High-pressure synthesis and structural characterization of three new polyphosphides, α-SrP3, BaP8, and LaP5

Three novel metal polyphosphides, α-SrP₃, BaP₈, and LaP₅, were prepared in BN crucibles by the reaction of the respective stoichiometric mixtures under a high pressure of 3 GPa at 950-1000°C. Their crystal structures were determined from single-crystal X-ray data (α-SrP₃: space group C2/m, a=9.199(6) Å, b=7.288(3) Å, c=5.690(3) Å, β=113.45(4)°, Z=4, R₁/wR₂=0.0684/0.1180 for 471 observed reflections and 22 variables; BaP₈: space group P−1, a=6.762(2) Å, b=7.233(2) Å, c=8.567(2) Å, α=86.32(2)°, β=84.31(2)°, γ=70.40(2)°, Z=2, R₁/wR₂=0.0476/0.1255 for 2702 observed reflections and 82 variables; LaP₅: space group P2₁/m, a=4.885(1) Å, b=9.673(3) Å, c=5.577(2) Å, β=105.32(2)°, Z=2, R₁/wR₂=0.0391/0.1034 for 1272 observed reflections and 31 variables). α-SrP₃ is isostructural with SrAs₃ and the crystal structure consists of two-dimensional puckered polyanionic layers _∞²[P₃]²⁻ that stack along the c-axis yielding channels occupied by Sr²⁺ counterions. BaP₈ crystallizes in a new structure type which contains a three-dimensional infinite polyanionic framework _∞³[P₃]²⁻, with large channels hosting the barium cations. LaP₅ is a layered compound containing _∞²[P₅]³⁻ polyanionic layers separated by La³⁺ ions. All three compounds exhibit expected diamagnetic behaviors.     

Hydrothermal synthesis of two layered indium oxalates with 12-membered apertures

Two layered indium oxalates, In(C₂O₄)_2.5(C₃N₂H₁₂)(H₂O)₃, I, and In(C₂O₄)_1.5(H₂O)₃, II, have been hydrothermally synthesized. In I, the linkage between indium and oxalate units gives rise to a sheet with a rectangular 12-membered aperture (six indium atoms and six oxalate units). Indium atom of II has an unusual pentagonal bipyramidal coordination arrangement. The connectivity between indium and oxalate units forms a neutral puckered layer with 12- (along a-axis) and eight-membered (along b-axis) apertures. Crystal data for these two indium oxalates are as follows: I, triclinic, space group: P-1 (No. 2), a=8.725(3) Å, b=9.170(3) Å, c=9.901(3) Å, α=98.101(4)°, β=97.068(4)°, γ=102.403(4)°, V=756.3(4) Å³, Z=2, M=463.0(5), ρ_calc=2.042 g/cm³, R₁=0.0377, wR₂=0.0834. II, monoclinic, space group: P2₁/c (No. 14), a=10.203(5) Å, b=6.638(1) Å, c=11.152(7) Å, β=95.649(4)°, V=751.7(4)ų, Z=4, M=300.9(0), ρ_calc=2.659 g/cm³, R₁=0.0229, wR₂=0.0488. TG analyses indicate the water molecules of I can be removed at 150°C. The dehydrated product retains structural integrity.     

A novel three-dimensional inorganic framework: hydrothermal synthesis and crystal structure of CuMo3O10·H2O

A novel three-dimensional inorganic bimetallic compound Cu[Mo₃O₁₀]·H₂O 1 has been hydrothermally synthesized and structurally characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the orthorhombic system, space group Pnma, a=8.6085(17) Å, b=7.5822(15) Å, c=13.690(3) Å, V=893.6(3) Å³, Z=4, λ(MoKα) = 0.71073 Å (R(F)=0.0357 for 1101 reflections). The structure of compound 1 is based on [{Mo₃O₁₀}²⁻]_∞ isopolyoxomolybdate chains bonded together with CuO₄ tetrahedra into a three-dimensional inorganic open framework. Three types of Mo-Cu layers and one-dimensional tunnels are observed in the title compound.     

