M. I. Arriortua

Universidad del País Vasco / Euskal Herriko Unibertsitatea, Leioa, Basque Country, Spain

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Publications (354)924.62 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: 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 Pequation image. 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.
    European Journal of Inorganic Chemistry 09/2015; DOI:10.1002/ejic.201500431 · 2.97 Impact Factor
  • A. Moran-Ruiz · K. Vidal · A. Larranaga · P. R. Slater · M. I. Arriortua
    ECS Transactions 07/2015; 68(1):1701-1706. DOI:10.1149/06801.1701ecst
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    ABSTRACT: A Fe–22Cr mesh was dipped into a ceramic (LaNi0.6M0.4O3−δ; M: Co, Fe) slurry to form a metallic/ceramic material as contact coating for solid oxide fuel cells (SOFCs). This composite was directly adhered to a Crofer22APU channeled interconnect and micro-holes were performed on coating using a femtosecond laser. Then, La0.6Sr0.4FeO3 (LSF) cathode was spray deposited on top of this ablated system to analyze the formed structures in terms of the electrical performance, processing reproducibility and long-term behavior at 800 °C. The adequate reproducibility of the process was confirmed through area specific resistance (ASR) testing on four replicas for each system. After long-term treatment, the chromium diffusion within both the interconnect and mesh of the composite was quantitatively analyzed using energy dispersive X-ray spectroscopy (EDX). The laser irradiated composite showed short-range damage, which was limited to the formation of iron and chromium oxides due to the evaporation and oxidation of the mesh.
    International Journal of Hydrogen Energy 07/2015; 40(26). DOI:10.1016/j.ijhydene.2015.04.134 · 3.31 Impact Factor
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    ABSTRACT: The structural and magnetic properties of a series of ordered double perovskites with the formula Sr2Co1-xMgxTeO6 (x = 0:1;0:2 and 0.5) are investigated by means of X-ray diffraction, low temperature neutron diffraction, electron paramagnetic resonance and magnetic susceptibility. The progressive substitution of the paramagnetic Co2+ high spin ion by the diamagnetic Mg2+, of about the same size, induces changes in the room temperature crystal structure, from a distorted P21/n phase for the undoped Sr2CoTeO6 oxide to the I4/m of the end member (Sr2MgTeO6). These perovskites experiment structural transitions on heating, the temperature at which the transitions occurs being smaller as x increases. The novel approach of ode-crystallography is used for the analysis. All oxides show antiferromagnetic exchange interactions between Co2+ ions but the long range antiferromagnetic order is not achieved for the phase with x = 0.5. The low temperature neutron diffraction data have been evaluated using full symmetry analysis. Results are consistent with an unquenched orbital contribution of a high spin Co2+ ion.
    Dalton Transactions 06/2015; 44(30). DOI:10.1039/C5DT02026C · 4.20 Impact Factor
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    ABSTRACT: An uncoated and MnCo1.9Fe0.1O4 (MCF) coated Fe-22Cr meshes were dipped into LaNi0.6Fe0.4O3−δ (LNF) slurry to form a continuous protective/conductive layer for Crofer22APU interconnect. After aged these samples at 800 °C for 1000 h, energy dispersive X-ray (EDX) results concluded that: if the deposition of the protective coating was not enough to form a dense and continuous layer across the width of the mesh, then the use of MCF spinel layer is not enough to prevent chromium migration. For mesh-LNF/interconnect structure the area specific resistance (ASR) value of 0.0425(2) Ω cm2 was stable for 400 min at 800 °C, indicating initial good adherence between both materials. After aged this structure at 800 °C for 1000 h, without applying a current source, X-ray micro-diffraction (XRMD) results, performed at the rib and channel of the interconnect, revealed that the LNF material is acting as a protective layer. Moreover, X-ray photoelectron spectroscopy (XPS) analysis indicated that manganese is concentrated on the mesh/LNF contact surface.
    International Journal of Hydrogen Energy 04/2015; 40(14). DOI:10.1016/j.ijhydene.2015.02.052 · 3.31 Impact Factor
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    ABSTRACT: Synthetic metalloporphyrin complexes are often used as analogues of natural systems, and they can be used for the preparation of new Solid Coordination Frameworks (SCFs). In this work, a series of six metalloporphyrinic compounds constructed from different meso substituted metalloporphyrins (phenyl, carboxyphenyl and sulfonatophenyl) have been structurally characterized by means of single crystal X-ray diffraction, IR spectroscopy and elemental analysis. The compounds were classified considering the dimensionality of the crystal array, referred just to coordination bonds, into 0D, 1D and 2D compounds. This way, the structural features and relationships of those crystal structures were analyzed, in order to extract conclusions not only about the dimensionality of the networks but also about possible applications of the as-obtained compounds, focusing the interest on the interactions of coordination and crystallization molecules. These interactions provide the coordination bonds and the cohesion forces which produce SCFs with different dimensionalities.
