Staff directory

Publications

2017

  • Composite Salt in Porous Metal-Organic Frameworks for Adsorption Heat Transformation

    Garzón-Tovar L., Pérez-Carvajal J., Imaz I., Maspoch D. Advanced Functional Materials; 27 (21, 1606424) 2017. 10.1002/adfm.201606424.

    Adsorptive heat transformation systems such as adsorption thermal batteries and chillers can provide space heating and cooling in a more environmental friendly way. However, their use is still hindered by their relatively poor performances and large sizes due to the limited properties of solid adsorbents. Here, the spray-drying continuous-flow synthesis of a new type of solid adsorbents that results from combining metal-organic frameworks (MOFs), such as UiO-66, and hygroscopic salts, such as CaCl2 has been reported. These adsorbents, commonly named as composite salt in porous matrix (CSPM) materials, allow improving the water uptake capabilities of MOFs while preventing their dissolution in the water adsorbed; a common characteristic of these salts due to the deliquescence effect. It is anticipated that MOF-based CSPMs, in which the percentage of salt can be tuned, are promising candidates for thermal batteries and chillers. In these applications, it is showed that a CSPM made of UiO-66 and CaCl2 (38% w/w) exhibits a heat storage capacity of 367 kJ kg−1, whereas a second CSPM made of UiO-66 and CaCl2 (53% w/w) shows a specific cooling power of 631 W kg−1 and a coefficient of performance of 0.83, comparable to the best solid adsorbents reported so far. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Continuous One-Step Synthesis of Porous M-XF6-Based Metal-Organic and Hydrogen-Bonded Frameworks

    Guillerm V., Garzón-Tovar L., Yazdi A., Imaz I., Juanhuix J., Maspoch D. Chemistry - A European Journal; 23 (28): 6829 - 6835. 2017. 10.1002/chem.201605507.

    Metal-organic frameworks (MOFs) built up from connecting M-XF6 pillars through N-donor ligands are among the most attractive adsorbents and separating agents for CO2 and hydrocarbons today. The continuous, one-step spray-drying synthesis of several members of this isoreticular MOF family varying the anionic pillar (XF6=[SiF6]2− and [TiF6]2−), the N-donor organic ligand (pyrazine and 4,4′-bipyridine) and the metal ion (M=Co, Cu and Zn) is demonstrated here. This synthetic method allows them to be obtained in the form of spherical superstructures assembled from nanosized crystals. As confirmed by CO2 and N2 sorption studies, most of the M-XF6-based MOFs synthesised through spray-drying can be considered “ready-to-use” sorbents as they do not need additional purification and time consuming solvent exchange steps to show comparable porosity and sorption properties with the bulk/single-crystal analogues. Stability tests of nanosized M-SiF6-based MOFs confirm their low stability in most solvents, including water and DMF, highlighting the importance of protecting them once synthesised. Finally, for the first time it was shown that the spray-drying method can also be used to assemble hydrogen-bonded open networks, as evidenced by the synthesis of MPM-1-TIFSIX. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Core-shell Au/CeO2 nanoparticles supported in UiO-66 beads exhibiting full CO conversion at 100 °c

    Yazdi A., Abo Markeb A., Garzón-Tovar L., Patarroyo J., Moral-Vico J., Alonso A., Sánchez A., Bastus N., Imaz I., Font X., Puntes V., Maspoch D. Journal of Materials Chemistry A; 5 (27): 13966 - 13970. 2017. 10.1039/c7ta03006a.

    Hybrid core-shell Au/CeO2 nanoparticles (NPs) dispersed in UiO-66 shaped into microspherical beads are created using the spray-drying continuous-flow method. The combined catalytic properties of nanocrystalline CeO2 and Au in a single particle and the support and protective function of porous UiO-66 beads make the resulting composites show good performances as catalysts for CO oxidation (T50 = 72 °C; T100 = 100 °C) and recyclability. © 2017 The Royal Society of Chemistry.


  • Leucine zipper motif inspiration: A two-dimensional leucine Velcro-like array in peptide coordination polymers generates hydrophobicity

    Rodríguez-Hermida S., Evangelio E., Rubio-Martínez M., Imaz I., Verdaguer A., Juanhuix J., Maspoch D. Dalton Transactions; 46 (34): 11166 - 11170. 2017. 10.1039/c7dt02153d.

    Here, we show that the well-known hydrophobic leucine (Leu) zipper motif (also known as the coiled-coil or Leu scissors motif), typically found in proteins, can be used as a source of inspiration in coordination polymers built from Leu-containing dipeptides or tripeptides. We demonstrate that this motif can be extended to form Velcro-like layers of Leu, and that the hydrophobicity of these layers is transferred to coordination polymers, thereby enabling the development of a new type of hydrophobic materials. © 2017 The Royal Society of Chemistry.


  • Spray drying for making covalent chemistry: Postsynthetic modification of metal-organic frameworks

    Garzón-Tovar L., Rodríguez-Hermida S., Imaz I., Maspoch D. Journal of the American Chemical Society; 139 (2): 897 - 903. 2017. 10.1021/jacs.6b11240.

