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Multidrug-resistant bacteria have become a global health problem for which new prophylactic strategies are now needed, including surface-coatings for hospital spaces and medical equipment. This work reports the preparation and functional validation of a metal-organic framework (MOF) based composite for the triggered controlled release of iodine, an antimicrobial element that does not generate resistance. It comprises beads of the iodophilic MOF UiO-66 containing encapsulated gold nanorods (AuNRs) coated with a silica shell. Irradiation of the AuNRs with near-infrared light (NIR) provokes a photothermal effect and the resultant heat actively liberates the iodine. After validating the performance of this composite, it is integrated into a polymer for the development of antibacterial films. This work assesses the adsorption of iodine into these composite films, as well as its passive long-term release and active light-triggered. Finally, this work validates the antibacterial activity of the composite films in vitro against gram-positive and gram-negative bacteria. The findings will surely inform the development of new prophylactic treatments., This work was supported by the Spanish MINECO (project RTI2018-095622-B-I00, RTI2018-099965-B-I00, AEI/FEDER, UE), the Catalan AGAUR (project 2017 SGR 238, 2017 SGR 1431), and the ERC, under the EU-FP7 (ERC-Co 615954). It was also funded by the CERCA Program/Generalitat de Catalunya. ICN2 is supported by the Severo Ochoa program from the Spanish MINECO (Grant No. SEV-2017-0706). X.H. thanks the China Scholarship Council (CSC) for scholarship support (201804910551). M.B. thanks the Polish National Agency for Academic Exchange (contract no. PPN/BEK/2018/1/00094/U/00001). O.M. acknowledges financial support from the Spanish Ministry of Science and Innovation (MICINN) by FPI fellowship, resolved by the Agencia Estatal de Investigación (AEI) with reference (BES-2017-083043).

Herein, we exploit the well-known swelling behaviour of metal–organic frameworks (MOFs) to create a selffolding polymer film. Namely, we show that incorporating crystals of the flexible MOF MIL-88A into a polyvinylidene difluoride (PVDF) matrix affords a polymer composite film that undergoes reversible shape transformations upon exposure to polar solvents and vapours. Since the self-folding properties of this film correlate directly with the swelling properties of the MIL-88A crystals, it selectively bends to certain solvents and its degree of folding can be controlled by controlling the relative humidity. Moreover, it shows a shapememory effect at relative humidity values from 60% to 90%. As proof of concept, we demonstrate that these composite films can lift cargo and can be used to assemble 3D structures from 2D patterns. Our strategy is a straightforward method for designing autonomous soft materials with folding properties that can be tuned by judicious choice of the constituent flexible MOF. Proyecto del MINECO MAT2013-41836-R y de la Junta de Andalucía P12-FQM-1656

Resumen del póster presentado al 1st Workshop Spain-Taiwan: "2D Materials and Interfaces for Spintronics", celebrado en Barcelona (España) del 23 al 25 de octubre de 2017., In topological insulators (TIs), long-range interactions between magnetic dopants mediated by the topological surface states can give rise to exotic phenomena such as the quantum anomalous Hall effect (QAHE) and dissipationless spin polarized edge currents. Such interactions, however, only occur under specific conditions of magnetic moment, anisotropy, and exchange coupling with the surrounding electron bath. Here we propose the use of metalorganic networks as an alternative strategy for tuning the electronic and magnetic interaction between the magnetic impurity and the substrate. The electronic and magnetic properties of TI surfaces modified by Brominated Cobalt tetraphenyl-porphyrin (4Br-CoTPP) networks are studied by combining Angle Resolved Photoemission Spectroscopy (ARPES) with X-Ray Magnetic Circular Dichroism (XMCD) measurements. ARPES measurements reveal that the topological surface state (TSS) is not quenched upon adsorption of slightly more than 1 ML 4Br-CoTPP in contrast with previous ARPES in Cobalt phthalocyanine/TI interfaces. The weaker interaction between the molecular layer and the substrate is confirmed by XMCD measurements where a strong in-plane magnetic moment is preserved. This ligand-mediated tuneability of interfacial interactions, together with the well-known capability of controlling magnetic anisotropy, makes the use of metalorganic molecules a promising route for engineering the electronic and magnetic properties of hybrid TI-based heterostructures.

Resumen del póster presentado a la 10th Conferencia Fuerzas y Túnel, celebrada en Girona (España) del 5 al 7 de septiembre de 2016., Designing functional devices based on organic films require a detailed knowledge of the mechanisms that govern their electronic properties. Therefore, it is of prime importance to understand the close relationship existing between the molecular organization of an organic film and its electronic structure. Additionally, the doping of organic semiconductors by using electron donor species like alkali atoms constitutes an effective strategy to improve the performance of organic optoelectronic devices and fabricating materials with exotic electronic properties, such as organic superconductors. Here, we investigate the influence of chemical doping and molecular organization on the electronic properties of a metal-porphyrin derivative (CoTPPBr) by using low-temperature scanning tunneling microscopy (LT-STM) and spectroscopy (STS) techniques. During this work, we observed that the CoTPPBr molecule forms a square self-assembled structure on the Au(111) substrate, similar to what it is generally observed for metalloporphyrin derivatives. In contrast, new self-assembled networks based on the CoTPPBr molecule were seen on the Ag(111) substrate. Additionally, a covalently bound architecture was formed on both substrates after a thermally activated de-bromination reaction. As a consequence, a shift of the HOMO and LUMO orbitals toward higher energies is observed on the silver substrate but not on the gold. Furthermore, a strong modification of the electronic properties of the metal-organic film upon chemical doping was observed using alkali atoms. After doping, the d-levels suffer a drastic change and according to the STS spectra near the Fermi level this has strong consequences to the magnetic state of the molecule. The results presented here give some insights in the realization of covalent metalorganic networks with desired electronic properties.

