Didier Riou

VIII(OH){O2C–C6H4–CO2}.(HO2C–C6H4–CO2H)x(DMF)y(H2O)z(or MIL-68), a new vanadocarboxylate with a large pore hybrid topology : reticular synthesis with infinite inorganic building blocks?

V(III)(OH)[O(2)C-C(6)H(4)-CO(2)].(HO(2)C-C(6)H(4)-O(2)H)(x)(DMF)(y)(H(2)O)(z) or MIL-68 was solvothermally synthesised in a non-aqueous medium. Its structure, built up from octahedral chains connected by terephthalate linkers, exhibits large hexagonal channels containing different occluded moieties. Their irreversible removal releases a specific surface area of 603(22) m(2).g(-1)(BET).

Magnetic iron phosphates with an open framework

Abstract Despite the existence of many naturally occurring iron phosphate minerals exhibiting a rich and varied structural chemistry, the soft hydrothermal synthesis of organically templated iron phosphates has only recently become of particular interest. This results from the increasing quest for preparing new open-framework materials with potential applications in the fields of catalysis, adsorption and/or magnetic properties. This review will summarize the results concerning the synthesis, structural features and magnetic properties of all the organic–inorganic iron phosphates with a three-dimensional open framework.

[Fe4(PO4)4F2(H2O)3] · [C6H14N2] or ULM-12, the first magnetic ferric phosphate with an open structure: Hydrothermal synthesis, structure, and magnetic propertie

The first three-dimensional magnetic ferrie phosphate with an open structure [Fe4(PO4)4F2(H2O)3] · [C6H14N2] has been hydrothermally synthesized (453 K, 24 h, autogeneous pressure) from a mixture of Fe2O3, H3PO4/ HF, 1,4-diazabicyclo [2.2.2] octane (DABCO), and H2O in the ratio 1:2:2:0.5:80. The structure was determined by single crystal X-ray diffraction. It is monoclinic (space group P21/n (n∘14)) with a = 9.987(1) A, b = 12.275(1) A, c = 17.462(1) A, β = 102.78(1)∘, V= 2088(1) A3, Z= 4. The structure, refined to wR2(F2) = 0.062, R(F) = 0.026 from 5,286 reflections (1> 2σ(I)), is three-dimensional. The complex framework is built up from two types of secondary building units. In the hexamer [Fe3(PO4)3F2(H2O)2],Fe3+ octahedra form via fluorine atoms corner sharing trimers that are capped by three PO4 tetrahedra. These hexamers share four vertices along [010] and form infinite columns. These columns are linked together along [100] and [001] by dimers [FeP07(H2O)] formed by the O linkage between a Fe3+ square pyramid and a PO4 tetrahedron. The resulting framework leaves large cages limited by 3−, 4−, 6−, and 8-membered windows in which the diprotonated amines are located. Upon heating, water molecules are lost between 150 and 260°C. At 350°C, the decomposition is achieved and leads to FePO4. The title compound orders antiferromagnetically at TN = 10.7(1) K. Mossbauer spectroscopy confirms the presence of four distinct Fe3+ sites in the structure.

Synthesis, structure determination and magnetic behaviour of the first porous hybrid oxyfluorinated vanado(III)carboxylate: MIL-71 or VIII2(OH)2F2{O2C-C6H4-CO2}·H2O

A new type of three-dimensional vanadium(III) dicarboxylate, MIL-71 or VIII2(OH)2F2{O2C-C6H4-CO2}·H2O, has been obtained under hydrothermal conditions from aqueous mixtures of vanadium, 1,4-benzenedicarboxylic acid, and HF. MIL-71cal or VIV2O2F2{O2C-C6H4-CO2} is obtained by calcination of the parent compound in air at 250 °C. The three-dimensional structure of MIL-71 (S.G.: Cmmm; a = 21.4477(8) A, b = 7.1449(2) A, c = 3.8246(2) A, and Z = 2) consists of layers built from corner-sharing {VIIIO2(OH)2F2} octahedra connected by the terephthalate linkers. The role of fluorine in this structure is understood by comparison with the already known hybrid vanado(III)carboxylates. The thermal behavior of the two solids has been investigated using TGA and X-ray thermodiffractometry. Finally, magnetic measurements performed on both MIL-71 and MIL-71cal reveal a canted antiferromagnetic behavior with Neel temperatures below 20 K.