    Covalent postsynthetic modification (PSM) of metal-organic frameworks (MOFs) has attracted much attention due to the possibility of tailoring the properties of these porous materials. Schiff-base condensation betwecn an amine and an aldehyde is one of the most common reactions in the PSM of MOFs. Here, we report the use of the spray drying technique to perform this class of organic reactions, either betwecn discrete organic molecules or on the pore surfaces of MOFs, in a very fast (1-2 s) and continuous way. Using spray drying, we show the PSM of two MOFs, the amine-terminated UiO-66-NH2 and the aldehyde-terminated ZIF-90, achieving conversion efficiencies up to 20 and 42%, respectively. Moreover, we demonstrate that it can also be used to postsynthetically cross-link the aldehyde groups of ZIF-90 using a diamine molecule with a conversion efficiency of 70%. © 2017 American Chemical Society.


  • Systematic study of the impact of MOF densification into tablets on textural and mechanical properties

    Dhainaut J., Avci-Camur C., Troyano J., Legrand A., Canivet J., Imaz I., Maspoch D., Reinsch H., Farrusseng D. CrystEngComm; 19 (29): 4211 - 4218. 2017. 10.1039/c7ce00338b.

    Four different metal-organic framework powders (UiO-66, UiO-66-NH2, UiO-67, and HKUST-1) were shaped into tablets. The effect of the applied pressure on porous properties, mechanical resistance and tablet bulk density is reported. We observe a linear relationship between densification and tensile strength for all four studied MOFs, with the slope being MOF-dependent. We also report conditions for improving significantly the volumetric uptake. Finally, we evaluated our tablets' stability over time in the presence of moisture. © 2017 The Royal Society of Chemistry.


2016

  • A First Cyclodextrin-Transition Metal Coordination Polymer

    Xu H., Rodríguez-Hermida S., Pérez-Carvajal J., Juanhuix J., Imaz I., Maspoch D. Crystal Growth and Design; 16 (10): 5598 - 5602. 2016. 10.1021/acs.cgd.6b01115.

    The synthesis, X-ray crystallographic structure, and water uptake measurements of the first coordination polymer made of a cyclodextrin and a transition metal ion (in this case, Cu2+) are shown. This coordination polymer is made by connecting paddle-wheel Cu2+ units through a γ-cyclodextrin functionalized with eight carboxylate groups, is stable in water, and shows selective water-induced reversible structural transformations. © 2016 American Chemical Society.


  • Application of metal and metal oxide nanoparticles at MOFs

    Falcaro P., Ricco R., Yazdi A., Imaz I., Furukawa S., Maspoch D., Ameloot R., Evans J.D., Doonan C.J. Coordination Chemistry Reviews; 307: 237 - 254. 2016. 10.1016/j.ccr.2015.08.002. IF: 12.994

    Composites based on Metal-Organic Frameworks (MOFs) are an emerging class of porous materials that have been shown to possess unique functional properties. Nanoparticles at MOFs composites combine the tailorable porosity of MOFs with the versatile functionality of metal or metaloxide nanoparticles. A wide range of nanoparticles at MOFs have been synthesised and their performance characteristics assessed in molecular adsorption and separation, catalysis, sensing, optics, sequestration of pollutants, drug delivery, and renewable energy. This review covers the main research areas where nanoparticles at MOFs have been strategically applied and highlights the scientific challenges to be considered for their continuing development. © 2015 Published by Elsevier B.V.


  • Enhanced Spin Tunneling in a Molecular Magnet Mixed with a Superconductor

    Tejada J., Zarzuela R., García-Santiago A., Imaz I., Espin J., Maspoch D., Chudnovsky E.M. Journal of Superconductivity and Novel Magnetism; 29 (5): 1133 - 1137. 2016. 10.1007/s10948-016-3474-6.

    We report characterization and magnetic studies of mixtures of micrometer-size ribbons of Mn12 acetate and micrometer-size particles of YBaCuO superconductor. Extremely narrow zero-field spin-tunneling resonance has been observed in the mixtures, pointing to the absence of the inhomogeneous dipolar broadening. It is attributed to the screening of the internal magnetic fields in the magnetic particles by Meissner currents flowing between superconducting grains surrounding the particles. © 2016, Springer Science+Business Media New York.


  • Freezing the Nonclassical Crystal Growth of a Coordination Polymer Using Controlled Dynamic Gradients

    Rubio-Martinez M., Imaz I., Domingo N., Abrishamkar A., Mayor T.S., Rossi R.M., Carbonell C., deMello A.J., Amabilino D.B., Maspoch D., Puigmartí-Luis J. Advanced Materials; : 8150 - 8155. 2016. 10.1002/adma.201506462.

    An experiment was conducted to show that diffusion-limited and kinetically controlled growth regimes occurring in microfluidic devices can provide valuable insights into crystallization processes. The microfluidic channels employed in this study were structured in PDMS master form fabricated by standard photolithographic techniques. Before attaching the cured and structured PDMS mould to a glass coverslip through plasma activation, inlet holes connecting the microfluidic channels were punched with a Biopsy puncher. The cross-sectional dimensions of the microchannels were 50 μm into 50 μm for the four input microchannels, and 250 μm into 50 μm for the main reactor channel. The total length of the main reactor channel was 9 mm. Data were indexed, integrated, and scaled using HKL2000 software. The H atoms were included in theoretical positions but not refined. The low max value was due to the data collection process, which was performed in the BM16 line with only a phi scan. The structure was solved by direct methods using the program SHELXS-97. The AFM results suggest that the early stage isolated seeds organize at a single level and in a perpendicular fashion, leading to the final plate-like crystalline morphologies observed in bulk and at an FFR of 0.1.


