Tris[4,4′-(ethene-1,2-di­yl)dipyridinium] deca­vanadate dihydrate

The asymmetric unit of the title compound, (C12H12N2)3[V10O28]·2H2O, contains one half of a deca­vanadate anion, one and a half trans-1,2-bis­(4-pyridinio)ethene cations and one water mol­ecule. The V10O28 groups are involved in a three-dimensional hydrogen-bonding network through Ow—H⋯O, N—H⋯O and C—H⋯O inter­actions

Amine templated open-framework vanadium(III) phosphites with catalytic properties

Four novel amine templated open-framework vanadium(III) phosphites with the formula (C5N2H14)0.5[V(H2O)(HPO3)2], 1 (C5N2H14 = 2-methylpiperazinium), and (L)4−x(H3O)x[V9(H2O)6(HPO3)14−y(HPO4)y(H2PO3)3−z(H2PO4)z]·nH2O (2, L = cyclopentylammonium, x = 0, y = 3.5, z = 3, n = 0; 3, L = cyclohexylammonium, x = 1, y = 0, z = 0.6, n = 2.33; 4, L = cycloheptylammonium, x = 1, y = 0, z = 0, n = 2.33) were synthesized employing solvothermal reactions and characterized by single-crystal X-ray diffraction, ICP-AES and elemental analyses, thermogravimetric and thermodiffractometric analyses, and IR and UV/vis spectroscopy. Single-crystal data indicate that 1 crystallizes in the triclinic system, space group P, whereas 2, 3 and 4 crystallize in the hexagonal space group P63/m. Compound 1 has a two-dimensional motif with anionic sheets of [V(H2O)(HPO3)2]− formula, whose charge is compensated by the 2-methylpiperazinium cations embedded between the layers. In contrast, 2, 3 and 4 present a pillar-layer network giving rise to a three-dimensional framework containing intersecting 16-ring channels with the primary amine templates and the crystallization water molecules enclosed in them. 1, 2, 3 and 4 behave as heterogeneous catalysts for the selective oxidation of alkyl aryl sulfides, with tert-butylhydroperoxide (TBHP) as the oxidizing agent, being active, selective and recyclable for several successive cycles of reaction.This work has been financially supported by the “Ministerio de Ciencia e Innovación” (MAT2010-15375, MAT2011-29020-C02-02) and the “Gobierno Vasco” (IT-177-07), which we gratefully acknowledge

Thermal response, catalytic activity, and color change of the first hybrid vanadate containing Bpe guest molecules

Four isomorphic compounds with formula [{Co2(H2O)2(Bpe)2}(V4O12)]·4H2O·Bpe, CoBpe 1; [{CoNi-(H2O)2(Bpe)2}(V4O1 2)]·4H2O·Bpe, CoNiBpe 2; [{Co0.6Ni1.4(H2O)2(Bpe)2}(V4O12)]·4H2O·Bpe, NiCoBpe 3; and [{Ni2(H2O)2(Bpe)2}(V4O12)]·4H2O·Bpe, NiBpe 4, have been obtained by hydrothermal synthesis. The crystal structures of CoBpe 1 and NiBpe 4 were determined by single-crystal X-ray diffraction (XRD). The Rietveld refinement of CoNiBpe 2 and NiCoBpe 3 XRD patterns confirms that those are isomorphic. The compounds crystallize in the P1 space group, exhibiting a crystal structure constructed from inorganic layers pillared by Bpe ligands. The crystal structure contains intralayer and interlayer channels, in which the crystallization water molecules and Bpe guest molecules, respectively, are located. The solvent molecules establish a hydrogen bonding network with the coordinated water molecules. Thermodiffractometric and thermogravimetric studies showed that the loss of crystallization and coordinated water molecules takes place at different temperatures, giving rise to crystal structure transformations that involve important reduction of the interlayer distance, and strong reduction of crystallinity. The IR, Raman, and UV¿vis spectra of the as-synthesized and heated compounds confirm that the structural building blocks and octahedral coordination environment of the metal centers are maintained after the structural transformations. The color change and reversibility of the water molecules uptake/removal were tested showing that the initial color is not completely recovered when the compounds are heated at temperatures higher than 200 °C. The thermal evolution of the magnetic susceptibility indicates one-dimensional antiferromagnetic coupling of the metal centers at high temperatures. For NiCoBpe 3 and NiBpe 4 compounds magnetic ordering is established at low temperatures, as can be judged by the maxima observed in the magnetic susceptibilities. CoNiBpe 2 was proved as catalyst being active for cyanosilylation reactions of aldehydes.This work has been financially supported by the “Ministerio de Ciencia e Innovación” (MAT2010-15375 and MAT2011-29020-C02-02) and the “Gobierno Vasco” (IT-177-07), which we gratefully acknowledge. R. Fernández de Luis thanks to the MICINN (Madrid, Spain) (BES-2005-10322). E. S. Larrea thanks the UPV/EHU for funding.Peer Reviewe