Hydrothermal synthesis, structure and magnetic properties of [Fe3(PO4)3F2, H3N(Ch2)4NH3]: The analog of the three-dimensional gallophosphate structure-type ULM-3

Abstract [Fe 3 (PO 4 ) 3 F 2 , H 3 N(CH 2 ) 4 NH 3 ] has been synthesized hydrothermally (453 K, 24 h, autogenous pressure). Its structure was determined by single-crystal X-ray diffraction. It is orthorhombic (space group Pbca No. 61) with cell parameters a = 10.203(1) A , b = 18.670(1) A , c = 16.268(1) A , V = 3099(1) A 3 and Z = 8 . Its three-dimensional structure, refined to R 1 ( F 0 ) = 0.036 and wR 2 ( F 2 0 ) = 0.093 from 6821 unique reflections ( l > 2 σ (1)) is isostructural with the oxyfluorinated gallophosphate ULM-3. From a structural point of view, this leads to 10-membered channels along [100]. It is also an antiferromagnetic compound which orders at T N = 37(2) K. Mossbauer data are consistent with the presence of two distinct Fe 3− sites in the high spin state: one corresponding to Fe 3− in an octahedral site and the other to two Fe 3+ in trigonal bipyramids. Magnetic couplings are discussed in terms of superexchange and supersuperexchange interactions.

Microporous hybrid compounds: hydrothermal synthesis and characterization of two zinciomethylenediphosphonates with 3D structures, structure determination of their dehydrated forms

The ZnCl2–H2O3P-CH2-PO3H2–NaOH–H2O quaternary system was investigated under hydrothermal conditions as a function of pH (48 h; 443 K). Zn2(H2O){O3P-CH2-PO3} (labelled VSB-3(Zn)) and NaZn2(OH){O3P-CH2-PO3}·1.5H2O (labelled MIL-48) are obtained at pH 1 and 9 respectively. Their structures were solved from single crystal X-ray diffraction. Zn2(H2O){O3P-CH2-PO3}, isostructural with Co and Ni analogues previously described, is monoclinic (C 2/c (n° 15)) with lattice parameters a = 18.7573(3) A, b = 8.2803(2) A, c = 8.9225(1) A, β = 106.815(1)°, V = 1326.56(4) A3, Z = 8, R1(Fo) = 0.0269 and wR2(Fo2) = 0.0704 for 1735 unique reflections I ≥ 2σ(I). Its thermal evolution first leads to anhydrous Zn2{O3P-CH2-PO3} (labelled VSB-4(Zn)) whose structure was refined from XRD powder pattern, then to γ and β zinc diphosphates successively. NaZn2(OH){O3P-CH2-PO3}·1.5H2O is monoclinic (P21/c (n° 14)) with lattice parameters a = 8.9929(9) A, b = 5.5093(6) A, c = 18.025(2) A, β = 92.376(2)°, V = 892.3(2) A3, Z = 4, R1(Fo) = 0.0700 and wR2(Fo2) = 0.1078 for 2358 unique reflections I ≥ 2σ(I). Its three-dimensional structure provides a new zeotype with 10-membered channels where the Na+ cations and the water molecules are encapsulated. The elimination of water provides a new compound, NaZn2(OH){O3P-CH2-PO3} (labelled MIL-48calc), whose structure was refined from XRD powder pattern.