  • Hetero-bimetallic paddlewheel clusters in coordination polymers formed by a water-induced single-crystal-to-single-crystal transformation

    Albalad J., Aríñez-Soriano J., Vidal-Gancedo J., Lloveras V., Juanhuix J., Imaz I., Aliaga-Alcalde N., Maspoch D. Chemical Communications; 52 (91): 13397 - 13400. 2016. 10.1039/c6cc07653j.

    Herein we report a water-induced single-crystal to single-crystal transformation that involves the formation of hetero-bimetallic paddlewheel clusters in coordination polymers. Through this transformation, which involves the cleavage and formation of different coordination bonds, two different Cu(ii)-Zn(ii) and Cu(ii)-Ni(ii) paddlewheel units exhibiting a 1:1 metal ratio were created. © 2016 The Royal Society of Chemistry.


  • Influence of the Amide Groups in the CO2/N2 Selectivity of a Series of Isoreticular, Interpenetrated Metal-Organic Frameworks

    Safarifard V., Rodríguez-Hermida S., Guillerm V., Imaz I., Bigdeli M., Tehrani A.A., Juanhuix J., Morsali A., Casco M.E., Silvestre-Albero J., Ramos-Fernandez E.V., Maspoch D. Crystal Growth and Design; 16 (10): 6016 - 6023. 2016. 10.1021/acs.cgd.6b01054.

    Here we report the use of a pillaring strategy for the design and synthesis of three novel amide-functionalized metal-organic frameworks (MOFs), TMUs-22/-23/-24, isoreticular to the recently reported imine-functionalized TMU-6 and TMU-21 MOFs. An extensive study of their CO2 sorption properties and selectivity for CO2 over N2, from single gas sorption isotherms to breakthrough measurements, revealed that not only the incorporation of amide groups but also their accessibility is crucial to obtain enhanced CO2 sorption and CO2/N2 selectivity. Therefore, the MOF with more accessible amide groups (TMU-24) shows a CO2/N2 selectivity value of ca. 10 (as revealed by breakthrough experiments), which is ca. 500% and 700% of the selectivity values observed for the other amide-containing (TMU-22 and TMU-23) and imine-containing (TMU-6 and TMU-21) MOFs. © 2016 American Chemical Society.


  • Introducing asymmetric functionality into MOFs: Via the generation of metallic Janus MOF particles

    Ayala A., Carbonell C., Imaz I., Maspoch D. Chemical Communications; 52 (29): 5096 - 5099. 2016. 10.1039/c6cc01098a.

    Herein we report a versatile methodology for engineering metallic Janus MOF particles based on desymmetrization at interfaces, whereby each MOF particle is partially coated with a desired metal. We demonstrate that it enables the fabrication of homogeneous Janus MOF particles according to the MOF (ZIF-8, UiO-66 or UiO-66-SH), the metal (Au, Co or Pt), the MOF particle size (from the micrometer to the submicrometer regime) and the metal-film thickness (from 5 nm to 50 nm) employed. We anticipate that our strategy could be applied to impart new functionalities to MOFs, including asymmetric functionalization, magnetic-guidance and motorization. © The Royal Society of Chemistry 2016.


  • Narrowing the Zero-Field Tunneling Resonance by Decreasing the Crystal Symmetry of Mn12 Acetate

    Espín J., Zarzuela R., Statuto N., Juanhuix J., Maspoch D., Imaz I., Chudnovsky E., Tejada J. Journal of the American Chemical Society; 138 (29): 9065 - 9068. 2016. 10.1021/jacs.6b05380.

    We report the discovery of a less symmetric crystalline phase of Mn12 acetate, a triclinic phase, resulting from recrystallizing the original tetragonal phase reported by Lis in acetonitrile and toluene. This new phase exhibits the same structure of Mn12 acetate clusters and the same positions of tunneling resonances on the magnetic field as the conventional tetragonal phase. However, the width of the zero-field resonance is at least 1 order of magnitude smaller - can be as low as 50 Oe - indicating very small inhomogeneous broadening due to dipolar and nuclear fields. © 2016 American Chemical Society.


  • pH-Responsive Relaxometric Behaviour of Coordination Polymer Nanoparticles Made of a Stable Macrocyclic Gadolinium Chelate

    Aríñez-Soriano J., Albalad J., Carné-Sánchez A., Bonnet C.S., Busqué F., Lorenzo J., Juanhuix J., Terban M.W., Imaz I., Tóth É., Maspoch D. Chemistry - A European Journal; 22 (37): 13162 - 13170. 2016. 10.1002/chem.201602356.

    Lanthanide-containing nanoscale particles have been widely explored for various biomedical purposes, however, they are often prone to metal leaching. Here we have created a new coordination polymer (CP) by applying, for the first time, a stable GdIIIchelate as building block in order to prevent any fortuitous release of free lanthanide(III) ion. The use of the Gd-DOTA-4AmP complex as a design element in the CP allows not only for enhanced relaxometric properties (maximum r1=16.4 mm−1s−1at 10 MHz), but also for a pH responsiveness (Δr1=108 % between pH 4 and 6.5), beyond the values obtained for the low molecular weight Gd-DOTA-4AmP itself. The CP can be miniaturised to the nanoscale to form colloids that are stable in physiological saline solution and in cell culture media and does not show cytotoxicity. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Single-crystal and humidity-controlled powder diffraction study of the breathing effect in a metal-organic framework upon water adsorption/desorption

    Aríñez-Soriano J., Albalad J., Vila-Parrondo C., Pérez-Carvajal J., Rodríguez-Hermida S., Cabeza A., Juanhuix J., Imaz I., Maspoch D. Chemical Communications; 52 (45): 7229 - 7232. 2016. 10.1039/c6cc02908f.