Topologically novel copper molybdate phases based on 3,4′-dipyridylketone: Hydrothermal synthesis, structural characterization, and magnetic properties

Hydrothermal treatment of CuCl₂·2H₂O, MoO₃, and 3,4′-dipyridylketone (3,4′-dpk) in 1:1:2 mole ratio afforded the new mixed metal oxide phases [Cu₂(MoO₄)₂(3,4′-dpk)(H₂O)] (1) or [Cu₄(3,4′-dpk)₄(Mo₈O₂₆)] (2), depending on the pH of the initial reaction mixture. Compound 1 possesses unique one-dimensional (1-D) [Cu₂(MoO₄)₂(H₂O)]_n ribbons constructed from the linkage of {Cu^II₄O₆} tetrameric units through isolated [MoO₄]^2- tetrahedra. These ribbons in turn are connected into a two-dimensional (2-D) coordination polymer structure by tethering 3,4′-dpk ligands. Compound 2, containing monovalent copper ions, manifests an unprecedented “X-rail” 1-D extended structure with (6²8)₄(6⁶) topology formed from the bracketing of discrete [β-Mo₈O₂₆]^4- anions by four chains. The variable temperature magnetic susceptibility behavior of 1 was fit to a linear tetramer model, with g=2.03(3), J₁=25.8(7) cm^-1 and J₂=−46(1) cm^-1. Antiferromagnetic inter-tetramer interactions (zJ′=−0.21(3) cm^-1) were also evident. Crystallographic data: 1 monoclinic, P2₁/c, a=10.3911(11) Å, b=6.9502(6) Å, c=22.958(2) Å, β=100.658(7)°, V=1629.5(3) Å³, R₁=0.1256, and wR₂=0.2038; 2 triclinic, a=10.9000(3) Å, b=11.7912(4) Å, c=13.5584(4) Å, α=102.482(2)°, β=102.482(2)°, γ=117.481(2)°, V=1450.98(8) Å³, R₁=0.0428, and wR₂=0.0630.     

The first indium-organic two-dimensional layer network with rhombus grids

The indium(III)-organic compound [In(HBtc)₂(4,4′-bpy)](4,4′-Hbpy)(H₂O)_0.5 (Btc=1,3,5-benzenetricarboxylate, 4,4′-bpy=4,4′-bipyridine) has been synthesized under hydrothermal condition and characterized by IR, fluorescent spectroscopy, TGA and single-crystal X-ray diffraction analyses. The compound crystallizes in monoclinic, space group P2(1)/c, a=17.0884(2) Å, b=12.28390(10) Å, c=17.9456(4) Å, β=104.1920(10)°, V=3652.03(10) Å³, Z=4, R₁=0.0572 and wR₂=0.1116 [I>2σ(I)]. All the indium atoms in the compound are hepta-coordinated and link 1,3,5-benzenetricarboxylate forming a 2-D layer structure with rhombus grids.     

Synthesis and structural investigation of the compounds containing HF2 anions: Ca(HF2)2, Ba4F4(HF2)(PF6)3 and Pb2F2(HF2)(PF6)

