37 research outputs found

    Sonochemical synthesis of a novel nanoscale 1D lead(II) [Pb2(L)2(I)4]n coordination Polymer, survey of temperature, reaction time parameters

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    One new lead(II) coordination supramolecular complex (CSC) (1D), [Pb(L)(I)], L = CHN (1-methyl imidazole), has been synthesized under different experimental conditions. Micrometric crystals (bulk) or nano-sized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on complex 1 showed that Pb ion is 4-coordinated. Topological analysis shows that the complex 1 is 2,3,5C2 net. Finally, the role of reaction time and temperature on the growth and final morphology of the structures obtained by sonochemical irradiation have been studied

    Sonochemical synthesis of two novel Pb(II) 2D metal coordination polymer complexes : new precursor for facile fabrication of lead(II) oxide/bromide micro-nanostructures

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    Two new lead(II) coordination polymer complexes (CSCs) (2D), [Pb(L)(Br)]·HO (1), [Pb(HL)(L)(HO)]·HO (2), where L = CHNO (2-pyridinecarboxylic acid) and L = CHO (1,3,5-tricarboxylic acid), have been synthesized under different experimental conditions. Micrometric crystals (bulk) or microsized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on complexes 1 and 2 shows that Pb ions are 8-coordinated, 7 and 9-coordinated, respectively. Topological analysis shows that the compound 1 and 2 are 4,6L26 and bnn net, respectively. However, neither the shape nor the morphology is maintained, showing the role of sonochemistry to modulate both morphology and dimensions of the resulting crystalline material, independently of whether we have a 2D coordination polymer (CP). Finally, micro structuration of lead(II) bromide oxide and lead(II) oxide have been prepared by calcination of two different lead (II) CPs at 700 °C that were characterized by SEM and XRD

    Copolymerization of a catechol and a diamine as a versatile polydopamine-like platform for surface functionalization : the case of a hydrophobic coating

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    The covalent functionalization of surfaces with molecules capable of providing new properties to the treated substrate, such as hydrophobicity or bioactivity, has been attracting a lot of interest in the last decades. For achieving this goal, the generation of a universally functionalizable primer coating in one-pot reaction and under relatively mild conditions is especially attractive due to its potential versatility and ease of application. The aim of the present work is to obtain such a functionalizable coating by a cross-linking reaction between pyrocatechol and hexamethylenediamine (HDMA) under oxidizing conditions. For demonstrating the efficacy of this approach, different substrates (glass, gold, silicon, and fabric) have been coated and later functionalized with two different alkylated species (1-hexadecanamine and stearoyl chloride). The success of their attachment has been demonstrated by evaluating the hydrophobicity conferred to the surface by contact angle measurements. Interestingly, these results, together with its chemical characterization by means of X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FT-IR), have proven that the reactivity of the primer coating towards the functionalizing agent can be tuned in function of its generation time

    Antitumour activity of coordination polymer nanoparticles

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    Altres ajuts: the ICN2 is funded by the CERCA programme / Generalitat de Catalunya.Nanoscale coordination polymers (NCPs) have fascinated researchers over the last years. Their intrinsic theranostic properties of metal ions and organic ligands, the encapsulation of several drugs/biomolecules with excellent yields and the surface functionalisation, enhancing their biocompatibility and targeting, have remarkably impacted in prospective drug delivery alternatives in medicine. Moreover, the properties and characteristics of these nanoparticles (NPs) can be fine-tuned thanks to the synthetic flexibility of coordination chemistry. For all these reasons, the number of examples published has grown exponentially over the last years, embracing different disciplines such as molecular electronics, sensors or nanomedicine, among others. Specifically, significant advances in antitumoural applications are reported, one of the areas where this novel family of NPs has experienced a considerable advance. NCPs have accomplished a high sophistication degree and efficiency as theranostic nanoplatforms (i.e., drug delivery carriers and bioimaging probes) with long residence time in the bloodstream, targeting capacities and remarkable cellular internalisation. In this review, an introduction emphasizing the advantages of NPs for cancer treatment is included. Later on, the most representative examples of NCPs for antitumoural applications are described grouped into six mean representative areas: i) encapsulation approaches, ii) stimuli-responsive NCPs, iii) metal chemotherapy, iv) photodynamic therapy (PDT), v) unconventional therapeutic approaches and vi) theranostics. Particular emphasis is given to understand the encapsulation/release properties of these particles at the nanoscale and their interaction with biological environments, highlighting any limitation and challenges that these systems are facing from a clinical translation perspective and envisioning possible future trends and areas that will deserve further attention for the following years