Fecha de solicitud: 05-11-2009.- Titular: Consejo Superior de Investigaciones Científicas (CSIC), The present invention describes a metallo-organic system that includes: a metal ion salt or complex; at least one organic ligand; and a substance of interest to be encapsulated, belonging to the group comprising a biological entity, a drug, a vaccine, a diagnostic contrast agent, a marker, an organic compound, an inorganic compound, a metallo-organic compound or a nanomaterial or nanodevices. Also described is the method for obtaining same and the uses thereof for the release and/or protection and/or storage of said substances in the pharmaceutical, chemical, environmental, medical and industrial sectors., La presente invención describe un sistema metallo-organic que incluya: una sal del ion metálico o complejo por lo menos un ligand orgánico y una sustancia del interés de ser encapsulado, perteneciendo al grupo comprendiendo una entidad biológica, un fármaco, una vacuna, un agente de contraste del diagnóstico, un marcador, un compuesto orgánico, un compuesto inorgánico, un compuesto metallo-organic o un nanomaterial o nanodevices. También descrito es el método para obtener mismo y los usos de eso para la liberación y/o la protección y/o almacenamiento de las sustancias dichas en el farmacéutico, el producto químico, el ambiental, médico y los sectores industriales.

Two novel Mn12 derivatives [Mn12O12(O2CC≡CH)16(H2O)4]·3H2O (1) and [Mn12O12(O2CC≡C6H5)16(H2O)4]·3H2O (2) have been prepared and characterized. Magnetic measurements confirm that both function as single-molecule magnets (SMM), showing frequency-dependent out-of-phase AC susceptibility signals and magnetization hysteresis curves. Thermal stability studies of both complexes were first conducted in the solid state. While complex 1 undergoes a sudden exothermal decomposition at Tonset = 118 °C, complex 2 exhibits a higher stability. Thermolysis reaction of 1 was hence assessed in solution to yield dark red crystals of a two-dimensional MnII-based co-ordination polymer [Mn3(O2CC≡CH)6(H2O)4]·2H2O (3), which corresponds to an extended sheet-like structure that crystallizes in the monoclinic space group P2 1/n; a = 9.2800(2) Å, b = 9.4132(2) Å, c = 14.9675(3) Å, β = 99.630(1)°, and Z = 2. Finally, the magnetic properties of complex 3 have been studied on an oriented single crystal over two different orientations of the reciprocal vector versus the external field., This work was supported by the Spanish government under MAT 2002–0043, the Generalitat de Catalunya under XI2002-9, the Gobierno de Aragon under the project Nanomateria and the EU under the NoE Magmanet. P. G. is grateful to the Region Languedoc-Roussillon for its financial support through the Communeaute de Travail des Pyrénées network DeNaMol. D. R.-M. also wants to thank Prof. David Hendrickson for fruitful discussions on the chemistry of Mn12 clusters and the Institut Catala de Nanotecnologia for financial support.

Here, we report the synthesis of (multi)-layered zeolitic imidazolate framework (ZIF-8/-67) composite particles via a sequential deconstruction–reconstruction process. We show that this process can be applied to construct ZIF-8-on-ZIF-67 composite particles whose cores are the initially etched particles. In addition, we demonstrate that introduction of functional inorganic nanoparticles (INPs) onto the crystal surface of etched particles does not disrupt ZIF particle reconstruction, opening new avenues for designing (multi)-layered ZIF-on-INP-on-ZIF composite particles comprising more than one class of inorganic nanoparticles. In these latter composites, the location of the inorganic nanoparticles inside each single metal–organic framework particle as well as of their separation at the nanoscale (20 nm) is controlled. Preliminary results show that (multi)-layered ZIF-on-INP-on-ZIF composite particles comprising a good sequence of inorganic nanoparticles can potentially catalyze cascade reactions., This work was supported by the EU FP7 ERC-Co 615954, the Spanish MINECO (projects PN MAT2015-65354-C2-1-R, MAT2015-70725-R, and CTQ2016-77989-P), and the Catalan AGAUR (projects 2014 SGR 80, 2014 SGR 612 and 2014 SGR 862). It was also funded by the CERCA Program/Generalitat de Catalunya. N.G.B. acknowledges financial support by MINECO through the Ramon y Cajal program (RYC-2012-10991). ICN2 acknowledges the support of the Spanish MINECO through the Severo Ochoa Centers of Excellence Program under Grant SEV-2013-0295.