    Molecules 04/2015; 20(4):6683-6699. DOI:10.3390/molecules20046683 · 2.42 Impact Factor
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    ABSTRACT: Compound 1 [Cu24(m-BDC)24(DMF)20(H2O)4]•24DMF•40H2O (m-BDC is 1,3-benzenedicarboxylate and DMF is N,N-dimethylformamide) has been synthesized and structurally characterized by X-ray diffraction. It consists of Cu24-clusters arranged in such a way that 12 dimers are connected through m-BDC ligands. The clusters exhibit an internal cavity where crystallization molecules of DMF and water are located. Additionally, there are guest DMF and water molecules in the voids generated by the 3D packing of the Cu24-clusters. The thermal stability of compound 1 has been also characterized, concluding that hydrogen bonds between solvent molecules are responsible for the robustness of the network. Compound 1 is similar to other seven compounds found in literature. This work is focused on the crystallochemical comparison of these compounds, which concludes that there are two mother structures related to the hexagonal and cubic close packing of spheres, respectively. Derivative compounds are produced by the presence of different solvent molecules (differences affecting both the nature and the number of the guest molecules).
    CrystEngComm 03/2015; 17(17). DOI:10.1039/C5CE00251F · 4.03 Impact Factor
  • Advances in Materials Physics and Chemistry 01/2015; 05(05):171-184. DOI:10.4236/ampc.2015.55018
  • Journal of Materials Chemistry A 01/2015; DOI:10.1039/C5TA04189A · 7.44 Impact Factor
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    ABSTRACT: The feasibility of using Crofer22APU mesh dip coated with LaNi0.6Co0.4O3−δ (LNC) ceramic paste as a uniform contact layer on a Crofer22APU channeled interconnect was studied. The control of LNC dip coating thickness on Fe–Cr mesh was carried out by rheological measurements of the suspension. SEM cross-section of formed composite contact material showed good adherence between ceramic and metallic components. The measured area specific resistance (ASR) value at 800 °C was 0.46 ± 0.01 mΩ cm2, indicating low contact resistance itself. The long term stability of metallic/ceramic composite was also studied. The contact resistance, when composite contact material was adhered to channeled Crofer22APU interconnect, was 5.40 ± 0.01 mΩ cm2, which is a suitable value for the performance of IT-SOFC stack. The stability of the system after treating at 800 °C for 1000 h was characterized using X-ray Micro-Diffraction (XRMD), Scanning Electron Microscope equipped with an Energy Dispersive X-ray analyzer (SEM-EDX) and X-ray Photoelectron Spectroscopy (XPS) techniques. The oxidation rate of the alloy and Fe3O4 phase formation were enhanced on the channels of the interconnect. Thus, the formation of CrO3 (g) and CrO2(OH)2 (g) species was accelerated on the composite surface under the channel. Through XRMD and XPS analysis the coexistence of two perovskite phases (initial LNC and Cr-perovskite) was observed.
    Journal of Power Sources 12/2014; 269:509–519. DOI:10.1016/j.jpowsour.2014.07.040 · 6.22 Impact Factor
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    ABSTRACT: The perovskite LaNi0.6Fe0.4O3 has been prepared by the glycine–nitrate route using different amounts of glycine/fuel ratio (G/N = 0.5, 1.0 and 1.5), in order to study the sample preparation influence on the properties in the context of their application as a cathode contact material for solid oxide fuel cells (SOFCs). The obtained materials have been characterized by X-ray diffraction, scanning electron microscopy, dilatometry and electrical conductivity measurements. All the compounds have rhombohedral symmetry and a porous microstructure with fine grain sizes. The sample obtained at the G/N of 1.0 has more suitable conductivity values for application as SOFC contact material.