Three new compounds Ca(HF₂)₂, Ba₄F₄(HF₂)(PF₆)₃ and Pb₂F₂(HF₂)(PF₆) were obtained in the system metal(II) fluoride and anhydrous HF (aHF) acidified with excessive PF₅. The obtained polymeric solids are slightly soluble in aHF and they crystallize out of their aHF solutions. Ca(HF₂)₂ was prepared by simply dissolving CaF₂ in a neutral aHF. It represents the second known compound with homoleptic HF environment of the central atom besides Ba(H₃F₄)₂. The compounds Ba₄F₄(HF₂)(PF₆)₃ and Pb₂F₂(HF₂)(PF₆) represent two additional examples of the formation of a polymeric zigzag ladder or ribbon composed of metal cation and fluoride anion (MF⁺)_n besides PbF(AsF₆), the first isolated compound with such zigzag ladder. The obtained new compounds were characterized by X-ray single crystal diffraction method and partly by Raman spectroscopy. Ba₄F₄(HF₂)(PF₆)₃ crystallizes in a triclinic space group P1¯ with a=4.5870(2) Å, b=8.8327(3) Å, c=11.2489(3) Å, α=67.758(9)°, β=84.722(12), γ=78.283(12)°, V=413.00(3) Å³ at 200 K, Z=1 and R=0.0588. Pb₂F₂(HF₂)(PF₆) at 200 K: space group P1¯, a=4.5722(19) Å, b=4.763(2) Å, c=8.818(4) Å, α=86.967(10)°, β=76.774(10)°, γ=83.230(12)°, V=185.55(14) ų, Z=1 and R=0.0937. Pb₂F₂(HF₂)(PF₆) at 293 K: space group P1¯, a=4.586(2) Å, b=4.781(3) Å, c=8.831(5) Å, α=87.106(13)°, β=76.830(13)°, γ=83.531(11)°, V=187.27(18) Å³, Z=1 and R=0.072. Ca(HF₂)₂ crystallizes in an orthorhombic Fddd space group with a=5.5709(6) Å, b=10.1111(9) Å, c=10.5945(10) Å, V=596.77(10) Å³ at 200 K, Z=8 and R=0.028.     

Hydrothermal synthesis, structure, and magnetic properties of Pu(SeO3)2

The reaction between PuO₂ and SeO₂ under mild hydrothermal conditions results in the formation of Pu(SeO₃)₂ as brick-red prisms. This compound adopts the Ce(SeO₃)₂ structure type, and consists of one-dimensional chains of edge-sharing [PuO₈] distorted bicapped trigonal prisms linked by [SeO₃] units into a three-dimensional network. Crystallographic data: Pu(SeO₃)₂, monoclinic, space group P2₁/n, a=6.960(1) Å, b=10.547(2) Å, c=7.245(1) Å, β=106.880(9)°, V=508.98(17) Å³, Z=4 (T=193 K), R(F)=2.92% for 83 parameters with 1140 reflections with I>2σ(I). Magnetic susceptibility data for Pu(SeO₃)₂ are linear from 35 to 320 K and yield an effective moment of 2.71(5) μ_B and a Weiss constant of −500(5) K.     

Cation-controled formation of N,N′-dialkylimidazolium cadmium-thiocyanate complexes: synthesis and structural characterization

Three new N,N′-dialkylimidazolium salts of cadmium-thiocyanate, [EtMeIm]₂[Cd₂(SCN)₆] (2), [C₆H₄(CH₂ImMe)₂][Cd(SCN)₄] (3), [C₆Me₃(CH₂ImMe)₃][CdBr₃(SCN)](NO₃) (4) have been prepared, and their crystal structures have been determined by X-ray diffraction. Crystal data: 2, monoclinic, C2/c, a=18.349(4) Å, b=7.8667(18) Å, c=21.399(5) Å, β=110.346(4)°, V=2896.1(11) Å³, Z=4, and R1=0.0561; 3, monoclinic, C2/c, a=20.347(7) Å, b=14.029(5) Å, c=9.380(3) Å, β=112.034(6)°, V=2482.1(15) Å³, Z=4, and R1=0.0397; 4, hexagonal, P6₃, a=b=10.7634(8) Å, c=16.0315(17) Å, V=1608.4(2) Å³, Z=2, and R1=0.0569. Compound 2 consists of triply bridged infinite one-dimensional cadmium-thiocyanate chains, and two independent cadmium atoms are octahedrally coordinated in 2N4S and 4N2S geometry, respectively. In 3, the cadmium atom is octahedrally coordinated with two cis N-bonded monodentate NCS⁻ ligands and four bridging SCN⁻ in a S trans to S, and N trans to N coordination fashion, and thus form doubly bridged infinite one-dimensional chains. Whereas 4 is mononuclear, consisting of a discrete [C₆Me₃(CH₂ImMe)₃]³⁺ cation, a nitrate, and [CdBr₃(SCN)]⁻ ion, and each cadmium(II) ion is coordinated to three bromide and one nitrogen atom of SCN⁻ ion. The structures of these compounds are dictated by the imidazolium cations.     

