groups fulfill chelate and bridging functions, complementing the coordination polyhedra of the copper atoms to distorted octahedra, where Cu-O_{NO 3} ^? = 2.517(7) Å (average). The compound has a chain structure; the chains stretching along [001] are packed pairwise according to the hexagonal law.     

Investigations in the systems Sr–As–O–X (X = H,Cl): Preparation and crystal structure refinements of the anhydrous arsenates(V) Sr3(AsO4)2, Sr2As2O7, α- and β-SrAs2O6, and of the apatite-type phases Sr5(AsO4)3OH and Sr5(AsO4)3Cl

The previously uninvestigated atomic arrangements of six strontium arsenate(V) phases in the systems Sr-As-O-X (X = H, Cl) have been determined. Single crystals of Sr₃(AsO₄)₂ and Sr₅(AsO₄)₃Cl were grown from a borate and NaCl melt, respectively, whereas single crystals of α- and β-SrAs₂O₆ and of Sr₅-(AsO₄)₃OH were obtained under hydrothermal conditions. Microcrystalline samples of Sr₂As₂O₇ were prepared by solid-state reaction of As₂O₅ with SrCO₃ and, alternatively, by thermolysis of SrHAsO₄. Crystal structure determinations based on powder X-ray diffraction data using the Rietveld method (Sr₂As₂O₇), and from single-crystal X-ray diffraction data (all other phases) revealed isotypism with known structure types (except β-SrAs₂O₆ which represents a new structure type). Sr₃(AsO₄)₂ crystallizes in the K₂Pb(SO₄)₂ structure type; Sr₂As₂O₇ is isotypic with the high-temperature polymorphs of Ca₂P₂O₇ and Sr₂V₂O₇, but itself shows no polymorphism; Sr₅(AsO₄)₃OH and Sr₅(AsO₄)₃Cl crystallize with the hydroxylapatite and chloroapatite structure, respectively; SrAs₂O₆ is dimorphic. Like all other known M^IIAs₂O₆ metaarsenates (M = Mn, Co, Ni, Sr, Pd, Cd, Hg, Pb), the α-polymorph crystallizes in the PbSb₂O₆ structure type, whereas the novel β-polymorph is the first example of a M^IIAs₂O₆ superstructure with a doubled c-axis. Additional analytical methods using Raman spectroscopy and thermal analyses support the results of the X-ray structure work.     

Synthesis and Characterization of a Reduced Molybdenum(Ⅴ) Phosphate, (H3dien)2(H2dien)2[NaMo12O24(OH)6-(H2PO4)(HPO4)5(PO4)2]·nH2O(n= 10.92)

A new reduced molybdenum(Ⅴ) phosphate (H3dien)2(H2dien)2[NaMo12O24 (OH)6 (H2PO4)(HPO4)5(PO4)2]·nH2O(n= 10.92,dien = diethylenetriamine) has been synthesized under hydrothermal conditions and characterized by elemental analyses, IR and X-ray diffraction. C16H96.84MO12N12NaO72.92P8 (Mr = 3046.73) crystallizes in the monoclinic system, space group P21/c with a = 13.3575(18), b = 21.907(3), c = 15.654(2) A, β= 110.22(2)°, V= 4298.4(10) (A)3, Dc = 2.354 g/cm3, Z = 2, μ(MoKα) = 1.966 mm-1, F(000) = 2990.4, the final R = 0.0357 and wR = 0.1086 for 8739 observed reflections with Ⅰ> 2σ(Ⅰ). It consists of sandwich-shaped cluster anions [Na{Mo6P4}2]10- held together into a three-dimensional supramolecular framework through intermolecular hydrogen-bonding contacts. A probe reaction of the oxidation of acetaldehyde with H2O2 showed that this compound has high catalytic activity in the reaction.