Here, we report the covalent post-synthetic modification (CPSM) of MOFs using the photothermal effect. Specifically, we subjected mixtures of a photothermally active MOF and another reagent to irradiation with a UV-Vis lamp. This caused the MOF to heat up, which in turn caused the other reagent to melt and subsequently react with the functional groups on the walls of the MOF pores. We have exploited this dual function of MOFs as both heater and host for CPSMs to achieve rapid formation of amides from the reaction of representative MOFs (UiO-66-NH2 or MIL-101-NH2-(Al)) with anhydrides under solvent-free conditions. In addition, this approach enables more complex CPSMs in MOFs such as the formation of amides in UiO-66-NH2 by using an aldehyde through a cascade reaction., This work was supported by the EU FP7 ERC-Co 615954, the Spanish MINECO (project PN MAT2015-65354-C2-1-R), and the Catalan AGAUR (project 2014 SGR 80). It was also funded by the CERCA Programme/Generalitat de Catalunya. ICN2 acknowledges the support of the Spanish MINECO through the Severo Ochoa Centers of Excellence Programme under Grant SEV-2013-0295. J. E. acknowledges the MINECO for the FPI fellowship.

La presente tesis doctoral se ha enfocado en el diseño y la síntesis de un nuevo tipo de materiales compuestos basados en metal-organic frameworks (MOFs) o covalent-organic frameworks (COFs) y nanopartículas inorgánicas y el uso de estos materiales compuestos para la catálisis heterogénea. En el primer capítulo se introduce la familia de materiales compuestos dispersos en/sobre diferentes materiales haciendo especial énfasis en aquellos construidos con MOFs y COFs. En el capítulo 2 se presentan los objetivos generales de la tesis doctoral. En el capítulo 3 se muestran los resultados del artículo “The influence of the MOF shell thickness on the catalytic performance of composites made of inorganic (hollow) nanoparticles encapsulated into MOFs” publicado en 2016 en la revista Catalysis Science & Technology. En el mismo se reporta la encapsulación de nanopartículas huecas de Platino y Paladio en el ZIF-8 formando así una serie de materiales compuestos en los cuales el espesor de la cáscara de ZIF-8 era modulada de manera sistemática. En el capítulo 4, nanopartículas híbridas de tipo núcleo-coraza de Au/CeO2 dispersadas en microesféras de UiO-66 han sintetizados usando el método se atomización por secado con flujo continuo. Las propiedades catalíticas combinadas en una única partícula de los nanocristales de CeO2 y Au y la capacidad protectora de las microesféras porosas de UiO-66 hacen que estos materiales compuestos muestren resultados interesantes como catalizadores para la reacción de reducción de monóxido de Carbono. (T50 = 72 °C; T100 = 100 °C) con alta reusabilidad. Los resultados obtenidos han sido incluidos en el artículo. “Core-shell Au/CeO2 nanoparticles supported in UiO-66 beads exhibiting full CO conversion at 100 °C” publicado en la revista Journal of Materials Chemistry A en 2017. Finalmente, en el capítulo 5, hemos demostrado que usando un método en dos pasos se pueden funcionalizar COFs confinando en ellos nanopartículas. La reacción directa entre el 1,3,5-tris(4-aminofenil)benceno y el 1,3,5-benzenetricarbaldehído en presencia de una variedad de nanopartículas metalícas o de óxidos de metal resulta en la encapsulación de estas nanopartículas en un polímero amorfo de iminas-enlazadas con forma de esfera. El Post-tratamiento de estas esferas con ácido acético en reflujo conduce a la obtención de esferas cristalinas de COFs basados en iminas. Además materiales compuestos basados en COF y nanopartículas de Au y Pd han demostrado ser catalíticamente activas. Estos resultados han sido publicados en el artículo “Confining Functional Nanoparticles into Colloidal Imine-Based COF Spheres by a Sequential Encapsulation-Crystallization Method” publicado en la revista Chemistry a European Journal en 2017. The present PhD Thesis has been dedicated to the design and synthesis of a new type of composites of metal-organic frameworks (MOFs) or covalent-organic frameworks (COFs) with inorganic nanoparticles (iNPs) and the use of these composites for heterogeneous catalysis. In the first chapter, we introduce the family of composites made by supporting iNPs on/in different materials, focusing on those constructed with MOFs and COFs. Then, the general objectives of the Thesis are described in Chapter 2. Chapter 3 shows the results in “The influence of the MOF shell thickness on the catalytic performance of composites made of inorganic (hollow) nanoparticles encapsulated into MOFs”, Catalysis Science & Technology (2016). Herein, we report the encapsulation of hollow Pt or Pd nanoparticles (NPs) into ZIF-8, making a series of composites in which the ZIF-8 shell thickness has been systematically varied. By using these composites as catalysts for the reduction of 4-nitrophenol and Eosin Y, we show that the MOF shell thickness plays a key role in the catalytic performance of this class of composites. In Chapter 4, hybrid core-shell Au/CeO2 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. The results are included in the manuscript entitled “Core-shell Au/CeO2 nanoparticles supported in UiO-66 beads exhibiting full CO conversion at 100 °C”, Journal of Materials Chemistry A (2017). Finally, in Chapter 5, we demonstrated a two-step method that enables imparting new functionalities to COFs by nanoparticle confinement. The direct reaction between 1,3,5-tris(4-aminophenyl)benzene and 1,3,5-benzenetricarbaldehyde in the presence of a variety of metallic/metal-oxide nanoparticles resulted in the embedding of the nanoparticles in amorphous and nonporous imine-linked polymer organic spheres. Post-treatment reactions of these polymers with acetic acid under reflux led to crystalline and porous imine-based COF- hybrid spheres. Interestingly, porous imine-based COF-hybrids with Au and Pd NPs were found to be catalytically active. These results have been reported in the publication entitled “Confining Functional Nanoparticles into Colloidal Imine-Based COF Spheres by a Sequential Encapsulation-Crystallization Method”. Chemistry a European Journal (2017).