    Herein we report a study on water adsorption/desorption-triggered single-crystal to single-crystal transformations in a MOF, by single-crystal and humidity-controlled powder X-ray diffraction and water-sorption measurements. We identified a gate-opening effect at a relative humidity of 85% upon water adsorption, and a gate-closure effect at a relative humidity of 55 to 77% upon water desorption. This reversible breathing effect between the "open" and the "closed" structures of the MOF involves the cleavage and formation of several coordination bonds. © 2016 The Royal Society of Chemistry.


  • Switchable Surface Hydrophobicity–Hydrophilicity of a Metal–Organic Framework

    Rodríguez-Hermida S., Tsang M.Y., Vignatti C., Stylianou K.C., Guillerm V., Pérez-Carvajal J., Teixidor F., Viñas C., Choquesillo-Lazarte D., Verdugo-Escamilla C., Peral I., Juanhuix J., Verdaguer A., Imaz I., Maspoch D., Giner Planas J. Angewandte Chemie - International Edition; 55 (52): 16049 - 16053. 2016. 10.1002/anie.201609295.

    Materials with surfaces that can be switched from high/superhydrophobicity to superhydrophilicity are useful for myriad applications. Herein, we report a metal–organic framework (MOF) assembled from ZnIIions, 1,4-benzenedicarboxylate, and a hydrophobic carborane-based linker. The MOF crystal-surface can be switched between hydrophobic and superhydrophilic through a chemical treatment to remove some of the building blocks. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim


  • Two-step synthesis of heterometallic coordination polymers using a polyazamacrocyclic linker

    Aríñez-Soriano J., Albalad J., Pérez-Carvajal J., Imaz I., Busqué F., Juanhuix J., Maspoch D. CrystEngComm; 18 (22): 4196 - 4204. 2016. 10.1039/c5ce02520f.

    A new macrocyclic linker 1,4,7,10-tetraazacyclododecane-1,7-bis(4-acetamidobenzoic)-4,10-diacetic acid (H4L1) was synthesized and characterized. This linker was used to create two heterometallic coordination polymers following a two-step synthesis. This synthesis consisted of first combining this polyazamacrocyclic linker with Ni(ii) or Mn(ii) ions to obtain the corresponding metallomacrocyclic complexes showing non-coordinated carboxylic groups. In a second step, these metallated macrocycles were used as building units to construct two heterometallic Ni(ii)-Zn(ii) and Mn(ii)-Zn(ii) coordination polymers when combined with Zn(ii) ions. In addition, a third Zn(ii)-Zn(ii) coordination polymer could also be synthesized by direct mixing of H4L1 with Zn(ii) ions. Interestingly, the Mn(ii)-Zn(ii) coordination polymer exhibits a reversible type-I "crystal-to-amorphous transformation" upon water sorption/desorption. © The Royal Society of Chemistry.


2015

  • Engineering Homochiral Metal-Organic Frameworks by Spatially Separating 1D Chiral Metal-Peptide Ladders: Tuning the Pore Size for Enantioselective Adsorption

    Stylianou K.C., Gõmez L., Imaz I., Verdugo-Escamilla C., Ribas X., Maspoch D. Chemistry - A European Journal; 21 (28): 9964 - 9969. 2015. 10.1002/chem.201501315.

    The reaction of the chiral dipeptide glycyl-L(S)-glutamate with CoII ions produces chiral ladders that can be used as rigid 1D building units. Spatial separation of these building units with linkers of different lengths allows the engineering of homochiral porous MOFs with enhanced pore sizes, pore volumes, and surface areas. This strategy enables the synthesis of a family of isoreticular MOFs, in which the pore size dictates the enantioselective adsorption of chiral molecules (in terms of their size and enantiomeric excess). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Lanthanide-organic framework nanothermometers prepared by spray-drying

    Wang Z., Ananias D., Carné-Sánchez A., Brites C.D.S., Imaz I., Maspoch D., Rocha J., Carlos L.D. Advanced Functional Materials; 25 (19): 2824 - 2830. 2015. 10.1002/adfm.201500518.

    Accurate, noninvasive, and self-referenced temperature measurements at the submicrometer scale are of great interest, prompted by the ever-growing demands in the fields of nanotechnology and nanomedicine. The thermal dependence of the phosphor's luminescence provides high detection sensitivity and spatial resolution with short acquisition times in, e.g., biological fluids, strong electromagnetic fields, and fast-moving objects. Here, it is shown that nanoparticles of [(Tb0.914Eu0.086)2(PDA)3(H2O)]·2H2O (PDA = 1,4-phenylenediacetic acid), the first lanthanide-organic framework prepared by the spray-drying method, are excellent nanothermometers operating in the solid state in the 10-325 K range (quantum yield of 0.25 at 370 nm, at room temperature). Intriguingly, this system is the most sensitive cryogenic nanothermometer reported so far, combining high sensitivity (up to 5.96 ± 0.04% K-1 at 25 K), reproducibility (in excess of 99%), and low-temperature uncertainty (0.02 K at 25 K). One of the most sensitive cryogenic thermometers (5.96% K-1 at 25 K) reported so far is described, consisting of lanthanide (Tb3+, Eu3+) organic framework nanoparticles prepared by spray-drying, exhibiting an excellent reproducibility (>99%) and low-temperature uncertainty (0.02 K at 25 K). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Optimised room temperature, water-based synthesis of CPO-27-M metal-organic frameworks with high space-time yields

    Garzón-Tovar L., Carné-Sánchez A., Carbonell C., Imaz I., Maspoch D. Journal of Materials Chemistry A; 3 (41): 20819 - 20826. 2015. 10.1039/c5ta04923g.