Synthesis, structure and physicochemical characterization of a noncentrosymmetric, quaternary thiostannate: EuCu2SnS4

EuCu₂SnS₄ was prepared by a stoichiometric combination of the elements heated to 700 °C for 125 h. The structure was determined by single crystal X-ray diffraction methods. The compound crystallizes in the noncentrosymmetric, orthorhombic space group Ama2 with a=10.4793(1) Å, b=10.3610(2) Å, c=6.4015(1) Å, Z=4, R1=0.99% and wR2=2.37%. The structure type is that of SrCu₂GeSe₄. The structure can be described as a three-dimensional network built from near perfect SnS₄ and distorted CuS₄ tetrahedra together with EuS₈ square antiprisms. The dark red compound is a semiconductor with an optical bandgap of 1.85 eV.     

Sr4AlNbO8: A new crystal structure type determined from powder X-ray data

Sr₄AlNbO₈ was synthesized at 1500 °C in air. The crystal structure was initially determined from powder X-ray diffraction data, and later refined with combined X-ray and neutron diffraction data (P2₁/c; a=7.17592(2) Å, b=5.80261(2) Å, c=19.7408(1) Å; β=97.5470(1)°, V=814.869(3) Å³, Z=4, R_p/R_wp=10.04%/13.18% for X-ray data, 4.40%/5.67% for neutron data, and 7.71%/10.74% in total with χ² of 3.76, 23 °C). The crystal structure is a new structure type and may be described as a three-dimensional polyhedral network resulting from the corner-sharing of NbO₆ and Sr1O₆ octahedra and AlO₄ tetrahedra. Also, the other strontium atoms (Sr2, Sr3, and Sr4) occupy the larger cavities surrounded by oxygen atoms to form nine, eight, and 11 coordination, respectively. Considering that Sr, Al, and Nb atoms are crystallographically distinct in terms of interatomic distances and polyhedral coordination, Sr₄AlNbO₈ can be regarded as a stoichiometric compound.     

Hydrothermal synthesis and characteristics of 3-D hydrated bismuth oxalate coordination polymers with open-channel structure

Two new 3-D porous bismuth coordination polymers, (C₅NH₆)₂[Bi₂(H₂O)₂(C₂O₄)₄]·2H₂O 1 and (NH₄)[Bi(C₂O₄)₂]·3H₂O 2, have been hydrothermally synthesized and characterized by single-crystal X-ray diffraction. Compound 1 crystallizes in the monoclinic symmetry, P2₁/c space group with a=10.378(2) Å, b=17.285(3) Å, c=16.563(5) Å, α=90°, β=119.66(2)°, γ=90°, V=2581.8(10) Å³, Z=4, R₁=0.0355 and wR₂=0.0658 for unique 4713 reflections I >2σ(I). Compound 2 crystallizes in the tetragonal symmetry, I4₁/amd space group with a=11.7026(17) Å, b=11.7026(17) Å, c=9.2233(18) Å, α=90°, β=90°, γ=90°, V=1263.1(4) Å³, Z=32, R₁=0.0208 and wR₂=0.0518 for unique 359 reflections I> 2σ(I). Compounds 1 and 2 are 3-D open-framework structures with a 6⁶ uniform net, which consist of honeycomb-like layers connected to each other by oxalate units. While different guest molecules fill in their cavities of honeycomb-like layers, study of ultrasonic treatment on 2 indicates the replacement of NH₄⁺ by K⁺ on potassium ion exchange. Thermogravimetric analysis indicates that the open-channel frameworks are thermally stable up to 200 °C, and other characterizations are also described by elemental analysis, IR and ultraviolet-visible diffuse reflectionintegral spectrum (UV-Vis DRIS).     

