Thermodynamic properties of LiZr2(PO4)3 crystal phosphate

The temperature dependence of the heat capacity of LiZr₂(PO₄)₃ crystal phosphate is studied in an adiabatic vacuum calorimeter in the temperature range of 6 to 358 K. A phase transition caused by the transition of a low-temperature (triclinic) modification to a high-temperature (rhombohedral) modification is observed in the temperature range of 290–338 K and its standard thermodynamic characteristics are estimated and analyzed. Standard thermodynamic functions are calculated from experimental data: heat capacity, enthalpy, entropy, and Gibbs function in the range of T → 0 to 358 K. Fractal dimensionality D is calculated from the data on low-temperature (20 K ≤ T ≤ 50 K) heat capacity and the topology of the phosphate’s structure is estimated.     

The iron phosphate NaZnFe2(PO4)3

Crystals of sodium zinc diiron(III) triphosphate, NaZnFe₂(PO₄)₃, have been synthesized and structurally characterized by single‐crystal X‐ray diffraction. The compound features a new structural type built up from ZnO₆ octahedra, FeO₆ octahedra and FeO₄ tetrahedra, linked together via the corners and edges of PO₄ tetrahedra to form a three‐dimensional framework, with tunnels running along [100]. Within these tunnels, Na⁺ cations occupy a highly distorted cubic site.     

Synthese und Kristallstruktur von K2(HSO4)(H2PO4), K4(HSO4)3(H2PO4) und Na(HSO4)(H3PO4)

Synthesis and Crystal Structure of K₂(HSO₄)(H₂PO₄), K₄(HSO₄)₃(H₂PO₄), and Na(HSO₄)(H₃PO₄) Mixed hydrogen sulfate phosphates K₂(HSO₄)(H₂PO₄), K₄(HSO₄)₃(H₂PO₄) and Na(HSO₄)(H₃PO₄) were synthesized and characterized by X‐ray single crystal analysis. In case of K₂(HSO₄)(H₂PO₄) neutron powder diffraction was used additionally. For this compound an unknown supercell was found. According to X‐ray crystal structure analysis, the compounds have the following crystal data: K₂(HSO₄)(H₂PO₄) (T = 298 K), monoclinic, space group P 2₁/c, a = 11.150(4) Å, b = 7.371(2) Å, c = 9.436(3) Å, β = 92.29(3)°, V = 774.9(4) ų, Z = 4, R₁ = 0.039; K₄(HSO₄)₃(H₂PO₄) (T = 298 K), triclinic, space group P 1, a = 7.217(8) Å, b = 7.521(9) Å, c = 7.574(8) Å, α = 71.52(1)°, β = 88.28(1)°, γ = 86.20(1)°, V = 389.1(8)ų, Z = 1, R₁ = 0.031; Na(HSO₄)(H₃PO₄) (T = 298 K), monoclinic, space group P 2₁, a = 5.449(1) Å, b = 6.832(1) Å, c = 8.718(2) Å, β = 95.88(3)°, V = 322.8(1) ų, Z = 2, R₁ = 0,032. The metal atoms are coordinated by 8 or 9 oxygen atoms. The structure of K₂(HSO₄)(H₂PO₄) is characterized by hydrogen bonded chains of mixed H_nS/PO₄^– tetrahedra. In the structure of K₄(HSO₄)₃(H₂PO₄), there are dimers of H_nS/PO₄^– tetrahedra, which are further connected to chains. Additional HSO₄^– tetrahedra are linked to these chains. In the structure of Na(HSO₄)(H₃PO₄) the HSO₄^– tetrahedra and H₃PO₄ molecules form layers by hydrogen bonds.     

Synthesis,structure and NMR characterization of a new monomeric aluminophosphate [dl-Co(en)3]2[Al(HPO4)2(H1.5PO4)2(H2PO4)2](H3PO4)4 containing four different types of monophosphates