Heterobimetallic MOFs for catalytic applications

Poster presented at the Third International Conference on Multifunctional, Hybrid and Nanomaterials that took place in Sorrento (Italy) during 3-7 March 2013.Open metal–organic frameworks (MOFs) are considered as promising materials for many potential applications, such as gas storage, molecular sensing, separation, ion exchange, catalysis, optics, magnetism and others.[1] A useful approach to the rational synthesis of such network species involves the use of molecular building blocks, usually metal-containing species called metalloligands,[2] that have suitably oriented peripheral exo donor groups and are therefore able to direct the formation of the polymeric array. The metalloligands are used in place of organic ligands to join different metal centres, thus possibly affording heterobimetallic architectures. We present the synthesis, characterization and catalytic properties of a new heterometallic coordination polymer with formula NaCu(2,4-Pdc)2, where 2,4-Pdc is 2,4-pyridindicarboxylate. The synthesis has been performed in two steps, firstly, synthesizing the metalloligand Cu(2,4-HPdc)2(H2O)2, and then, using the metalloligand to obtain the heterobimetallic MOF. Both reactions take place under hydrothermal conditions. The purple rod-like single-crystals crystallize in the triclinic system, space group P-1 and is isostructural to MnCu(2,4-Pdc)2 compound. [3] Sodium atoms are linked by carboxylate groups, forming chains. These chains are bridged by the Cu(2,4-Pdc)2 metalloligand. The metalloligand is also bonded to chains up and down its plane, giving rise to a 3D network.Ministerio de Ciencia e Innovación (MICINN) of the Spanish Government (MAT2010-15375), and the “Gobierno Vasco” (IT177-07) for funding. SGIker technicians support (MEC, GV/EJ, European Social Fund) is gratefully acknowledged. Edurne S. Larrea thanks the UPV/EHU for her post-doctoral contract

Low temperature red luminescence of a fluorinated Mn-doped zinc selenite

M2(SeO3)F2 (M = Zn (1), Mn (2)) stoichiometric phases together with the Zn2-xMnx(SeO 3)F2 compound doped at various concentrations (x = 0.002-0.2) were synthesized by employing mild hydrothermal conditions. These compounds have been characterized by scanning electron microscopy (SEM), Rietveld refinement of the X-ray powder diffraction patterns, ICP-Q-MS, thermogravimetric and thermodiffractometric analyses, and IR, UV/vis and electron paramagnetic resonance (EPR) spectroscopies. Compounds 1 and 2 crystallize in the orthorhombic Pnma space group with lattice parameters: a = 7.27903(4), b = 10.05232(6) and c = 5.26954(3) Å for the zinc species and a = 7.50848(9), b = 10.3501(12) and c = 5.47697(6) Å for the manganese phase, with Z = 4. The crystal structures of these compounds are isotypic and are built up from a 3D framework constructed by (010) sheets of [MO 3F3] octahedra linked up by [SeO3] building units. Luminescence measurements of Mn2(SeO3)F2 were performed at different temperatures between 10 and 150 K. At 10 K, the emission spectrum consists of a broad band peaked at around 660 nm related to the 4T1g → 6A1g transition in octahedrically coordinated Mn2+. Moreover, the influence of temperatures up to 295 K and the Mn concentration on the luminescent properties of the Zn2-xMnx(SeO3)F2 system were systematically studied. Magnetic measurements of 2 show antiferromagnetic coupling as the major interactions exhibiting a spin canting at low temperature. © 2013 The Royal Society of Chemistry.This work has been financially supported by the “Ministerio de Ciencia e Innovación” (MAT2010-15375 and FIS2011-27968) and the "Gobierno Vasco" (IT630-13) and the “UPV/EHU” (UFI11/15), which we gratefully acknowledge. Financed by the National Program for the Promotion of Human Resources within the National Plan of Scientific Research, Development and Innovation, “Ministerio de Ciencia y Educación” and “Fondo Social Europeo” (FSE).Peer Reviewe

K2Mn2II(H2O)(2)C2O4(HPO3)(2): a new 2D manganese(II) oxalatophosphite with double-layered honeycomb sheets stabilized by potassium ions