Hydrothermal synthesis, crystal structure and properties of 2-D and 3-D lanthanide sulfates

Two new lanthanum sulfates DySO₄(OH) 1 and Eu₂(SO₄)₃(H₂O)₈2 have been hydrothermally synthesized. The colorless crystals were characterized by IR, TGA, ICP and XRD. The structure was determined by single-crystal X-ray diffraction. 1 crystallizes with monoclinic symmetry, space group P2(1)/n [a=7.995(4) Å, b=10.945(5) Å, c=8.164(4) Å, α=90°, β=93.619(6)°, γ=90°, V=713.0(5) Å³, Z=8]. It displays a three-dimensional framework, based on the novel Dy-O chains connected by the sulfate groups through helical chains. 2 crystallizes with monoclinic symmetry, space group C2/c, [a=13.5605(17) Å, b=6.7676(8) Å, c=18.318(2) Å, α=90°, β=102.265(2)°, γ=90°, V=1642.7 (4) Å³, Z=4]. Its layered framework is attained by the europium atoms connected by the sulfate groups arranged in a helical manner.     

Synthesis and crystal structure of two new uranyl oxychloro-vanadate layered compounds: M7(UO2)8(VO4)2O8Cl with M=Rb, Cs

Two new alkali uranyl oxychloro vanadates M₇(UO₂)₈(VO₄)₂O₈Cl with M=Rb, Cs, have been synthesized by solid-state reactions and their structures determined from single-crystal X-ray diffraction data. They crystallize in the orthorhombic system with space groups Pmcn and Pmmn, respectively. The a and b unit cell parameters are almost identical in both compounds while the c parameter in the Rb compound is doubled: Rb—a=21.427(5) Å, b=11.814(3) Å, c=14.203(3) Å, V=3595.1(1) Å³, Z=4, ρ_mes=5.93(2) g/cm³, ρ_cal=5.82(1) g/cm³; Cs—a=21.458(3) Å, b=11.773(2) Å, c=7.495(1) Å, V=1893.6(5) Å³, Z=2, ρ_mes=6.09(2) g/cm³, ρ_cal=6.11(1) g/cm³. A full-matrix least-squares refinement yielded R₁=0.0221, wR₂=0.0562 for 2675 independent reflections and R₁=0.0386, wR₂=0.1042 for 2446 independent reflections, for the Rb and Cs compounds, respectively. Data were collected with Mo(Kα) radiation and a charge coupled device (CCD) detector of a Bruker diffractometer. Both structures are characterized by [(UO₂)₈(VO₄)₂O₈Cl]_n⁷ⁿ⁻ layers parallel to the (001) plane. The layers are built up from VO₄ tetrahedra, UO₇ and UO₆Cl pentagonal bipyramids, and UO₆ distorded octahedra. The UO₇ and UO₆Cl pentagonal bipyramids are associated by sharing opposite equatorial edges to form infinite chains (UO₅-UO₄Cl-UO₅)_n parallel to the a axis. These chains are linked together by VO₄ tetrahedra, UO₆ octahedra, UO₇ corner sharing and UO₆Cl, Cl sharing. Both structures differ simply by the symmetry of the layers. The unit cell contains one centrosymmetric layer in the Cs compound, whereas in the two-layer unit cell of the Rb compound, two non-centrosymmetric consecutive layers are related by an inversion center. The layers appear to be held together by the alkali ions. The mobility of the M⁺ ions within the interlayer space in M₇(UO₂)₈(VO₄)₂O₈Cl and carnotite analog compounds is compared.     

