A New Type of Anionic Framework in Microporous Potassium Iron(II) Phosphate K[Fe(PO4)]

A new iron(II) orthophosphate K[Fe(PO₄)] has been obtained by hydrothermal synthesis and its crystal structure was determined by single‐crystal X‐ray diffraction: space group P2₁/n, Z = 8, a = 9.6199(10), b = 8.6756(8), c = 10.8996(13) Å, β = 115.577(8)° at 193 K, R = 0.023. Fe^II shows coordination numbers (CN) 4 (distorted tetrahedral) and CN 5 (distorted trigonal bipyramidal). The [FeO₄] and [FeO₅] units form together with the [PO₄] tetrahedra a microporous 3D para‐framework with open channels along the a and b directions. The potassium ions positioned in the channels show CN 7 and 8. The structural relations within the morphotropic row of non‐isotypic K[M(PO₄)] structures (M = Zn, Ni, Mn, Fe) are discussed on the basis of common basic structural units.     

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.     

FeII2(PO4)(OH), a synthetic analogue of wolfeite

This paper reports the hydrothermal synthesis and crystal structure refinement of diiron(II) phosphate hydroxide, Fe^II₂(PO₄)(OH), obtained at 1063 K and 2.5 GPa. This phosphate is the synthetic analogue of the mineral wolfeite, and has a crystal structure topologically identical to those of minerals of the triplite–triploidite group. The complex framework contains edge‐ and corner‐sharing FeO₄(OH) and FeO₄(OH)₂ polyhedra, linked via corner‐sharing to the PO₄ tetrahedra (average P—O distances are between 1.537 and 1.544 Å). Four five‐coordinated Fe sites are at the centers of distorted trigonal bipyramids (average Fe—O distances are between 2.070 and 2.105 Å), whereas the coordination environments of the remaining Fe sites are distorted octahedra (average Fe—O distances are between 2.146 and 2.180 Å). The Fe—O distances are similar to those observed in natural Mg‐rich wolfeite, except for two Fe—O bond distances, which are significantly longer in synthetic Fe²⁺₂(PO₄)(OH).     

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 and crystal structure of two fluorophosphated compounds with different infinite sheets: Sr2Ga(HPO4)(PO4)F2 and Sr2Fe2(HPO4)(PO4)2F2

New compounds, Sr₂Ga(HPO₄)(PO₄)F₂ and Sr₂Fe₂(HPO₄)(PO₄)₂F₂, have been prepared by hydrothermal synthesis (700°C, 180 MPa, 24 h) and characterized by single-crystal X-ray diffraction. Sr₂Ga(HPO₄)(PO₄)F₂ crystallizes in the monoclinic space group P2₁/n with a = 8.257(1) Å, b = 7.205(1) Å, c = 13.596(2) Å, β = 108.02(1)°, V = 769.2(2) ų and Z = 4 and Sr₂Fe₂(HPO₄)(PO₄)₂F₂ in the triclinic space group P2₁/n with a = 8.072(1) Å, b = 8.794(1) Å, c = 8.885(1) Å, α = 102.46(1)°, β = 115.95(1)°, γ = 89.95(1)°, V = 550.6(1) ų and Z = 2. Structures are both based on different sheets involving corner-linkage between octahedra and tetrahedra. The sheets are linked by Sr²⁺ cations. Structural relationships exist between the descloizite mineral and the title compounds.     

Synthesis,Crystal Structure and Characterization of the Copper Iron Phosphate Cu8Fe2O5(PO4)4

The system CuO‐Fe₂O₃‐P₂O₅ has been investigated by means of the solid state reaction between CuO, Fe₂O₃ and (NH₄)₂HPO₄ in quartz crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, IR spectroscopy and TG/DTA. Single crystals of a new quaternary phase Cu₈Fe₂P₄O₂₁ were achieved by cooling from the melt of the compound in a sealed, evacuated quartz ampoule. Cu₈Fe₂O₅(PO₄)₄ crystallizes in the monoclinic space group C2/m (No 12) with a = 15.9733(8) Å, b = 5.9438(3) Å, c = 9.5530(5) Å, β = 113.76(1)°, Z = 2. The three‐dimensional framework consists of [FeO₆] octahedra, three different [CuO₅] polyhedra and [PO₄] tetrahedra. Cu₈Fe₂P₄O₂₁ exhibits an incongruently melting point at 945 °C.     