    The exceptional porosity of Metal-Organic Frameworks (MOFs) could be harnessed for countless practical applications. However, one of the challenges currently precluding the industrial exploitation of these materials is a lack of green methods for their synthesis. Since green synthetic methods obviate the use of organic solvents, they are expected to reduce the production costs, safety hazards and environmental impact typically associated with MOF fabrication. Herein we describe the stepwise optimisation of reaction parameters (pH, reagent concentrations and reaction time) for the room temperature, water-based synthesis of several members of the CPO-27/MOF-74-M series of MOFs, including ones made from Mg(ii), Ni(ii), Co(ii) and Zn(ii) ions. Using this method, we built MOFs with excellent BET surface areas and unprecedented Space-Time Yields (STYs). Employing this approach, we have synthesised CPO-27-M MOFs with record BET surface areas, including 1279 m2 g-1 (CPO-27-Zn), 1351 m2 g-1 (CPO-27-Ni), 1572 m2 g-1 (CPO-27-Co), and 1603 m2 g-1 (CPO-27-Mg). We anticipate that our method could be applied to produce CPO-27-Ni, -Mg, -Co and -Zn with STYs of 44 kg m-3 per day, 191 kg m-3 per day, 1462 kg m-3 per day and a record 18720 kg m-3 per day, respectively. © The Royal Society of Chemistry.


  • Post-Synthetic Anisotropic Wet-Chemical Etching of Colloidal Sodalite ZIF Crystals

    Avci C., Ariñez-Soriano J., Carné-Sánchez A., Guillerm V., Carbonell C., Imaz I., Maspoch D. Angewandte Chemie - International Edition; 54 (48): 14417 - 14421. 2015. 10.1002/anie.201507588.

    Controlling the shape of metal-organic framework (MOF) crystals is important for understanding their crystallization and useful for myriad applications. However, despite the many advances in shaping of inorganic nanoparticles, post-synthetic shape control of MOFs and, in general, molecular crystals remains embryonic. Herein, we report using a simple wet-chemistry process at room temperature to control the anisotropic etching of colloidal ZIF-8 and ZIF-67 crystals. Our work enables uniform reshaping of these porous materials into unprecedented morphologies, including cubic and tetrahedral crystals, and even hollow boxes, by an acid-base reaction and subsequent sequestration of leached metal ions. Etching tests on these ZIFs reveal that etching occurs preferentially in the crystallographic directions richer in metal-ligand bonds; that, along these directions, the etching rate tends to be faster on the crystal surfaces of higher dimensionality; and that the etching can be modulated by adjusting the pH of the etchant solution. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.


  • Protecting metal-organic framework crystals from hydrolytic degradation by spray-dry encapsulating them into polystyrene microspheres

    Carné-Sánchez A., Stylianou K.C., Carbonell C., Naderi M., Imaz I., Maspoch D. Advanced Materials; 27 (5): 869 - 873. 2015. 10.1002/adma.201403827.

    A one-step, alternative, rapid, and scalable spray-drying (SD) synthesis of metal-organic frameworks (MOF)@polymer composites with enhanced hydrolytic stabilities was reported. SD was used to encapsulate preformed MOF crystals in a polymeric matrix to generate microscale MOF@polymer spheres. For proof-of-concept Hong-Kong University of Science and Technology-1 (HKUST-1) was chosen as the water-sensitive MOF, and polystyrene (PS) as the organic polymer. The synthesis of HKUST-1@PS began with preparation of a stable colloidal suspension of HKUST-1 crystals and a solution of PS in dichloromethane (DCM). This mixture was atomized using a two-fluid nozzle. After 40 min of continuous spraying, 1.7 g of a blue powder was recovered. The sample was then washed with ethanol and dried at 120°C under vacuum. This product was analyzed through field-emission scanning electron microscopy (FESEM), which indicated that it comprised smooth microspheres of HKUST-1@PS composites and did not contain any free HKUST-1. X-ray powder diffraction (XRPD) analysis of these spheres revealed a perfect match with the HKUST-1 pattern. The exclusive presence of microspheres and the match in XRPD patterns evidenced that HKUST-1 crystals were indeed entrapped within the polymeric matrix of PS.


  • Resonant spin tunneling in randomly oriented nanospheres of Mn12 acetate

    Lendínez S., Zarzuela R., Tejada J., Terban M.W., Billinge S.J.L., Espin J., Imaz I., Maspoch D., Chudnovsky E.M. Physical Review B - Condensed Matter and Materials Physics; 91 (2, 024404) 2015. 10.1103/PhysRevB.91.024404. IF: 3.736

    We report measurements and theoretical analysis of resonant spin tunneling in randomly oriented nanospheres of a molecular magnet. Amorphous nanospheres of Mn12 acetate have been fabricated and characterized by chemical, infrared, TEM, x-ray, and magnetic methods. Magnetic measurements have revealed sharp tunneling peaks in the field derivative of the magnetization that occur at the typical resonant field values for the Mn12 acetate crystal in the field parallel to the easy axis. Theoretical analysis is provided that explains these observations. We argue that resonant spin tunneling in a molecular magnet can be established in a powder sample, without the need for a single crystal and without aligning the easy magnetization axes of the molecules. This is confirmed by reanalyzing the old data on a powdered sample of nonoriented micron-size crystals of Mn12 acetate. Our findings can greatly simplify the selection of candidates for quantum spin tunneling among newly synthesized molecular magnets. © 2015 American Physical Society.