A novel 2D metal oxalatophosphite, K2Mn2II(H2O)(2)C2O4(HPO3)(2) (KMnCP), was hydrothermally synthesized and characterized. The hexagonal morphology and crystal growth faces of KMnCP were predicted by the Bravais-Friedel-Donnay-Harker (BFDH) theory. Single crystal X-ray diffraction analysis revealed that the compound displays a unique double layered structure constructed from Mn(H2O)(HPO3) single layers linked by oxalate ligands, where the potassium levels interrupt the 3D connectivity through the organic bridges. Moreover, in order to classify this archetype, a crystallochemical revision of metal oxa-latophosphites with anionic frameworks has been carried out. Several secondary building units (SBUs) formed from metal-phosphite substructures and different roles of the oxalate bridges have been observed, which has led us to propose a new structural classification for these kinds of materials that share common features with classic inorganic metal phosphates and coordination polymers. Finally, the thermal, spectroscopic and magnetic properties together with the electronic structure of the studied compound are discussed.Ministerio de Economia y Competitividad MAT2016-76739-R "Gobierno Vasco" (Basque University Research System Group) IT-630-13 "Gobierno Vasco" (Economic Development and Competitiveness, ACTIMAT) KK-2015/00094 "Gobierno Vasco" (ELKARTEK) CONICYT 315045

Mixed Metal-Organic Framework as a Heterogeneous Catalyst

The synthesis of a new mixed metal-organic framework (M′MOF) has been accomplished by the metalloligand approach. [NaCu(2,4-HPdc)(2,4-Pdc)] (2,4-H2Pdc = pyridine-2,4-dicarboxylic acid) has been obtained from the hydrothermal reaction of the metalloligand [Cu(2,4-HPdc)2(H2O)2] NaOH, and a transition metal salt. [NaCu(2,4-HPdc)(2,4-Pdc)] is isostructural to [CuMn(2,4-Pdc)2] and crystallizes in the triclinic space group P$\bar {1}$. The 3D structure is built up from [Cu(2,4-HPdc)2(H2O)2] metalloligands and [NaO6] octahedra in a pcu α-Po-like uninodal six-connected net. The compound is stable to 290 °C, and its crystal structure undergoes a 3 % volume expansion between room temperature and thermal decomposition. The unsaturated CuII centers at the surface act as a heterogeneous Lewis acid catalyst for the cyanosilylation of aldehydes and Knoevenagel C-C bond-forming reactions. The catalytic activity has been compared with those of other copper(II) porous metal-organic frameworks such as HKUST-1 and MOF-74.This work was financially supported by the Ministerio de Economía y Competitividad (MEC) (grant numbers MAT2013‐42092‐R, MAT2011‐29020‐C02‐02), the Gobierno Vasco (Basque University Research System Group) (IT‐630‐13), and University of the Basque Country (UPV/EHU) (UFI 11/15)

Hydrothermal synthesis, crystal structure, spectroscopic and magnetic properties of Mn4(H2O)3(SeO3)4 and Mn3(H2O)(SeO3)3

Two new manganese() selenites with the formula Mn4(H2O)3(SeO3)4 (1) and Mn3(H2O)(SeO3)3 (2) have been synthesized by using mild hydrothermal conditions under autogeneous pressure. The crystal structure of both compounds has been solved from single crystal X-ray data. The structures consist of a three-dimensional framework formed by MnO6 octahedra and (SeO3)2 selenite anions with trigonal pyramidal geometry. Compound 1 shows the existence of sheets constructed from zig-zag chains linked to MnO6 octahedra. Compound 2 exhibits zig-zag chains formed by edge-sharing dimeric octahedra which are interconnected by Mn2O10 octahedra. The IR and Raman spectra show the characteristic bands of the selenite anion. Studies of luminescence at 6.0 K and diffuse reflectance spectroscopy have been carried out for both compounds. The Dq and Racah parameters are Dq = 715, B = 705 and C = 3420 cm 1 for 1 and Dq = 710, B = 700 and C = 3425 cm 1 for 2. The ESR spectra are isotropic with a g-value of 2.00(1), which remains unchanged with variation in temperature. Magnetic measurements indicate the presence of antiferromagnetic interactions in both phases

Novel composition above the limit of Bi:Zr solid solution; synthesis and physical properties of Bi1.33Zr0.67O3+δ

This paper presents an increase to x = 0.67 of the zirconium content in the conductive Bi2−xZrxO3+δ solid solution. Complete incorporation of Zr in the βIII-Bi2O3 structure, confirmed by X-ray powder diffraction, has produced a phase with a lower volume and superior conductivity than those predicted by an earlier study..