Crystal chemistry and crystallography of the SrR2CuO5 (R=lanthanides) phases

The crystal chemistry and crystallography of the compounds SrR₂CuO₅ (Sr-121, R=lanthanides) were investigated using the powder X-ray Rietveld refinement technique. Among the 11 compositions studied, only R=Dy and Ho formed the stable SrR₂CuO₅ phase. SrR₂CuO₅ was found to be isostructural with the “green phase”, BaR₂CuO₅. The basic structure is orthorhombic with space group Pnma. The lattice parameters for SrDyCuO₅ are a=12.08080(6) Å, b=5.60421(2) Å, c=7.12971(3) Å, V=482.705(4) Å³, and Z=8; and for the Ho analog are a=12.03727(12) Å, b=5.58947(7) Å, c=7.10169(7) Å, V=477.816(9) Å³, and Z=8. In the SrR₂CuO₅ structure, each R is surrounded by seven oxygen atoms, forming a monocapped trigonal prism (RO₇). The isolated CuO₅ group forms a distorted square pyramid. Consecutive layers of prisms are stacked in the b-direction. Bond valence calculations imply that residual strain is largely responsible for the narrow stability of the SrR₂CuO₅ phases with R=Dy and Ho only. X-ray powder reference diffraction patterns for SrDy₂CuO₅ and SrHo₂CuO₅ were determined.     

The role of cation-cation interactions in a neptunyl chloride hydrate and topological aspects of neptunyl structural units

The compound K₄(NpO₂)₃Cl₇(H₂O)₄ was synthesized by evaporation of a Np⁵⁺-bearing solution. The crystal structure was determined by single crystal X-ray diffraction and refined to R₁=0.0374. The compound is triclinic, P−1, a=8.882(1) Å, b=12.082(2) Å, c=12.403(2) Å, α=65.855(2)°, β=69.604(2)°, γ=74.432(2)°, V=1126.0(3) Å³, and Z=2. The structure contains dimers of edge sharing Np⁵⁺ pentagonal bipyramids that are linked into infinite chains through cation-cation interactions with an additional Np⁵⁺ pentagonal bipyramid. The structural units are linked through bonds to interstitial K cations and by H bonding. A graphical representation for neptunyl structural units including cation-cation interactions is introduced.     

Crystallographic investigation of the Co-B-O system

The crystalline phases within the Co-B-O system have been investigated with a combination of powder and single crystal X-ray diffraction. By varying the synthetic conditions, four pure phases can be made by solid-state reaction: Co₃(BO₃)O₂, a homometallic ludwigite; Co₃(BO₃)₂, an orthoborate with the kotoite structure; Co₂(B₂O₅), a pyroborate; and the tetraborate Co(B₄O₇). Herein, we report the first structural refinement of the latter phase (orthorhombic, space group Pbca, a=8.1189(7) Å, b=8.621(1) Å, c=13.737(1) Å, V=961.5(2) Å³, Z=8, R₁=0.0319, wR₂=0.0693 [I>2σ(I)]). The pyroborate structure was also refined by single crystal methods in order to match the calculated powder diffraction pattern with the observed pattern (triclinic, space group , a=3.1689(3) Å, b=6.1530(5) Å, c=9.2734(7) Å, α=104.253(4)°, β=90.821(4)°, γ=92.098(5)°, V=175.08(3) Å³, Z=2, R₁=0.0159, wR₂=0.0366 [I>2σ(I)]). Flux growth of Co(B₄O₇) also yielded single crystals of the new compound Co₄(BO₂)₆O (cubic, space group , a=7.4825(3) Å, V=418.93(3) Å³, Z=2, R₁=0.0176, wR₂=0.0373 [I>2σ(I)]).     

Stereoselective synthesis of (E)-N,N-diethyl-3-(imidazo[1,2-a]pyrid-2-yl)-2-(phenylsulfonyl)propenamide

The title compound, gem-amidovinylsulfone 3, was synthesized stereoselectively by aldolic condensation of N,N-diethylphenylsulfonylacetamide 1 on imidazo[1,2-a]pyridine-2-carbaldehyde 2 adding Et₃N at the end. The X-ray crystal structure of 3 [C₂₀H₂₁N₃O₃S: M_r=383.5, monoclinic, P2₁, a=8.191(4) Å, b=21.132(2) Å, c=11.752(1) Å, β=96.40(2)°, V=2022(1) Å³, Z=4 (two molecules per asymmetric unit), D_calc=1.260 g cm⁻³, λ(Mo Kα)=0.71073 Å, μ=0.184 mm⁻¹, F(000)=808, T=293(2)K, R=0.059 for 5105 observed reflections with I≥2σ(I)] was determined, and confirmed the (E) configuration.     