Synthesis and crystal structure of the gallium-containing montebrasite analogue LiGa(OH)PO4

Gallium lithium hydroxyphosphate LiGa(OH)PO₄ was prepared under mild hydrothermal conditions (T = 160°C, τ = 48 h) and characterized (IR spectroscopy, chemical and thermal analysis). LiGa(OH)PO₄ was found to be structurally similar to the ambligonite family phases. The crystal structure was refined by the Rietveld method (space group $P\bar 1$ , Z = 2): a = 5.0853(1) Å, b = 5.2973(1) Å, c = 7.3006(1) Å, α = 67.830(1)°, β = 67.839(1)°, γ = 82.027(1)°, R _p = 0.0519, R _wp = 0.0765. A zero SHG signal confirmed a centrosymmetric structure of the compound. The structure is represented by a mixed {Ga(OH)[PO₄]} _3∞ ^? framework composed of the PO₄ tetrahedra and GaO₄(OH)₂ octahedra. The framework contains hexagonal channels running in the [100] and [010] directions. The basic element of the framework is a linear chain of GaO₄(OH)₂ octahedra sharing trans OH vertices. The Li⁺ ions reside in the framework voids.     

Synthesis and Crystal Structure of KCuGd2S4: A Threedimensional Framework with Isolated Channels

The reaction of K₂S₅, Cu, Gd, and S in a 2 : 1 : 2 : 4 molar ratio at 450 °C yields yellow-orange needle-like cuboids of the new quaternary compound KCuGd₂S₄. The crystal structure represents a novel three-dimensional structure type of quaternary rare earth chalcogenides with alkali metal. The compound crystallizes in the orthorhombic space group Cmcm (No. 63) with a = 3.9921(1) Å, b = 13.523(3) Å, c = 13.802(3) Å, V = 745.1(3) ų, Z = 4. In the structure GdS₆ octahedra and CuS₄ tetrahedra are joined by common edges and corners forming corrugated layers parallel to (010). The GdS₆ octahedra are connected via common edges in the third dimension thus leading to the formation of a three-dimensional tunnel structure. The potassium cations are confined within the pentagonal shaped channels and are surrounded by eight sulfide anions each.     

Synthesis and structure of NH4CoPO46H2O

NH₄CoPO₄6H₂O has been synthesized from CoSO₄7H₂O and (NH₄)₂HPO₄ solutions at a pH controlled by an aqueous ammonia solution. The structure of NH₄CoPO₄6H₂O was determined by Rietveld refinement of X-ray laboratory powder diffraction data [s.g. Pmn2₁, with a=6.9403(2) Å, b=6.1457(2) Å, c=11.2190(1) Å, V=478.53 ų, Z=2, and Vat-no-H=18.4 ų/at]. The final R-factors were R_WP=14.2 %, R_F=8.0 %. The framework has isolated Co(OH₂)₆²⁺ octahedra linked to regular PO₄³⁻ and NH₄⁺ tetrahedra by electrostatic interactions and hydrogen bonds. IR data and the thermal behaviour of this compound are given and discussed on the basis of its crystal structure.     

Das erste Vanadium(III)‐Borophosphat: Darstellung und Kristallstruktur von CsV3(H2O)2[B2P4O16(OH)4]

The First Vanadium(III) Borophosphate: Synthesis and Crystal Structure of CsV₃(H₂O)₂[B₂P₄O₁₆(OH)₄] CsV₃(H₂O)₂[B₂P₄O₁₆(OH)₄] was prepared under mild hydrothermal conditions (T = 165 °C) from mixtures of CsOH_(aq), VCl₃, H₃BO₃, and H₃PO₄ (molar ratio 1 : 1 : 1 : 2). The crystal structure was determined by X‐ray single crystal methods (monoclinic; space group C2/m, No. 12): a = 958.82(15) pm, b = 1840.8(4) pm, c = 503.49(3) pm; β = 110.675(4)°; Z = 2. The anionic partial structure contains oligomeric units [BP₂O₈(OH)₂]^5–, which are built up by a central BO₂(OH)₂ tetrahedron and two PO₄ tetrahedra sharing common corners. V^III is octahedrally coordinated by oxygen of adjacent phosphate tetrahedra and OH groups of borate tetrahedra as well as oxygen of phosphate tetrahedra and H₂O molecules, respectively (coordination octahedra VO₄(OH)₂ and VO₄(H₂O)₂). The oxidation state +3 for vanadium was confirmed by measurements of the magnetic susceptibility. The trimeric borophosphate groups are connected via vanadium centres to form layers with octahedra‐tetrahedra ring systems, which are likewise linked via V^III‐coordination octahedra. Overall, a three‐dimensional framework constructed from VO₄(OH)₂ and VO₄(H₂O)₂ octahedra as well as BO₂(OH)₂ and PO₄ tetrahedra results. The structure contains channels running along [001], which are occupied by Cs⁺ in a distorted octahedral coordination (CsO₄(H₂O)₂).     