Una nueva era en la química de los materiales inició con el descubrimiento de las redes Metal-Orgánicas (MOFs, por sus siglas en inglés) y las redes Orgánicas-Covalentes (COFs, por sus siglas en inglés). En particular, la introducción de la química reticular representó una estrategia revolucionaria que proporcionó a los químicos infinitas oportunidades para diseñar y construir nuevos materiales funcionales con propiedades excepcionales, como su alta porosidad, alta flexibilidad estructural / composicional y bajas densidades (para COF). De hecho, estas propiedades convierten a los MOFs y a los COFs en materiales prometedores para múltiples aplicaciones de interés comercial, que incluyen almacenamiento y separación de gases, catálisis, administración de fármacos, baterías térmicas y sistemas de refrigeración. Estas posibilidades han promovido un ritmo de expansión rápido y explosivo en este campo y, como resultado, la academia y la industria han comenzado a proponer varias iniciativas para la comercialización de estos materiales porosos. Sin embargo, a pesar de estos esfuerzos, la comunidad científica también ha reconocido que el uso de estos materiales podría verse limitado por los desafíos relacionados con sus métodos de producción a gran escala, ya que normalmente se necesitan condiciones severas para sintetizarlos. En este sentido, nuevas estrategias para su síntesis se han desarrollado recientemente. En particular, el método de secado por pulverización ha surgido como una tecnología prometedora para la síntesis de MOF a gran escala. Sin embargo, el secado por pulverización todavía está en sus etapas iniciales y, por lo tanto, hay muchos desafíos que deben superarse. En esta tesis, hemos desarrollado nuevas estrategias para sintetizar MOFs. En particular, hemos desarrollado un nuevo método para la síntesis de MOFs basados en unidades de construcción secundarias. También, hemos demostrado que el método de secado por atomización acoplado a un sistema de flujo-continuo puede ser usado no solo para sintetizar MOFs, sino también para incorporar especies funcionales. De este modo, se introduce una nueva ruta para la síntesis de materiales compuestos. En esta tesis, se extiende el uso de la técnica de secado por pulverización a la química covalente. De esta manera, se muestra que diferentes iminas pueden ser sintetizadas a partir de reacciones de condensación entre aldehídos y aminas. Además, también demostramos que los MOFs pueden ser fácilmente modificados. De esta manera, usando la técnica de secado por pulverización, mostramos la modificación post-sintética de dos MOFs, el amino-terminal UiO-66-NH2 y el aldehído-terminal ZIF-90. Además, también se demuestra que las reacciones de condensación pueden extenderse para la síntesis de COFs. Así, demostramos que superestructuras esféricas creadas a partir del ensamblaje de nanocristales de COF pueden ser obtenidas en un proceso de dos pasos, que incluye el secado por pulverización seguido de una transformación amorfo-cristalino del material. Además, se demuestra como las superestructuras resultantes pueden ser utilizadas para encapsular diferentes materiales, tales como moléculas fluorescentes y nanopartículas magnéticas. A new age in materials chemistry started with the discovery of Metal-Organic Frameworks and Covalent-Organic frameworks. In particular, the introduction of reticular chemistry represented a revolutionary strategy that gave chemists infinite opportunities toward the design and construction of novel functional materials with exceptional properties, such as their high porosity, high structural/compositional flexibility and low densities (for COFs). Indeed, these properties render MOFs and COFs as promising materials for multiple applications of commercial interest, including gas storage and separation, catalysis, sensing, drug delivery, water harvesting and adsorptive heat transformation systems. These possibilities have promoted a rapid and explosive pace of expansion in this field and as a result, academia and industry have begun to propose several initiatives towards the commercialization of these porous materials. However, despite these efforts, the scientific community has also recognized that the use of these materials could be limited by the challenges pertaining to their production methods at large scale since harsh conditions are usually needed to synthesize them. In this sense, novel approaches for their synthesis have been developed recently. In particular, the spray-drying method has emerged as a promising technology for the synthesis of MOFs at large scale. However, spray-drying is still in its embryonic stage and therefore, there are many challenges that need to be overcome. In this Thesis, we have developed new strategies to synthesize MOFs. In particular, we describes a new methodology based on coupling two processes —spray-drying and continuous flow— for continuous synthesis of MOFs assembled from high-nuclearity secondary building units (SBUs). In addition, we demonstrated that the spray-drying-continuous flow method can be used not only to synthesize MOF superstructures but also to incorporate functional species, thereby providing a new route for the synthesis of MOF-based composites. In this thesis, we extend the use of spray-drying technique to covalent chemistry. To this end, we show that different imines can be synthesized from Schiff-base condensation reactions between discrete aldehydes and amines using the spray-drying. We also show that this chemistry can be extended to post-synthetically modify MOFs. For example, we show the post-synthetic modification of two MOFs, the amine-terminated UiO-66-NH2 and the aldehyde-terminated ZIF-90. Moreover, we demonstrate that the Schiff-base condensation reactions can be extended to the synthesis of COFs. Thus, we prove that spherical superstructures made from the assembly of imine-based COF nanocrystals can be obtained by combining the spray-drying technique with a dynamic covalent chemistry process. In addition, we show that this methodology enables the integration of other functional materials such as dyes and magnetic nanoparticles into these superstructures forming COF-based composites.