  • Synthesis, culture medium stability, and in vitro and in vivo zebrafish embryo toxicity of metal-organic framework nanoparticles

    Ruyra A., Yazdi A., Espín J., Carné-Sánchez A., Roher N., Lorenzo J., Imaz I., Maspoch D. Chemistry - A European Journal; 21 (6): 2508 - 2518. 2015. 10.1002/chem.201405380.

    Metal-organic frameworks (MOFs) are among the most attractive porous materials available today. They have garnered much attention for their potential utility in many different areas such as gas storage, separation, catalysis, and biomedicine. However, very little is known about the possible health or environmental risks of these materials. Here, the results of toxicity studies on sixteen representative uncoated MOF nanoparticles (nanoMOFs), which were assessed for cytotoxicity to HepG2 and MCF7 cells in vitro, and for toxicity to zebrafish embryos in vivo, are reported. Interestingly, there is a strong correlation between their in vitro toxicity and their in vivo toxicity. NanoMOFs were ranked according to their respective in vivo toxicity (in terms of the amount and severity of phenotypic changes observed in the treated zebrafish embryos), which varied widely. Altogether these results show different levels of toxicity of these materials; however, leaching of solubilized metal ions plays a main role. © 2015 Wiley-VCH Verlag GmbH & Co. KGaA.


  • Two New Adenine-Based Co(II) Coordination Polymers: Synthesis, Crystal Structure, Coordination Modes, and Reversible Hydrochromic Behavior

    Burneo I., Stylianou K.C., Rodríguez-Hermida S., Juanhuix J., Fontrodona X., Imaz I., Maspoch D. Crystal Growth and Design; 15 (7): 3182 - 3189. 2015. 10.1021/acs.cgd.5b00218.

    We report the synthesis of two new three-dimensional coordination polymers (CPs) based on Co(II), adenine, and aromatic tetracarboxylate linkers. Adenine exhibits bidentate binding modes in both CPs, coordinating through the N3 and N9 sites in a first compact CP and through the more rare N3 and N7 sites in a second open, flexible, and H2O-responsive CP. These differences together with an analysis of the extended coordination structures made of adenine reported in the Cambridge Structural Database illustrate the rich coordination versatility of adenine as a building block for CPs. Although the latter CP is nonporous to N2 or CO2, it shows a reversible and detectable color change from pink to purple, and vice versa, upon hydration and dehydration, respectively. (Graph Presented). © 2015 American Chemical Society.


2014

  • Localized, stepwise template growth of functional nanowires from an amino acid-supported framework in a microfluidic chip

    Puigmartí-Luis, J.; Rubio-Martínez, M.; Imaz, I.; Cvetkovic, B.Z.; Abad, L.; Pérez Del Pino, A.; Maspoch, D.; Amabilino, D.B. ACS Nano; 8 (1): 818 - 826. 2014. 10.1021/nn4054864. IF: 12.033


  • Metal-organic frameworks: From molecules/metal ions to crystals to superstructures

    Carné-Sánchez, A.; Imaz, I.; Stylianou, K.C.; Maspoch, D. Chemistry - A European Journal; 20 (18): 5192 - 5201. 2014. 10.1002/chem.201304529. IF: 5.696


  • Sponge-like molecular cage for purification of fullerenes

    García-Simón, C.; Garcia-Borràs, M.; Gómez, L.; Parella, T.; Osuna, S.; Juanhuix, J.; Imaz, I.; Maspoch, D.; Costas, M.; Ribas, X. Nature Communications; 2014. 10.1038/ncomms6557. IF: 10.742


  • The influence of the enantiomeric ratio of an organic ligand on the structure and chirality of metal-organic frameworks

    Burneo, I.; Stylianou, K.C.; Imaz, I.; Maspoch, D. Chemical Communications; 50 (89): 13829 - 13832. 2014. 10.1039/c4cc06190j. IF: 6.718


2013

  • A spray-drying strategy for synthesis of nanoscale metal-organic frameworks and their assembly into hollow superstructures

    Carné-Sánchez, A.; Imaz, I.; Cano-Sarabia, M.; Maspoch, D. Nature Chemistry; 5: 203 - 211. 2013. 10.1038/nchem.1569. IF: 21.757


  • Dual-Template synthesis of one-dimensional conductive nanoparticle superstructures from coordination metal-peptide polymer crystals

    Rubio-Martínez, M.; Puigmartí-Luis, J.; Imaz, I.; Dittrich, P.S.; Maspoch, D. Small; 9 (24): 4160 - 4167. 2013. 10.1002/smll.201301338. IF: 7.823


  • Extended H-bond networks based on guanidinium H-donors and [Zr(A) 4]4- H-acceptor units: Modulation of the assemblage and guest accessible volume by chemical design (A = oxalate, dihydrobenzoquinonate, chloranilate)

    Mouchaham, G.; Roques, N.; Duhayon, C.; Imaz, I.; Sutter, J.-P. New Journal of Chemistry; 37: 3476 - 3487. 2013. 10.1039/c3nj00520h. IF: 2.966