Hybrid open-frameworks: hydrothermal synthesis, structure determinations and magnetic properties of MIL-29, two copper diphosphonates (CuII(H2O))2{O3P–X–PO3} with X=C2H4, CH2–C6H4–CH2

Abstract Two copper diphosphonates were hydrothermally synthesized using ethylenediphosphonic and p -xylenediphosphonic acids, synthesized according the Arbuzov method. The structure of (Cu II (H 2 O)) 2 {O 3 P–CH 2 –CH 2 –PO 3 } already described from powder data, was solved from single crystal data. Its symmetry is monoclinic (space group P2 1 /c (no. 14)) with lattice parameters a =8.0670(4) A, b =7.5889(4) A, c =7.3997(4) A, β =116.281(2)°, V =406.18(4) A 3 , Z =2. The structure of (Cu II (H 2 O)) 2 {O 3 P–CH 2 –(C 6 H 4 )–CH 2 –PO 3 } was solved by powder X-ray diffraction (space group P2 1 /c (no. 14)) with lattice parameters a =10.812(1) A, b =7.577(1) A, c =7.412(1) A, β =92.34(1)°, V =606.7(2) A 3 , Z =2. Both structures are built up from identical inorganic layers covalently linked by the organic chains which act as pillars. The inorganic layers contain dimers of edge-sharing CuO 4 (H 2 O) square pyramids linked by the PO 3 C tetrahedra. Both compounds are antiferromagnetic at 4(1) K.

Hybrid open-frameworks: synthesis and structures of four vanado-alkyldiphosphonates with occluded potassium cations

Abstract The ternary systems KVO3:H2O3P (CH2)n PO3H2:H2O (n=1, 2, 3) were hydrothermally investigated. Four phases were obtained and their structures determined by single crystal X-ray diffraction. K4(VIVO)2(VIVO(H2O))4{O3P CH2 PO3}4.8H2O or MIL-2K is orthorhombic (S.G. P mmn (n° 59)) with lattice parameters a=13.7642(2) A, b=15.6796(4) A, c=4.6902(1) A, V=1012.23(4) A3, Z=1. Its three-dimensional framework presents some 14-membered tunnels inserting potassium cations and water molecules. K(VVO(H2O))(VIVO)O{O3P (CH2)2 PO3} or MIL-3K is triclinic (S.G. P -1 (n° 2)) with lattice parameters a=7.3807(2) A, b=7.9984(3) A, c=10.0641(3) A, α=75.695(1)°, β=69.178(1)°, γ=80.769(1)°, V=536.37(3) A3, Z=2. MIL-3K exhibits a pillared structure showing inorganic layers covalently linked by the ethyl chains. Its dehydration is studied. The pillared structures of K(VIVO)2(OH){O3P (CH2)3 PO3}3H2O or MIL-7K(HT) and K(V2IV/VO3)(H2O){O3P (CH2)3 PO3}H2O or MIL-7K(LT) are closely related, differing only by the neighbouring and the oxidation state of one vanadium atom. Both structures are monoclinic (S.G. C 2/c (n° 15)) with lattices parameters a=14.4939(1) A, b=10.2595(2) A, c=18.6782(2) A, β=98.991(1)°, V=2743.32(6) A3, Z=8 and a=14.6228(1) A, b=10.2783(2) A, c=18.2716(3) A, β=100.272(1)°, V=2702.16(7) A3, Z=8 for MIL-7K(HT) and MIL-7K(LT), respectively.

[VIII(H2O)]3O(O2CC6H4CO2)3·(Cl, 9H2O) (MIL-59): a rare example of vanadocarboxylate with a magnetically frustrated three-dimensional hybrid framework

[V(III)(H2O)]3O(O2CC6H4CO2)3.(Cl, 9H2O) (denoted MIL-59) presents a three-dimensional framework built up from octahedral vanadium trimers joined via the isophthalate anionic linkers to delimit cages where water molecules and chlorine anions are occluded; the frustrated magnetic behaviour of MIL-59 is discussed.

A Two-Dimensional Iron Phosphate Templated by Ethylenediamine

[Fe(PO 4 )(OH)].0.5(ethylenediamine) was synthesized hydrothermally at 453 K. It is isotypic with the layered gallophosphate obtained in ethylene glycol by Jones, Thomas, Qisheng, Hursthouse & Chen [J. Chem. Soc. Chem. Commun. (1991), pp. 1520-1522].