La present Tesis ha estat dedicada a la síntesis de materials Metal·lorgànics a la nanoescala (NMOFs, fent servir l’acrònim anglès) i l’estudi de les seves potencials aplicacions com a Agents de Contrast (AC) en Imatgeria per Ressonància Magnètica. En conseqüència, dos línies de treball es distingeixen al llarg de la lectura d’aquesta Tesis: (ii) el desenvolupament de una nova metodologia per a sintetitzar NMOFs, i (ii) la síntesis de nous NMOFs que puguin complir els requeriments específics per tal de ser utilitzats com a AC. En el primer capítol, revisem la evolució que ha viscut el camp dels MOFs, des de els seus antecedents que van fer possible el seu descobriment fins a les seves aplicacions actuals i les seves noves perspectives. Prestem especial atenció a les actuals metodologies emprades per a sintetitzar NMOFs, i al adveniment de noves aplicacions aparegudes gràcies a la seva mida nanoscòpica. El en Capítol 3 descrivim la validació de la tècnica coneguda com Spray-Drying (SD) com a nova metodologia per sintetitzar NMOFs i les superestructures buides que se’n deriven. S’estudia l’impacte dels principals paràmetres experimentals en la síntesi del NMOFs així com les diferents modalitats de usatge que ofereix la tècnica. Precisament, la versatilitat de la tècnica ens ha permès sintetitzar un ampli ventall de NMOFs pertanyent a les subfamílies més representatives. El Capítol 4 explica les possibilitats de utilitzar la tècnica de SD per a combinar NMOFs amb altres especies funcionals per tal de sintetitzar compòsits basats en MOFs. Demostrem com les superestructures buides de NMOFs poden ser utilitzades per a encapsular diferents materials, tals com cristalls de NaCl, molècules fluorescents i nanopartícules magnètiques. A més, també demostrem com cristalls de NMOFs poden ser fàcilment encapsulats en matrius polimèriques mitjançant la tècnica de SD. La varietat de compòsits basats en MOFs que es pot obtenir utilitzant la tècnica de SD permet ampliar el ventall d’aplicacions dels NMOFs. En el capítol 5 es descriu la segona línia de treball que conforma la present Tesis doctoral referent a la síntesis de una nova generació de NMOFs amb propietats de AC. La estratègia consisteix en utilitzar lligands heterocíclics emprats en la síntesis dels AC moleculars, els quals presenten una gran afinitat per als ions de Gd(III). El lligand heterocíclic DOTP s’utilitza per l’assemblatge de un MOF bimetàl·lic i porós. Aquest MOF és miniaturitzat a la nanoescala per a forma dispersions col·loïdals estables; és estable en medi fisiològic, en cultiu cel·lular i no presenta citotoxicitat. A més, presenta unes propietats de AC interessants, com ho demostra la relaxativitat mesurada a camp magnètic alt (r1 = 5 mM-1·s-1 a 500 MHz) i una relaxativitat màxima a 40 MHz de 15 mM-1·s-1, la qual es manté constant al llarg de un ampli ventall de pH., The present Thesis has been dedicated to the synthesis of nanoscale Metal-Organic Frameworks (NMOFs) and the study of their potential application as Contrast Agents (CAs). Accordingly, two main lines of work can be distinguished through the lecture of this Thesis: i) the development of a novel synthetic methodology to synthesise NMOFs; and ii) the synthesis of new NMOFs that meet the specific requirements for their use as CAs. In the first Chapter, we review the evolution of the field of MOFs, from their antecedents that made their discovery possible to their current applications and prospects. We pay special attention to the current methodologies to synthesise MOFs at the nanoscale, and the advent of new applications resulting from their small size. Chapter 3 describes the validation of the Spray-Drying (SD) technique as a new methodology to synthesise NMOFs and their related hollow superstructures. The impact of the main experimental parameters on the synthesis of NMOFs is given as well as the different modes of operations that the SD technique offers for their synthesis. The versatility of the technique has allowed us to synthesise a wide panel of NMOFs belonging to the most representative subfamilies. In Chapter 4 the possibilities of combining NMOFs with other functional species using the SD technique to synthesise MOF-based composites is explained. We show how the MOF-based hollow superstructures can be used to encapsulate different materials, including NaCl crystals, dyes and FeOx inorganic nanoparticles (INPs). Furthermore, we also prove that NMOFs can also be easily encapsulated within functional matrices, such as polymers, by SD. Finally, we demonstrate that the unique capabilities of the SD to create MOF-based composites can be exploited to further expand the applications of NMOFs. In the second axis of this Thesis, Chapter 5 describes the synthesis of a new generation of NMOFs with CA properties. The strategy consists on using heterocyclic ligands currently employed in the synthesis of molecular CAs, which possess high chelating capabilities towards Gd(III) ions. The macrocyclic ligand DOTP is used to assemble a porous, heterometallic MOF. This MOF is miniaturizable down to the nanoscale to form stable colloids; is stable in physiological saline solution and cell culture media; and is not cytotoxic. It shows interesting relaxometric properties with a r1 at high field (500 MHz) of 5 mM-1·s-1 and a maximum in r1 of 15 mM-1·s-1 at 40 MHz, which remains constant over a wide pH range and increases with temperature.