  • Femtolitre chemistry assisted by microfluidic pen lithography

    Carbonell, C. ; Stylianou, K. C. ; Hernando, J.; Evangelio, E. ; Barnett, S. A.; Nettikadan, S. ; Imaz, I.; Maspoch, D. Nature Communications; 4: 2173. 2013. 10.1038/ncomms3173. IF: 10.015


  • Relaxometry studies of a highly stable nanoscale metal-organic framework made of Cu(II), Gd(III), and the macrocyclic DOTP

    Carné-Sánchez, A.; Bonnet, C.S.; Imaz, I.; Lorenzo, J.; Tóth, E.; Maspoch, D. Journal of the American Chemical Society; 135 (47): 17711 - 17714. 2013. 10.1021/ja4094378. IF: 10.677


  • Self-assembled tetragonal prismatic molecular cage highly selective for anionic Ï€ guests

    García-Simón, C.; Garcia-Borrà s, M.; Gómez, L.; Garcia-Bosch, I.; Osuna, S.; Swart, M.; Luis, J.M.; Rovira, C.; Almeida, M.; Imaz, I.; Maspoch, D.; Costas, M.; Ribas, X. Chemistry - A European Journal; 19: 1445 - 1456. 2013. 10.1002/chem.201203376. IF: 5.831


  • Tetradihydrobenzoquinonate and tetrachloranilate Zr(IV) complexes: Single-crystal-to-single-crystal phase transition and open-framework behavior for K4Zr(DBQ)4

    Imaz, I.; Mouchaham, G.; Roques, N.; Brandès, S.; Sutter, J.-P. Inorganic Chemistry; 52: 11237 - 11243. 2013. 10.1021/ic401474f. IF: 4.593


2012

  • Three-dimensional porous metal-radical frameworks based on triphenylmethyl radicals

    Datcu, A.; Roques, N.; Jubera, V.; Maspoch, D.; Fontrodona, X.; Wurst, K.; Imaz, I.; Mouchaham, G.; Sutter, J.-P.; Rovira, C.; Veciana, J. Chemistry - A European Journal; 18: 152 - 162. 2012. 10.1002/chem.201102278.


2011

  • Controlling the length and location of in situ formed nanowires by means of microfluidic tools

    Kuhn, P.; Puigmartí-Luis, J.; Imaz, I.; Maspoch, D.; Dittrich, P.S. Lab on a Chip - Miniaturisation for Chemistry and Biology; 11: 753 - 757. 2011. 10.1039/c0lc00270d.


  • Coordination polymer nanofibers generated by microfluidic synthesis

    Puigmartí-Luis, J.; Rubio-Martínez, M.; Hartfelder, U.; Imaz, I.; Maspoch, D.; Dittrich, P.S. Journal of the American Chemical Society; 133: 4216 - 4219. 2011. 10.1021/ja110834j.


  • Metal-biomolecule frameworks (MBioFs)

    Imaz, I.; Rubio-Martínez, M.; An, J.; Solé-Font, I.; Rosi, N.L.; Maspoch, D. Chemical Communications; 47: 7287 - 7302. 2011. 10.1039/c1cc11202c.


  • Nanoscale metal-organic materials

    Carné, A.; Carbonell, C.; Imaz, I.; Maspoch, D. Chemical Society Reviews; 40: 291 - 305. 2011. 10.1039/c0cs00042f.


  • Single-crystal metal-organic framework arrays

    Carbonell, C.; Imaz, I.; Maspoch, D. Journal of the American Chemical Society; 133: 2144 - 2147. 2011. 10.1021/ja2002428.


  • Three-dimensional open-frameworks based on LnIII ions and open-/closed-Shell PTM ligands: Synthesis, structure, luminescence, and magnetic properties

    Datcu, A.; Roques, N.; Jubera, V.; Imaz, I.; Maspoch, D.; Sutter, J.-P.; Rovira, C.; Veciana, J. Chemistry - A European Journal; 17: 3644 - 3656. 2011. 10.1002/chem.201002993.


2010

  • Coordination polymer particles as potential drug delivery systems

    Imaz, I.; Rubio-Martínez, M.; García-Fernández, L.; García, F.; Ruiz-Molina, D.; Hernando, J.; Puntes, V.; Maspoch, D. Chemical Communications; 46: 4737 - 4739. 2010. 10.1039/c003084h.


  • Effect of crystalline disorder on quantum tunneling in the single-molecule magnet Mn12 benzoate

    Carbonera, C.; Luis, F.; Campo, J.; Sánchez-Marcos, J.; Camón, A.; Chaboy, J.; Ruiz-Molina, D.; Imaz, I.; Van Slageren, J.; Dengler, S.; González, M. Physical Review B - Condensed Matter and Materials Physics; 81: 014427-1 - 014427-10. 2010. 10.1103/PhysRevB.81.014427.


  • Formation of metal-bioorganic nanofibres on a microchip

    Hartfelder, U.; Puigmartí-Luis, J.; Imaz, I.; Maspoch, D.; Dittrich, P.S. European Cells and Materials; 20: 103. 2010. .


  • Towards nanowire sensors on a microfluidic platform: In-situ formation, positioning and sizing of nanowire bundles

    Kuhn, P.; Puigmartí-Luis, J.; Imaz, I.; Maspoch, D.; Dittrich, P.S. European Cells and Materials; 20: 58. 2010. .