The crystal structure of K2[Cu3ZnF(PO4)3], a new mixed zinc copper phosphate

The title compound has been prepared by hydrothermal synthesis and its crystal structure was determined by single crystal X-ray diffraction: space group P2₁/m, a = 4.8890(2), b = 14.3857(5), c = 7.9017(3) Å, β = 90.134(4)°, wR₂ = 0.123, R = 0.045. Cu²⁺ has two different coordination polyhedra: an elongated square pyramidal [CuFO₄] and square planar [CuO₄] coordination in a 2:1 ratio. Edge-sharing double-pyramids and [CuO₄] squares form zig-zag chains interconnected by [ZnO₄] and [PO₄] tetrahedra to form an open anionic framework structure whose channels are occupied by the K⁺ ions.     

MII(C4H12N2)[B2P3O12(OH)] (MII = Co,Zn): Synthesis and Crystal Structure of Novel Open Framework Borophosphates

Two novel borophosphates, M^II(C₄H₁₂N₂)[B₂P₃O₁₂(OH)] (M^II = Co, Zn), exhibiting open frameworks, have been synthesized by hydrothermal reactions (T = 165 °C). The crystal structures of the isotypic compounds have been determined both at 293 K (orthorhombic, Ima2 (no. 46), Z = 4; M^II = Co: a = 12.4635(4) Å, b = 9.4021(4) Å, c = 11.4513(5) Å, V = 1341.90 ų, R₁ = 0.0202, wR₂ = 0.0452, 2225 observed reflections with I > 2σ(I); M^II = Zn: a = 12.4110(9) Å, b = 9.4550(5) Å, c = 11.4592(4) Å, V = 1344.69 ų, R₁ = 0.0621, wR₂ = 0.0926, 1497 observed reflections with I > 2σ(I)). Distorted CoO₆‐octahedra and ZnO₅‐square‐pyramids, respectively, share common oxygen‐corners with BO₄‐, PO₄‐ and (HO)PO₃‐tetrahedra. The tetrahedral groups are linked via common corners to form infinite loop‐branched borophosphate chains [B₂P₃O₁₂(OH)^4–]. The open framework of M^II‐coordination polyhedra and tetrahedral borophosphate chains contains a three‐dimensional system of interconnected structural channels running along [100], [011] and [011], respectively, which are occupied by di‐protonated piperazinium ions.     

A synthetic iron phosphate mineral, spheniscidite, [NH4]+[Fe2(OH)(H2O)(PO4)2]?H2O, exhibiting reversible dehydration

Spheniscidite, a synthetic iron phosphate mineral has been synthesized by hydrothermal methods. The material is isotypic with another iron phosphate mineral, leucophosphite. Spheniscidite crystallizes in the monoclinic spacegroupP2₁/n. (a=9·845(1),b=9·771(3),c=9·897(1),β=102·9°,V=928·5(1),Z=4,M=372·2,d _calc=2·02 g cm⁻³ andR=0·02). The structure consists of a network of FeO₆ octahedra vertex-linked with PO₄ tetrahedra forming 8-membered one-dimensional channels in which the NH₄ ⁺ ions and H₂O molecules are located. The material exhibits reversible dehydration and good adsorption behaviour. Magnetic susceptibility measurements indicate that the solid orders antiferromagnetically.     

New open framework in the structure of K3[Cu3FZn2(PO4)4]

K₃[Cu₃FZn₂(PO₄)₄] has been prepared by hydrothermal synthesis and the crystal structure was determined by single crystal X-ray analysis: space group C2/c, a = 37.824(8), b = 9.813(2), c = 16.679(3) Å, β = 92.70(3)°, wR₂ = 0.057, R = 0.0255. An open framework structure is built by [CuO₅] and [CuO₄F] square pyramids, [CuO₄] flattened tetrahedra, [ZnO₄] and [PO₄] tetrahedra with potassium ions in the channels.     