A new zero-dimensional (0D) aluminophosphate monomer [dl-Co(en)₃]₂[Al(HPO₄)₂(H_1.5PO₄)₂(H₂PO₄)₂](H₃PO₄)₄ (designated AlPO-CJ38) with Al/P ratio of 1/6 has been solvothermally prepared by using racemic cobalt complex dl-Co(en)₃Cl₃ as the template. The Al atom is octahedrally linked to six P atoms via bridging oxygen atoms, forming a unique [Al(HPO₄)₂(H_1.5PO₄)₂(H₂PO₄)₂]^6? monomer. Notably, there exists intramolecular symmetrical O?H?O bonds, which results in pseudo-4-rings stabilized by the strong H-bonding interactions. The structure is also featured by the existence of four different types of monophosphates that have been confirmed by ³¹P NMR and ¹H NMR spectra. The crystal data are as follows: AlPO-CJ38, [dl-Co(en)₃]₂[Al(HPO₄)₂(H_1.5PO₄)₂(H₂PO₄)₂](H₃PO₄)₄, M = 1476.33, monoclinic, C2/c (No. 15), a = 36.028(7) Å, b = 8.9877(18) Å, c = 16.006(3) Å, β = 100.68(3)°, U = 5093.2(18) Å³_, Z = 4, R₁ = 0.0509 (I > 2σ(I)) and wR₂ = 0.1074 (all data). CCDC number 689491.     

Environmentally Friendly Preparation of 3,4-Dihydropyrimidin-2(1H)-thiones Catalyzed by Al(H2PO4)3

An efficient, facile, simple, and green synthetic protocol for the Biginelli reaction has been developed for the preparation of 3,4-dihydropyrimidin-2(1H)-thione derivatives under thermal and microwave irradiation, solvent-free conditions, in the presence of aluminum hydrogen phosphate, Al(H₂PO₄)₃, as an environmentally friendly heterogeneous recyclable catalyst, in high to excellent yields and short reaction time. In addition, the catalyst could be easily recovered from the reaction mixture by simple filtration and reused several times without any loss of activity.     

Optical,thermal, and magnetic properties of a microporous fluorinated iron phosphate: (H3O)2[Fe4(H2O)2F4(PO4)2(HPO4)2](H2O)

The non-centrosymmetric microporous fluorinated iron phosphate, (H₃O)₂[Fe₄(H₂O)₂F₄(PO₄)₂(HPO₄)₂](H₂O), is endowed with properties. In fact, the thermogravimetric analysis study shows a mass loss evolution as a temperature function. The optical study was also examined by UV–vis absorption. The magnetic results reveal the appearance of a ferromagnetic behavior at low temperature (Tc = 11.64 K).     

Preparation of a biphasic calcium phosphate from Ca(H2PO4)2·H2O AND CaCO3

Sintered hydroxyapatite (HAp) and β-tricalcium phosphate (β-TCP) are the two most common bio-ceramics for bone substitute. Although their composition are analogous to the constituent of human hard tissue, but some disadvantages are always exist till now, such as they need a high temperature sintering process, and this would lose the functional groups for bioactivity and closed the micro- pores without any interconnections, that hamper the body fluid transportation and angiogenesis during regeneration. Furthermore, the sintered ceramics with block and fixed size is difficult to fit non-regular defect area. In this study, the mixtures of Ca(H₂PO₄)₂·H₂O and CaCO₃ were adjusted firstly, then distilled water were introduced in wet chemical method, and a biphasic ceramic of HAp/β-TCP will be obtained after drying and sintering, then the result product that prepared by wet chemical method will be the sample in this investigation. The physical properties of result powders were characterized by DTA/TG, XRD and SEM, respectively, the particle size of two bio-ceramics that after heat treatment were found under 5 μm in SEM examination. Powder type calcium phosphate ceramics with the Ca/P molar ratio of 1.67 can be as bone cement by mixing with polymeric binder, the fine particle product of the setting cement will possess micro-pores and macro-pores that after suitable heat treatment process, and this is good for fluid transportation and tissue regeneration.     

H2bipy]2[(UO2)6Zn2(PO3OH)4(PO4)4].H2O: an open-framework uranyl zinc phosphate templated by diprotonated 4,4'-bipyridyl

Under mild hydrothermal conditions, a new organically templated uranyl zinc phosphate, [H 2bipy] 2[(UO 2) 6Zn 2(PO 3OH) 4(PO 4) 4].H 2O ( UZnP-2), has been synthesized. Structural analysis reveals that UZnP-2 is constructed from UO 7 pentagonal bipyramids that are linked into edge-sharing dimers that are in turn joined together by ZnO 4 and PO 4 tetrahedra to form a three-dimensional network. Intersecting channels occur along the a, b, and c axes. These channels house the diprotonated 4,4'-bipyridyl cations and water molecules. Ion-exchange experiments demonstrate that replacement of the 4,4'-bipyridyl cations by alkali and alkaline-earth metal cations results in a rearrangement of the framework. Further characterization of UZnP-2 is provided by Raman and fluorescence spectroscopy. The latter method reveals strong emission from the uranyl moieties with characteristic fine structure.     