2009

  • Amino acid based metal-organic nanofibers

    Imaz, I.; Rubio-Martínez, M.; Saletra, W.J.; Amabilino, D.B.; Maspoch, D. Journal of the American Chemical Society; 131: 18222 - 18223. 2009. 10.1021/ja908721t.


  • Metal-organic spheres as functional systems for guest encapsulation

    Imaz, I.; Hernando, J.; Ruiz-Molina, D.; Maspoch, D. Angewandte Chemie - International Edition; 48: 2325 - 2329. 2009. .


2008

  • Catechol derivatives as fluorescent chemosensors for wide-range pH detection

    Evangelio, E.; Hernando, J.; Imaz, I.; Bardají, G.G.; Alibés, R.; Busqué, F.; Ruiz-Molina, D. Chemistry - A European Journal; 14: 9754 - 9763. 2008. 10.1002/chem.200800722.


  • Magnetic behaviour of Mn12 single-molecule magnet nanospheres

    Carbonera, C.; Imaz, I.; Maspoch, D.; Ruiz-Molina, D.; Luis, F. Inorganica Chimica Acta; 361: 3951 - 3956. 2008. 10.1016/j.ica.2008.03.037.


  • Nanosized trigonal prismatic and antiprismatic CuII coordination cages based on tricarboxylate linker

    Anna Company; Nans Roques; Mireia Güell; Veronica Mugnaini; Laura Gómez; Inhar Imaz; Angela Datcu; Miquel Solà; Josep M. Luis; Jaume Veciana; Xavi Ribas and Miquel Costas Dalton Transactions; 1: 1679 - 1682. 2008. 10.1039/B800027C .


  • Octanuclear {Co6W2} aggregate versus mixed valence {Co}3 cluster in the assembling of Co(phen)2Cl2 (phen = 1,10-phenanthroline) with octacyano metallates: a case of non-isotructurality between {W(CN)8}4- and {Nb(CN)8}4-

    Thengarai S. Venkatakrishnan; Inhar Imaz; Jean-Pascal Sutter Inorganica Chimica Acta; 361: 3710 - 3713. 2008. 10.1016/j.ica.2008.03.104.


  • Single-molecule magnet behaviour in metal-organic nanospheres generated by simple precipitation of Mn12O12 clusters

    Imaz, I.; Luis, F.; Carbonera, C.; Ruiz-Molina, D.; Maspoch, D. Chemical Communications; : 1202 - 1204. 2008. 10.1039/b716071b.


  • Synthesis and structure of iron (III) and iron (II) complexes in S(4)P(2) environment created by Diethyldithiocarbamate and 1,2-bis(diphenylphosphino)ethane chelation: Investigation of the electronic structure of the complexes by Mossbauer and magnetic

    Tanmay K. Jana; Dhurjati P. Kumar; Rabindranath Pradhan; Subhajit Dindaa; Pradip N. Ghosh; Corine Simonnet; Jérome Marrot; Inhar Imaz; Alain Wattiaux; Léopold Fournès; Jean-Pascal Sutter; Francis Sécheresse; Ramgopal Bhattacharyya Inorganica Chimica Acta; 362: 3583 - 3594. 2008. 10.1016/j.ica.2009.04.007.


  • Valence-tautomeric metal-organic nanoparticles

    Imaz, I.; Maspoch, D.; Rodríguez-Blanco, C.; Pérez-Falcón, J.M.; Campo, J.; Ruiz-Molina, D. Angewandte Chemie - International Edition; 47: 1857 - 1860. 2008. 10.1002/anie.200705263.


2007

  • New insights into the thermal stability of Mn12 clusters: The case of complex [Mn12O12(O2CCCH) 16(H2O)4]·3H2O and its thermolysis derived [Mn3(O2CCCH)6(H 2O)4]·2H2O complex

    Gómez-Segura, J.; Campo, J.; Imaz, I.; Wurst, K.; Veciana, J.; Gerbier, P.; Ruiz-Molina, D. Dalton Transactions; : 2450 - 2456. 2007. 10.1039/b700298j.


  • New insights into the thermal stability of Mn12 clusters: The case of complex [Mn12O12(O2CC[triple bond, length as m-dash]CH)16(H2O)4]·3H2O and its thermolysis derived [Mn3(O2CC[triple bond, length as m-dash]CH)6(H2O)4]·2H2O complex

    Jordi Gómez-Segura; Javier Campo; Inhar Imaz; Klaus Wurst; Jaume Veciana; Philippe Gerbiere; Daniel Ruiz-Molina Dalton Transactions; 2007. .


  • New insights into the thermal stability of Mn12clusters: The case of complex [Mn12O12(O2CCºCH)16 (H2O)4 ]*3H2O and its thermolysis derived [Mn3(O2CCºCH)6(H2O)4]*2H2O complex

    Gómez-Segura J.; J. Campo; I. Imaz; K. Wurst; J. Veciana; P. Gerbier; D. Ruiz-Molina Journal of the Chemical Society - Dalton Transactions; 31: 2450 - 2456. 2007. .


2006

  • A new hexaferrocene complex with a [M3(ο3-O)] 7+ core

    Mereacre, V.; Nakano, M.; Gómez-Segura, J.; Imaz, I.; Sporer, C.; Wurst, K.; Veciana, J.; Turta, C.; Ruiz-Molina, D.; Jaitner, P. Inorganic Chemistry; 45: 10443 - 10445. 2006. 10.1021/ic061322s.