    Solid State Ionics 11/2014; 269. DOI:10.1016/j.ssi.2014.11.002 · 2.56 Impact Factor
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    ABSTRACT: During the past years, a great effort has been devoted to the anchoring of catalysts into solid coordination networks in order to achieve heterogeneous catalysts. In this sense, an innovative approach consists on using the coordination-network synthons both as structural units and as catalysts. Regarding the latter, metalloporphyrins are suitable candidates for synthons. In fact, a few works report on coordination compounds based on metalloporphyrins exhibiting these features. On the other hand, highly distorted di-iron oxo dimers containing electron withdrawing groups rank amongst the most-effective catalyst models. Thus, the aim of this work was obtaining coordination networks based on iron porphyrins exhibiting those characteristics. This way, this work reports on the synthesis and characterisation of the μ-O-[FeTCPP]2•16DMF compound (H2TCPP = meso-tetra(4-carboxyphenyl)porphyrin, DMF = N,N-dimethylformamide). This compound is the first example of an μ-oxo dimer with TCPP. The inter-dimer connections give rise to a laminar structure. The structural, spectroscopic and magnetic properties of this compound are consistent with the presence of high-spin FeIII ions, exhibiting a strong antiferromagnetic coupling in the μ-oxo dimer (J = -132 cm-1). An unusual superhyperfine structure has been observed in EPR that is related to the high accessible volume of the compound. The structural features of the dimers and the accessible network are responsible for the excellent behaviour of the compound as a heterogeneous catalyst for different oxidation of alcohols. Therefore, this compound is a new of the very few examples of metalloporphyrins where structural units play as catalysts.
    Dalton Transactions 10/2014; 44(1). DOI:10.1039/C4DT02250E · 4.20 Impact Factor
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    ABSTRACT: Spinel oxides are promising materials as protective coatings on metallic interconnects to reduce the area specific resistance (ASR) at high operating temperature in solid oxide fuel cells (SOFC). In this work, the deposition of MnCo2O4 (MC) and MnCo1.9Fe0.1O4 (MCF10) materials (1 μm) on Si substrates and commercial alloys (Crofer 22 APU, SS430 and Conicro 4023 W 188) by electron beam physical vapour deposition (EB-PVD) was studied. Optimisation of deposition, the effectiveness of MC and MCF10 protective layers and the influence of the deposition method were investigated after oxidation at 800 °C for 100 h in air. Significant improvements in Cr poisoning of the cathode and in ASR were observed in cells assembled with coated versus uncoated samples. The best results were obtained with cells assembled with MC/Conicro 4023 W 188 with MC deposited by EB-PVD.
    International Journal of Hydrogen Energy 09/2014; 39(28):15735–15745. DOI:10.1016/j.ijhydene.2014.07.115 · 3.31 Impact Factor
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    ABSTRACT: The hybrid vanadates exhibit structural archetypes between the hybrid zeotypes in which the inorganic framework is surrounding an organic cation acting as a template, and metal-organic frameworks which crystal structures are constructed from metal nodes or clusters linked by organic bridges. Here we present the summary of the work carried out in hybrid vanadates constructed from extended metal-organic arrays. The crystal structures are systematically described and classified according to the dimensionality of the inorganic and metal-organic frameworks. Finally, the magnetic, thermal and catalytic properties of different structural archetypes are discussed.
    CrystEngComm 09/2014; 16(45). DOI:10.1039/C4CE00532E · 4.03 Impact Factor
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    ABSTRACT: Solid coordination frameworks (SCF) are crystalline materials based on connections between metal ions through organic ligands. In this sense, combination of polycarboxylate anions and dipyridyl ligands is an effective strategy to produce extended structures. In this context, this work is focused on two novel CuII-based SCFs exhibiting PDC (2,5-pyridinedicarboxylate) and bpe (1,2-di(4-pyridyl)ethylene): Cu2[(PDC)2(bpe)(H2O)2]•3H2O•DMF (1), and Cu[(PDC)(bpe)0.5(H2O)]•2H2O (2), where DMF is dimethylformamide. Both compounds were synthesized by slow evaporation, and their crystal structures were determined by X-ray diffraction. Further structural, thermal and magnetic characterization was carried out by means of IR, TG/DTG, DTA analysis, EPR, and measurements of the magnetic susceptibility. The crystallographic analysis revealed that compounds 1 and 2 can be described as herringbone-type layers formed by helicoidal Cu-PDC-Cu chains connected through bpe ligands. Solvent molecules are crystallized between the layers, providing the inter-layer connections through hydrogen bonds. Differences between both compounds are attributable to those solvent molecules, being indicative of the flexibility of this type of SCFs. On the other hand, due to the variety of structures found in literature that have been described as “herringbone arrays”, this work also presents a crystallochemical study based on them. The study considers stoichiometry and structural parameters leading to the identification of two types of herringbone arrays depending on the number of connections for the metal nodes (i.e. 3-and 4-connected).