Vibrational analysis of Ag3(PO2NH)3, Na3(PO2NH)3 x H2O, Na3(PO2NH)3 x 4H2O,

FT IR and FT Raman spectra of Ag3(PO2NH), (Compound 1), Na3(PO2NH)3 x H2O (Compound II), Na3(PO2NH)3 x 4H2O (Compound III), [C(NH2)3]3(PO2NH)3 x H2O (Compound IV) and (NH4)4(PO2NH)4 x 4H2O (Compound V) are recorded and analyzed on the basis of the anions, cations and water molecules present in each of them. The PO2NH- anion ring in compound I is distorted due to the influence of Ag+ cation. Wide variation in the hydrogen bond lengths in compound III is indicated by the splitting of the v2 and v3 modes of vibration of water molecules. The NH4 ion in compound V occupies lower site symmetry and exhibits hindered rotation in the lattice. The correlations between the symmetric and asymmetric stretching vibrations of P-N-P bridge and the P-N-P bond angle have also been discussed.     

K3Ga2(PO4)3 and Na3Ga(PO4)2

The structures of tripotassium digallium tris(phosphate), K₃Ga₂(PO₄)₃, and trisodium gallium bis(phosphate), Na₃Ga(PO₄)₂, have different irregular one‐dimensional alkali ion‐containing channels along the a axis of the orthorhombic and triclinic unit cells, respectively. The anionic subsystems consist of vortex‐linked PO₄ tetrahedra and GaO₄ tetrahedra or GaO₅ trigonal bipyramids in the first and second structure, respectively.     

新型磷酸钒孔道结构化合物(H3NCH2CH2NH3)3- [ (VO)4(PO4)2 (HPO4)4]的水热 合成及结构表征

以有机分子乙二胺作为模板剂合成了新型磷酸钒孔道化合物(H3NCH2CH2NH3)3^-[(VO)4(PO4)2(HPO4)4,并通过X射线单晶衍射实验进行了结构表征,晶体学数据为：C2/c,a=1.8505(9)nm,b=0.7089(4)nm,c=2.3304(10)nm,β=96.43(3)°,V-3.038(3)nm^3,Z=8,R=0.067,Rw^b=0.1635,该化合物具有非常独特和规整的二维孔道骨架结构,进一步的晶体化学研究表明该化合物为一新的VPO物相。     

Synthesis,crystal structure,and magnetic properties of K4Mn3(HPO4)4(H2PO4)2

A new layered compound, K₄Mn₃(HPO₄)₄(H₂PO₄)₂ (1), has been synthesized under hydrothermal conditions. It crystallizes in the monoclinic space group P2₁/n with a = 8.874(2) Å, b = 6.554(1) Å, c = 18.075(4) Å, and β = 93.39(3)°. The structure consists of zigzag [Mn₃O₁₄]_n chains of edge-sharing MnO₆ octahedrons and MnO₇ pentagonal bi-pyramids, which form layers of formula [Mn₃(HPO₄)₄(H₂PO₄)₂]^4? in the ab plane via H₂PO₄ and HPO₄ units with vertex-sharing. Potassium ions lie between these layers. Magnetic measurements indicate Curie–Weiss behavior above 6 K for 1. A Heisenberg model, with alternating exchange interactions J₁J₁J₂… within the chain and exchange interactions J₃J₃… between the chains, is proposed to describe the magnetic behavior.     

The solid solution (Fe0.81Al0.19)(H2PO4)3 with a strong hydrogen bond

Single crystals of the solid solution iron aluminium tris(dihydrogenphosphate), (Fe_0.81Al_0.19)(H₂PO₄)₃, have been prepared under hydrothermal conditions. The compound is a new monoclinic variety (γ‐form) of iron aluminium phosphate (Fe,Al)(H₂PO₄)₃. The structure is based on a two‐dimensional framework of distorted corner‐sharing MO₆ (M = Fe, Al) polyhedra sharing corners with PO₄ tetrahedra. Strong hydrogen bonds between the OH groups of the H₂PO₄ tetrahedra and the O atoms help to consolidate the crystal structure.     

Determination of heat capacities and thermodynamic properties of Al4(OH)2(OCH3)4(H2N-BDC)3

Journal of Thermal Analysis and Calorimetry - The molar heat capacities of one–three-dimensional metal–organic frameworks Al4(OH)2(OCH3)4(H2N-BDC)3 (CAU-1) were measured by...