La present Tesi Doctoral s'ha dedicat a explorar les capacitats de coordinació d’aminoàcids i pèptids per tal de desenvolupar nous Polimers de Coordinació (PCs) en forma de nanofibres a escala nanoemetrica, i poder utilitzar-los com a (doble) plantilla per la síntesi de superestructures fetes amb nanopartícules inorgàniques (INPs). Utilitzar PC en forma de nanofibres com a doble plantilla té l’avantatge de poder aprofitar tant les propietats de plantilla com les característiques inherents de reconeixement dels pèptids per tal de formar CPs. En el primer capítol es mostra una breu introducció als PC, centrant-se en l’ús de biomolècules. Aquest capítol inclou el treball titulat "Metal–biomolecule frameworks (MBioFs)", Chem. Commun (2011), on es fa una estesa i detallada descripció sobre aquests tipus de materials. A continuació, els objectius generals d'aquesta tesi es descriuen en el capítol 2. El Capítol 3 resumeix els resultats reportats en "Amino acid-based metal-organic nanofibers", J. Am. Chem. Soc. (2009). Aquí, es mostra la síntesi i caracterització de nanofibres de CP i gels construïts a partir de la coordinació d'amino àcids (L-o àcid D-aspàrtic, Asp) i ions metàl · lics (Cu (II) ions). Les nanofibres quirals de Cu(II)-Asp resultants s’han sintetitzat utilitzant tècniques de precipitació ràpida i de difusió lenta, amb les quals la longitud d’aquestes pot arribar fins a 1 centímetre. En el capítol 4, les nanofibres de Cu(II)-Asp s'han utilitzat com a cas-escenari de prova per explorar la tècnica de microfluídica (més precisament flux laminar) com a nou mètode sintètic per tal d'aconseguir un control més precís sobre l’assamblatge d'ions metàl·lics amb AA. S’ha demostrat que, a diferència dels procediments sintètics comuns, aquesta aproximació permet la síntesi en paral·lel amb un eminent nivell sobre el control de la coordinació, facilitant la formació de 1-D PC ensamblats a escala nanomètrica. A més de les nanofibres de Cu(II)-Asp, l’ús de la microfluidica ha permès la síntesis d’un segon tipus de nanofibres fetes amb aminoàcids, Ag(I)-Cisteina (Cys). S’ha confirmat que aquestes nanoestructures no es poden obtenir amb mètodes tradicionals com el de la precipitació ràpida dels dos components. Aquests resultats s'inclouen en el manuscrit "Coordination polymer nanofibers generated by microfluidic synthesis", J. Am. Chem. Soc. (2011). En un següent pas, el capítol 5 es centra en l'ús de les nanofibres de Ag (I)-Cys com a plantilles per tal de sintetitzar i acoblar NP inorgàniques en superestructures 1-D. En aquest capítol, primer es motra la síntesi de NPs de Ag2S ensamblades en 1-D exposant les nanofibres de Ag(I)-Cys sota un bombardeig d'electrons. A continuació, es mostra que aquestes plantilles sintetitzadades poden localitzar-se en posicions precises mitjançant la tecnologia de la microfluidica amb la incorporació de vàlvules de fluids microfabricades incorporades. La microfluídica permet orientar i localitzar la formació de les nanofibres de Ag (I)-Cys i a més, l'ús de vàlvules permet la immobilització de les fibres i poder utilitzar-les com a plantilles per a la síntesis de 1-D superestructures de NPs deAg. Aquestes superestructures s'han sintetitzat mitjançant la reducció (àcid ascòrbic) dels ions de Ag(I) que es troben dins de la plantilla. El nivell de control assolit amb la microfluídica ha permès que es puguin utilitzar més a fons aquestes superestructures de Ag NP com a segones plantilles per sintetitzar cristalls conductors de Ag (I)-tetracyanoquinodinmethane (TCNQ), permetent a més la mesura directe de les seves propietats de conductivitat. Tots aquests resultats estan inclosos en l'article presentat en el capítol 4 i en l'article titulat "Localized template growth of functional nanofibers from an metal-amino acid-supported framework in a microfluidic chip", ACS Nano 2014. Finalment, en el capítol 6, s'ha incrementat la complexitat dels PCs de Ag(I) fets a partir d'aminoàcids amb pèptids per tal d’explotar les característiques inherents de reconeixement que tenen els pèptids. S'ha sintetitzat una nova classe de plantilles metall-pèptid, cristalls de Ag(I)-DLL similars a cintes, amb els quals s'ha demostrat que poden ser utilitzats com a doble plantilla per a la síntesi i assamblatge de dos tipus de NPs inorgàniques, unes sobre la seva superfície (cara del cristall) i les altres dins de les seves estructures internes. En aquestes plantilles, les capacitats d'auto-assamblatge i reconeixement dels pèptids, i la reducció selectiva dels ions Ag(I) a Ag s'han explotat simultàniament per tal de controlar el creixement i l'assamblatge de més complexos multicomposicionals de superestructures amb NP inorgàniques. S'ha demostrat que aquests cinturons Ag(I)-DLL poden ser utilitzats com a dobles plantilles per crear llargues (> 100 µm) i polimetàl·liques superestructures conductores de Ag@AgNP i compostos multifuncionals de NPs de Fe3O4@Ag combinant les propietats magnètiques i conductores dels dos tipus de NPs. Aquests resultats han