    CrystEngComm 07/2014; 16(37). DOI:10.1039/C4CE00989D · 4.03 Impact Factor
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    ABSTRACT: The structure, thermal stability, morphology and ion conductivity of titanium perovskites with the general formula Li(3x)Ln(2/3-x)TiO(3) (Ln=rare earth element; 3x=0.30) are studied in the context of their possible use as solid electrolyte materials for lithium ion batteries. Materials are prepared by a glycine nitrate method using different sintering treatments, with a cation-disorder-induced structural transition from tetragonal to cubic symmetry, and are detected as quenching temperature increases. SEM images show that the average grain size increases with increasing sintering temperature and time. Slightly higher bulk conductivity values have been observed for quenched samples sintered at high temperature. Bulk conductivity decreases with the lanthanide ion size. A slight conductivity enhancement, always limited by grain boundaries, is observed for longer sintering times. TDX measurements of the electrolyte/cathode mixtures also show a good stability of the electrolytes in the temperature range of 30-1100 degrees C.
    Ceramics International 07/2014; 40(6):8761-8768. DOI:10.1016/j.ceramint.2014.01.097 · 2.61 Impact Factor
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    ABSTRACT: Los sistemas metaloporfirínicos son piezas clave en el engranaje de la vida, debido a las propiedades bioquímicas, enzimáticas y fotoquímicas que desempeña el macrociclo tetrapirrólico presente en las porfirinas . Las distorsiones que presentan estos macrociclos porfirínicos son biológicamente relevantes, y tienen influencia en diferentes propiedades químicas y físicas en este tipo de compuestos. En este sentido, se ha utilizado el programa NSD para analizar la distorsión que presentan los anillos tetrapirrólicos fuera del plano y relacionarla con diferentes parámetros estructurales, característicos en este tipo de compuestos. En el trabajo que aquí se muestra se han analizado MOFs metaloporfirínicos tanto monodimensionales (1D) como bidimensionales (2D) que se han obtenido mediante síntesis hidrotermal. De esta manera, los compuestos estudiados presentan las fórmulas: [CoTPP(bipy)]•([CoTPP])0.22•(TPP)0.78, [CoTPPS0.5(bipy)(H2O)2]•6H2O, [Mn3TCPP(H2O)4]•EtOH•2DMF y [MnTCPP]•nDMF donde TPP: meso-tetra-4-fenilporfirina, TPPS: meso-tetra-4-sulfonatofenilporfirina, TCPP: meso-tetra-4-carboxifenilporfirina, bipy: 4,4´-bipiridina y DMF: N,N-dimetilformamida, para los que se ha podido establecer una relación entre la distorsión que presenta el macrociclo tetrapirrólico y diferentes ángulos, distancias y otros parámetros estructurales.
    XXIV Simposio del GE3C - Cristalografía y Sostenibilidad, Bilbao - Vizcaya (Spain); 06/2014
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    ABSTRACT: Mientras que los biosistemas metaloporfirínicos operan en disolución, la preparación de materiales cristalinos basados en estos macrociclos, viene condicionada por la obtención de entidades supramoleculares; la cual puede ser abordada mediante diferentes estrategias de diseño sintético. En este sentido, una de las estrategias destacables consiste en el uso de porfirinas como la TCPP (meso-tetra-4-carboxifenilporfirina), que se caracterizan por poseer ligandos carboxílicos externos que favorecen el autoensamblaje de las unidades metaloporfirínicas. En este contexto, nuestro grupo de investigación está trabajando con diferentes combinaciones de ligandos orgánicos y metaloporfirinas y el trabajo que aquí se presenta corresponde al compuesto [Mn3(TCPP)(H2O)4]•(DMF)2(EtOH), donde DMF es N,N'-dimetilformamida. El compuesto objeto de estudio se ha obtenido por síntesis solvotermal. Su estructura cristalina está formada por capas (Fig. 1) cuya interconexión mediante enlaces de hidrógeno da lugar a un entramado 3D supramolecular. Los grandes canales que presenta el compuesto, con escasos precedentes en la bibliografía, hacen del mismo un candidato de interés para el estudio de sus posibles aplicaciones en almacenamiento de gases y catálisis.