Phase Equilibria in the System CuO‐NiO‐P4O10 and Synthesis,Crystal Structure,and Characterization of the New Copper Nickel Oxide Phosphate Cu3NiO(PO4)2

The system CuO‐NiO‐P₄O₁₀ was investigated using a solid state reaction between CuO, NiO, and (NH₄)₂HPO₄ in quartz crucibles at 900 °C. The powder samples were characterized by X‐ray diffraction, TG/DTA, electrochemical measurements, IR, and UV/Vis spectroscopy. Single crystals of a new quaternary phase Cu₃NiO(PO₄)₂ were achieved by cooling the melted compound in a sealed, evacuated quartz ampoule. Cu₃NiO(PO₄)₂ crystallizes in the monoclinic space group P2₁/n (no 14) with a = 8.2288(2) Å, b = 9.8773(2) Å, c = 8.2777(3) Å, β = 107.82(2)°, Z = 4. The three‐dimensional framework consists of distorted tetragonal pyramides [Cu1O₅], distorted planar squares [Cu2O₄], octahedra [Cu3O₆], and [NiO₆] and [PO₄] tetrahedra. The TG‐DTA of the new phase showed an incongruent melting at 1055 °C. The open circuit voltage of this material was measured to determine the electrochemical properties. The measurement revealed an initial capacity of 236 Ah · g^–1 and a voltage plateau at 2.05 V. Furthermore, it was possible to identify the phase equilibria and to obtain the phase diagram at 900 °C.     

Polymorphism of [Zn(2,2′‐bipy)(H2PO4)2]2

Two polymorphs of a zero‐dimensional (molecular) zinc phosphate with the formula [Zn(2,2′‐bipy)(H₂PO₄)₂]₂ have been synthesized by a mild hydrothermal route and their crystal structures were determined by single crystal X‐ray diffraction (triclinic, space group (No. 2), Z = 2, α‐form: a = 8.664(1), b = 8.849(2), c = 10.113(2) Å, α = 97.37(2)°, β = 100.54(2)°, γ = 100.98(2)°, V = 737.5(3) ų; β‐form: a = 7.5446(15), b = 10.450(2), c = 10.750(2) Å, α = 67.32(3)°, β = 81.67(3)°, γ = 69.29(3)°, V = 731.4(3) ų). Both structures consist of distorted trigonal‐bipyramidal ZnO₃N₂ units condensed with PO₂(OH)₂ tetrahedra through common vertices giving rise to dimers [Zn(2,2′‐bipy)(H₂PO₄)₂]₂. The structures are stabilized by extensive inter‐ and intramolecular hydrogen bond interactions. Both modifications display subtle differences in their packing originating from the hydrogen bond interactions as well as π…π interactions between the organic ligands.     

NaSc3[HPO3]2[HPO2(OH)]6: Synthesis,Crystal Structure,and Thermal Decomposition

NaSc₃[HPO₃]₂[HPO₂(OH)]₆ was prepared by use of a phosphorus acid flux route. The crystal structure was determined from single‐crystal X‐ray diffraction data: triclinic, space group P$\bar{1}$ (No. 2), a = 7.4507(11) Å, b = 9.6253(17) Å, c = 9.6141(16) Å, α = 115.798(4)°, β = 101.395(4)°, γ = 101.136(3)°, V = 577.29(16) Å³ and Z = 1. The crystal structure of NaSc₃[HPO₃]₂[HPO₂(OH)]₆ contains two kinds of phosphate(III) groups: HPO₃^2– and HPO₂(OH)^–. Phosphate(III)‐tetrahedra, NaO₆ and ScO₆ octahedra together form a (3,6)‐connected net. During heating hydrogen and water are released and Sc[PO₃]₃ is formed as the main crystalline decomposition product.     