estat reportats en el manuscrit titulat "“Dual-template” Synthesis of one-dimensional conductive NP superstructures from coordination metal-peptide polymer crystals", Small (2013)., The present PhD Thesis has been dedicated to explore the coordination capabilities of amino acids and peptides to create novel nanoscale Coordination Polymers (CPs) in the form of nanofibers, and to use these nanofibers as (dual) scaffolds for the synthesis of superstructures made of inorganic nanoparticles (INPs). The use of CP nanofibers as dual scaffolds has taken advantage of the templating characteristics of CPs as well as the inherent recognition-template characteristics of the peptide that has been used to form the CP. In the first Chapter, we show a brief introduction to CPs, focusing on those constructed from biomolecules. This Chapter includes the review entitled "Metal–biomolecule frameworks (MBioFs)", Chem. Commun (2011), in which an extended, detailed description of this type of materials was reported. Then, the general objectives of this Thesis are described in Chapter 2. Chapter 3 summarizes the results reported in "Amino acid-based metal-organic nanofibers", J. Am. Chem. Soc.(2009). Here, we show the synthesis and characterization of CP nanofibers and gels built up from the coordination of amino acids (L- or D-aspartic acid, Asp) and metal ions (Cu(II) ions). The resulting chiral Cu(II)-Asp nanofibers have been synthesized using fast precipitation and slow diffusion techniques, from which their lenght could be extended up to 1 centimeter. In Chapter 4, Cu(II)-Asp nanofibers have been used as the test-case-scenario to explore microfluidics technology (more precisely, laminar flow) as a new synthetic approach to achieve precise control over the assembly of metal ions and amino acids. We have demonstrated that unlike common synthetic procedures, this approach enables parallel synthesis with an unprecedented level of control over the coordination pathway and facilitates the formation of 1D CP assemblies at the nanometer length scale. In addition to Cu(II)-Asp nanofibers, the use of microfluidics has allowed the synthesis of a second type of CP nanofibers made of amino acids Ag(I)-Cysteine (Cys) nanofibers. We have also confirmed that these nanostructures can not be synthesized with more traditional methods, such as fast mixing of both components. All these results are included in the manuscript entitled "Coordination polymer nanofibers generated by microfluidic synthesis", J. Am. Chem. Soc. (2011). In a next step, Chapter 5 focuses on the use of the Ag(I)-Cys nanofibers as templates to synthesize and assemble inorganic NPs into 1D superstructures. In this Chapter, we first show the synthesis of 1-D assemblies of Ag2S NPs by exposing the Ag(I)-Cys nanofibers to e-beam bombardment. We then show that this template synthesis can be localized at precise positions by using microfluidic technology with micro-engineered fluidic clamps incorporated. Microfluidics allows guiding and localizing the formation of Ag(I)-Cys nanofibers, whereas the use of clamps allows immobilizing these fibers and use them as templates to synthesize 1-D Ag NP superstructures. These superstructures have been synthesized via reduction (ascorbic acid) of the Ag(I) ions inside the scaffold structure. We anticipate that the level of control achieved with microfluidics has allowed us to further use these Ag NP superstructures as second templates to synthesize conductive Ag(I)-tetracyanoquinodinmethane (TCNQ) CP crystals, allowing also the direct measurement of their conductivity properties. All these results are included in the article presented in Chapter 4 and in the article entitled "Localized template growth of functional nanofibers from an metal-amino acid-supported framework in a microfluidic chip", ACS Nano 2014. Finally, in Chapter 6, we have increased the complexity of the Ag(I)-based CP from amino acids to peptides to exploit the inherent recognition-template characteristics of peptides. Here, we have synthesized a new class of metal-peptide scaffolds, Ag(I)-DLL belt-like crystals, that were proved to be used as dual-templates for the synthesis and assembly of two types of inorganic NPs, one on their surface (crystal face) and the other within their internal structures. In these CP scaffolds, the self-assembly and recognition capacities of peptides and the selective reduction of Ag(I) ions to Ag are simultaneously exploited to control the growth and assembly of more complex, multicompositional inorganic NP superstructures. We demonstrate that these Ag(I)-DLL belts could be applied as dual templates to create long (> 100 μm) conductive Ag@Ag NP superstructures and polymetallic, multifunctional Fe3O4@Ag NP composites that marry the magnetic and conductive properties of the two NP types. These results have been reported in the manuscript entitled "“Dual-template” Synthesis of one-dimensional conductive NP superstructures from coordination metal-peptide polymer crystals", Small (2013).