Hydrothermal synthesis and characterization of a new iron phosphate structure of ladder-like chains and coordination directly by an organo-nitrogen ligand: [Fe(phen)(HPO4)(H2PO4)·0.5H2O] (phen=1,10-phenanthroline)

A coordination iron phosphate, Fe(phen)(HPO₄)(H₂PO₄)·0.5H₂O (I), has been hydrothermally synthesized and characterized by elemental analysis, IR spectral analysis, thermogravimetric analysis, and single-crystal X-ray diffraction. The title compound crystallizes in the monoclinic system, space group C2/m (No. 12), with cell parameters M=438.03, a=21.421(5) Å, b=6.4292(1) Å, c=12.190(3) Å, β=105.964(9)°, V=1614.1(6) Å³, Z=4, R₁[I>2σ(I)]=0.0545, wR₂[I>2σ(I)]=0.1186. This compound displays a new structure of ladder-like chains, in which each one-dimensional chain is constituted by the distorted octahedral units of Fe³⁺ bridged through PO₄ tetrahedron. The phen ligands in the compound bind in a bidentate fashion to the metal atoms and the ladder-like structure of the compound extends into a three-dimensional supramolecular array via π-π stacking interactions of phen ligands. Mössbauer spectroscopy shows the presence of Fe³⁺ in the octahedral coordination. Magnetic susceptibility measurement studies show that this material may model as anti-ferromagnetic.     

Synthesis and crystal structure of a new layered aluminophosphate [Al3P4O16][C6N3H17][H3O]

A new layered aluminophosphate denoted AlPO-AEPP has been synthesized under hydrothermal conditions using N-(2-aminoethyl)-piperazine (AEPP) as structure directing molecule. The compound, with the empirical formula crystallizes in the orthorhombic space group P2₁2₁2₁ (No. 19) with a=14.550(8) Å, b=16.163(8) Å, c=18.677(9) Å, Z=4, R₁=0.0253 and wR₂=0.0644. Inorganic sheets contain a 4×6 network previously found in a layered compound synthesized with 1,2-dimethylimidazole molecules. Layers stack in the ABAB sequence and are held together by doubly protonated organic molecules and H₃O⁺ cations. AlPO-AEPP represents the second example of layered aluminophosphate for which protonated water acts as a co-template along with organic molecules.     

Synthesis, structure of [H3dien]·(MF6)·H2O (M=Cr, Fe) and Fe Mössbauer study of [H3dien]·(FeF6)·H2O

Single crystals of [H₃dien]·(FeF₆)·H₂O (I) and [H₃dien]·(CrF₆)·H₂O (II) are obtained by solvothermal synthesis under microwave heating. I is orthorhombic (Pna2₁) with a=11.530(2) Å, b=6.6446(8) Å, c=13.787(3) Å, V=1056.3(2) Å³ and Z=4. II is monoclinic (P2₁/c) with a=13.706(1) Å, b=6.7606(6) Å, c=11.3181(9) Å, β=99.38(1)°, V=1034.7(1) Å³ and Z=4. The structure determinations, performed from single crystal X-ray diffraction data, lead to the R₁/wR₂ reliability factors 0.028/0.066 for I and 0.035/0.102 for II. The structures of I and II are built up from isolated FeF₆ or CrF₆ octahedra, water molecules and triprotonated amines. In both structures, each octahedron is connected by hydrogen bonds to six organic cations and two water molecules. The iron-based compound is also characterized by ⁵⁷Fe Mössbauer spectrometry: the hyperfine structure confirms the presence of Fe³⁺ in octahedral coordination and reveals the existence of paramagnetic spin fluctuations.