Beiträge zur Kristallchemie und zum thermischen Verhalten von wasserfreien Phosphaten. XXXXII Die ersten Iridiumphosphate

The First Iridiumphosphates Two polymorphs of iridium(III)‐metaphosphate Ir(PO₃)₃ and an iridium(IV)‐silicophosphate (Ir_1?xSi_x)₃[Si₂O(PO₄)₆] (x ～ 0.5) were synthesized and their crystal structures determined from single‐crystal x‐ray data. Pale pink needles of triclinic Ir(PO₃)₃ (Ru(PO₃)₃ structure type, (No. 2), Z = 2, a = 6.9574(6) Å, b = 10.3628(9) Å, c = 5.0288(4) Å, α = 92.28(1)°, β = 92.80(1)°, γ = 98.60(1)°, 1574 independent reflections, 122 parameters, R₁ = 0.028, wR₂ = 0.061) were grown from a metaphosphoric acid melt. Pale pink prisms of C‐type Ir(PO₃)₃ (C‐Al(PO₃)₃ structure type, Cc (No. 14), Z = 12, a = 13.103(2) Å, b = 19.183(1) Å, c = 9.354(1) Å, β = 127.19(1)°, 4254 independent reflections, 354 parameter, R₁ = 0.024, wR₂ = 0.062) were obtained by chemical vapour transport (900 °C → 800 °C, addition of IrCl₃·xH₂O). Both metaphosphates are built of [Ir^IIIO₆] octahedra and infinite chains. The latter have a translation period of three phosphate tetrahedra in the triclinic modification and six in the monoclinic. 1D and double‐quantum filtered 2D ³¹P‐MAS‐NMR spectra of C‐type Ir(PO₃)₃ confirm the chain structure and reveal a chemical shift range between ?4,8 and ?30,9 ppm for the 9 crystallographically independent, however chemically similar phosphate groups. Pale orange crystals of (Ir_1?xSi_x)₃[Si₂O(PO₄)₆] (Si₃[Si₂O(PO₄)₆] structure type, (No. 148), Z = 3, a = 7.8819(8) Å, c = 24.476(4) Å, 1086 independent reflections, 56 parameters, R₁ = 0.061, wR₂ = 0.190) occurred in chemical vapour transport experiments aiming at the crystallization of C‐Ir(PO₃)₃. The crystal structure of the silicophosphate consists of isolated [Ir^IVO₆] octahedra and [Si₂O(PO₄)₆]^12? heteropolyanions.     

Structure Cristalline du Trimétaphosphate d'Indium(III)

Crystal Structure of In (PO₃)₃ Indium(III) trimetaphosphate In(PO₃)₃ crystallizes in the monoclinic space group Ic with a = 10.876(2) Å, b = 19.581(2) Å, c = 9.658(2) Å, β = 97.77(1)° and Z = 12. The structure was refined to R = 0.027 utilizing 1171 independent reflections. The structure consists of infinite chains of [PO₄] tetrahedra sharing corners with each other. InO₆ octahedra connect parallel chains. Each oxygen atom is shared between two [PO₄] tetrahedra (in the infinite chains (PO₃)_n) or one [PO₄] tetrahedron and one [InO₆] octahedron. For the first type of oxygen atoms (O_M) the P? O distances are about 0.1 Å greater than the P? O distances of the second type of oxygen atoms (O_m). The [InO₆] groups are moderately distorted and the average In? O bond length for the three In³⁺ ions is 2.117 Å.     

K3[Fe3.26V0.74(OH)O(PO4)4(H2O)2]·2H2O: a synthetic leucophosphite

A new iron(III)/vanadium(III) phosphate, K₃[Fe_3.26V_0.74(OH)O(PO₄)₄(H₂O)₂]·2H₂O (1), has been obtained by hydrothermal synthesis and characterized by single crystal X-ray diffraction, Scanning electron microscopy–energy dispersive X-ray spectroscopy, Inductively coupled plasma atomic emission spectroscopy (ICP), thermogravimetric analysis, and FTIR spectroscopy. Single crystal X-ray diffraction reveals a 3D open framework (monoclinic, space group P2₁/n, a?=?9.6391(7)?Å, b?=?9.8063(7)?Å, c?=?9.7268(7)?Å, β?=?100.71(1)°, and V?=?903.38(11)?ų). This structure presents Fe^III and V^III in a 4.4?:?1?M ratio with the metal ions in two different crystallographic sites. Both metallic centers have distorted octahedral environments, linked by PO₄ tetrahedra, forming channels along the a-axis. The asymmetric unit of K₃[Fe_3.26V_0.74(OH)O(PO₄)₄(H₂O)₂]·2H₂O presents a {M₄(OH)O(PO₄)₄(H₂O)₂}^3? anionic entity, charge balanced by three K⁺, which are located within the channels. It is also possible to distinguish M₄O₂ units whose M^III polyhedra are linked by vertex and edges.