La presente Tesis Doctoral se ha dedicado al estudio, desarrollo e implementación de métodos para la síntesis y micro- nanoestructuración de materiales metal-orgánicos porosos (MOFs, Metal-Organic Frameworks) sobre superficies. La importancia en la estructuración de MOFs con alta resolución radica en la necesidad de su integración en microdispositivos, especialmente de tipo sensor. En el primer capítulo se realiza una prospección bibliográfica sobre el estado del arte en MOFs, con una breve introducción histórica, las principales rutas sintéticas, propiedades y aplicaciones. Se introducen también los nano-MOFs (NMOFs) con sus particularidades tanto sintéticas como relativas a sus propiedades y aplicaciones. Este capítulo incluye el trabajo de revisión titulado “Nanoscale Metal-Organic Materials”, Chemical Society Reviews (2010) donde se da una descripción extensa y más genérica sobre materiales Metal-Orgánicos. El Capítulo 2 cita los objetivos generales y particulares de la presente Tesis Doctoral. En el Capítulo 3 se introduce la nanoestructuración de MOFs en superficie y se desarrolla un nuevo método para nanoestructurar un MOF en particular (HKUST-1) sobre superficies con precisión nanométrica y al nivel de monocristales. Además de desarrollar un nuevo y versátil método para nanoestructurar HKUST-1 en superficies, se estudia cómo influye la funcionalización de la superficie sobre el crecimiento, nucleación y orientación cristalina. Los resultados de este capítulo se incluyen en el artículo “Single-Crystal Metal-Organic Framework Arrays”, Journal of the American Chemical Society, (2011). A partir del análisis de los resultados y problemáticas aparecidas en el capítulo anterior, en el Capítulo 4 se desarrolla una nueva aproximación que permite ampliar el abanico de MOFs viables para su estructuración. Así, en este capítulo se estudian las características de la nueva aproximación basada en combinar reactivos en volúmenes del orden de los femtolitros (10-15 l) utilizando una sonda de nanolitografía por microfluídica. Se demuestra la habilidad para realizar diferentes reacciones químicas y bioquímicas confinadas en dicho rango de volúmenes. Más adelante se demuestra la utilidad de la nueva aproximación para estructurar MOFs diferentes en un espacio micrométrico de una superficie realizando química combinatoria. Finalmente, se demuestra que dicha aproximación se puede utilizar para la detección combinatoria de posibles nuevos materiales, en nuestro caso se descubren dos nuevos bioMOFs. Los resultados de este trabajo se incluyen en el artículo “Femtolitre Chemistry assisted by microfluidic pen lithography” Nature Communications, (2013)., The present PhD Thesis has been dedicated to the study, development and implementation of methods for the synthesis and nanostructuring of Metal-Organic Frameworks (MOFs) on surfaces. The importance in structuring MOFs with high resolution is the need for their integration into microdevices, especially sensors. In the first chapter a literature survey on the state of the art in MOFs, with a brief historical introduction, the main synthetic routes, properties and applications is given. Nano-MOFs (NMOFs) are also introduced with both synthetic and properties and application characteristics. This chapter includes the review paper entitled "Nanoscale Metal-Organic Materials", Chemical Society Reviews (2010) where an extensive and more generic description of Metal-Organic material is developed. Chapter 2 cites the general and specific objectives of this PhD thesis. In Chapter 3 nanostructuring of MOFs on surfaces is introduced and a new method to nanostructure a particular MOF (HKUST-1) on surfaces with nanometer precision even at the level of single crystals is developed. In addition to developing a new and versatile method for HKUST-1 surface nanoestructure, we study how the surface functionalization influences on the growth, nucleation and crystal orientation. The results of this chapter are included in the article "Single-Crystal Metal-Organic Framework Arrays", Journal of the American Chemical Society, (2011). From the analysis of the results and issues that appeared in the previous chapter, in Chapter 4 is developed a new approach that can extend the range of viable MOFs for structuring. Thus, in this chapter the characteristics of the new approach based on combining reagents in volumes on the order of femtoliters (10-15 l) using a nanolithography microfluidic probe is studied. It is demonstrated the ability to perform various confined chemical and biochemical reactions in this volume range. Also, the utility of the new approach to structure different MOFs in a space of a micrometer performing combinatorial chemistry surface is demonstrated. Finally, it is shown that this approach can be used for combinatorial detection of possible new materials, in our case two new bioMOFs are discovered. The results of this work are included in the article "Femtolitre Chemistry assisted by microfluidic pen lithography" Nature Communications, (2013).