    QIES14 (16º Reunión Bienal del Grupo Especializado de Química Inorgánica de la RSEQ - 10º Reunión Bienal del Grupo Especializado de Química del Estado Sólido), Cabo de Gata - Almería (Spain); 06/2014
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    ABSTRACT: The importance of crystal growth in Crystallography must be underlined, as it results in the Bravais lattice, which “contains” all the characteristics of the crystalline arrangement. In this sense, it is worth noticing that the principle of maximum space filling in crystal structures can produce outstanding phenomena like interpenetrated frameworks. However, in most of the cases, the space filling requirement involves the significant role of solvents in dissolution-started crystallization processes. In fact, in these the cases, solvents provide the Van der Waals forces driving the crystal growth, where those little molecules are strategically packed to stabilize the network. Solvent molecules can also complete coordination spheres around metal ions in coordination compounds-based crystalline solids. Aspects related to the role of solvents are especially remarkable in porous compounds since, in many cases, the cavities contain solvent molecules. On the other hand, crystal growth has a direct influence on the morphology of the crystals. Additionally, crystallisation helpers can be determinative on crucial aspects such as the crystal size, as this characteristic influences the diffraction measurements, and, therefore, the structural refinement. Thus, this work is focused on the compound Cu24(BDC)24(DMF)14(H2O)10•(H2O)(DMF)2, acronym (Cu24BDC), where BDC is 1,3-benzenedicarboxilate and DMF is N,N-dimethylformamide, consisting of a twelve-dimer cluster units, exhibiting a molecule of water in the center of the as-produced cavities. This compound has been obtained by means of two different synthetic routes yielding crystals with different morphologies. One of the routes involves the use of a metalloporphyrin (Protoporhyrin IX) and produces much bigger crystals than the route without the crystallisation helper. On the other hand, the structural characteristics of Cu24BDC have been compared to the ones of similar clusters found in literature as a-MOP-1 and c-MOP-1 (Eddaoudi et al., 2001, Li & Zhou, 2010) compounds. This comparison reveals the significant influence of solvents on the crystallisation pattern.
    International School of Crystallization, Granada; 05/2014
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    ABSTRACT: Three new fluorinated mixed valence Fe(II)–Fe(III) phosphites were synthesized by employing mild hydrothermal conditions. (H4baepn)0.5[FeIII2.3FeII1.7(H2O)2(HPO3)4−(x+y)(HPO4)x(PO4)yF4] (x [similar, equals] 0.13, y [similar, equals] 0.3) (1) (baepn = N,N′-bis(2-aminoethyl)-1,3-propanediamine (C7N4H20)) and the Co(II)-substituted phase with the formula (H4baepn)0.5[FeIII2.0FeII0.71CoII1.29(H2O)2(HPO3)4−x(HPO4)xF4] (x [similar, equals] 0.38) (2) were studied by single crystal X-ray diffraction. The phase with the major content of Co(II), (H4baepn)0.5[FeIII2.0FeII0.62CoII1.38(H2O)2(HPO3)4−x(HPO4)xF4] (x [similar, equals] 0.38) (3) was obtained as a polycrystalline powder and studied by Rietveld refinement by using the structural model of 2. These compounds were characterized by ICP-Q-MS, thermogravimetric and thermodiffractometric analyses, and XPS, IR, UV/vis and Mössbauer spectroscopy. The single crystal data indicate that phases 1 and 2 crystallize in the P21/c space group with lattice parameters a = 13.6808(4), b = 12.6340(2), c = 12.7830(3) Å and β = 116.983(4)° for 1 and a = 13.6823(4), b = 12.6063(3), c = 12.7535(4) Å and β = 116.988(4)° for 2, with Z = 4. The reciprocal space of 1 shows satellite reflections with a modulation wavevector q = 0.284(2)a* which indicate an incommensurate long-range order. The average structure of these compounds is built up by a 3D lattice constructed by inorganic layers of Fe(III) chains and Fe(II) and Co(II) dimers joined by phosphite groups partially substituted by HPO4 and PO4 tetrahedral groups. These anionic layers stack along the [100] direction encapsulating linear tetramines in eight-membered open channels involving host–guest interactions. Magnetic measurements of 1 and 3 showed antiferromagnetic coupling as the major interactions, exhibiting a weak ferromagnetic component together with a spin glass transition at low temperature in the case of 1. Heat capacity measurements showed a small anomaly at 20.5 K for 1 and a sharp magnetic peak at 28 K for 3. Unexpectedly, the small anomaly observed in 1 increased with the magnetic field and became better defined.
    CrystEngComm 05/2014; 16(27):6066-6079. DOI:10.1039/C4CE00264D · 4.03 Impact Factor

Publication Stats

4k Citations
924.62 Total Impact Points


  • 1985–2015
    • Universidad del País Vasco / Euskal Herriko Unibertsitatea
      • • Facultad de Ciencia y Tecnología
      • • Mineralogy and Petrology
      • • Organic Chemistry I
      • • Inorganic Chemistry
      Leioa, Basque Country, Spain
  • 2007
    • University of Castilla-La Mancha
      Ciudad Real, Castille-La Mancha, Spain
  • 1995–1997
    • Universität Ulm
      Ulm, Baden-Württemberg, Germany
  • 1990
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France