    Solvent-tuned ultrasonic synthesis of 2D coordination polymer nanostructures and flakes

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    Altres ajuts: the ICN2 is funded by the CERCA programme / Generalitat de Catalunya. Noemí Contreras Pereda's project that gave rise to these results received the support of a fellowship from "laCaixa" Foundation (ID 100010434). The fellowship code is LCF/BQ/ES17/11600012.Herein, a new 2-dimensional coordination polymer based on copper (II), {Cu₂(L)(DMF₂)}n, where L stands for 1,2,4,5-benzenetetracarboxylate (complex 1) is synthesized. Interestingly, we demonstrate that both solvent and sonication are relevant in the top-down fabrication of nanostructures. Water molecules are intercalated in suspended crystals of complex 1 modifying not only the coordination sphere of Cu(II) ions but also the final chemical formula and crystalline structure obtaining {[Cu(L)(H₂O)₃]·H₂O}n (complex 2). On the other hand, ultrasound is required to induce the nanostructuration. Remarkably, different morphologies are obtained using different solvents and interconversion from one morphology to another seems to occur upon solvent exchange. Both complexes 1 and 2, as well as the corresponding nanostructures, have been fully characterized by different means such as infrared spectroscopy, x-ray diffraction and microscopy

    Sonochemical synthesis, characterization, and effects of temperature, power ultrasound and reaction time on the morphological properties of two new nanostructured mercury(II) coordination supramolecule compounds

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    Two new mercury(II) coordination supramolecular compounds (CSCs) (1D and 0D), [Hg(L)(I)] (1) and [Hg(L')(SCN)]·2HO (2) (L = 2-amino-4-methylpyridine and L' = 2,6-pyridinedicarboxlic acid), have been synthesized under different experimental conditions. Micrometric crystals (bulk) or nano-sized materials have been obtained depending on using the branch tube method or sonochemical irradiation. All materials have been characterized by field emission scanning electron microscope (FESEM), scanning electron microscopy (SEM), powder X-ray diffraction (PXRD) and FT-IR spectroscopy. Single crystal X-ray analyses on compounds 1 and 2 show that Hg ions are 4-coordinated and 5-coordinated, respectively. Topological analysis shows that the compound 1 and 2 have 2C1, sql net. The thermal stability of compounds 1 and 2 in bulk and nano-size has been studied by thermal gravimetric (TG), differential thermal analyses (DTA) for 1 and differential scanning calorimetry (DSC) for 2, respectively. Also, by changing counter ions were obtained various structures 1 and 2 (1D and 0D, respectively). The role of different parameters like power of ultrasound irradiation, reaction time and temperature on the growth and morphology of the nano-structures are studied. Results suggest that increasing power ultrasound irradiation and temperature together with reducing reaction time and concentration of initial reagents leads to a decrease in particle size

    Pathway selection as a tool for crystal defect engineering: A case study with a functional coordination polymer

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    New synthetic routes capable of achieving defect engineering of functional crystals through well- controlled pathway selection will spark new breakthroughs and advances towards unprecedented and unique functional materials and devices. In nature, the interplay of chemical reactions with the diffusion of reagents in space and time is already used to favor such pathway selection and trigger the formation of materials with bespoke properties and functions, even when the material composition is preserved. Following this approach, herein we show that a controlled interplay of a coordination reaction with mass transport (i.e. the diffusion of reagents) is essential to favor the generation of charge imbalance defects (i.e. protonation defects) in a final crystal structure (thermodynamic product). We show that this syn- thetic pathway is achieved with the isolation of a kinetic product (i.e. a metastable state), which can be only accomplished when a controlled interplay of the reaction with mass transport is satisfied. Account- ing for the relevance of controlling, tuning and understanding structure-properties correlations, we have studied the spin transition evolution of a well-defined spin-crossover complex as a model system

    Colloidal coordination polymer nanostructures: novel thermochromic and bioimaging probes

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    Los polímeros de coordinación y su diseño racional permiten la formación de materiales nanoestructurados con una amplia variedad de propiedades. Las múltiples combinaciones entre iones metálicos y ligandos orgánicos como precursores de materiales autoensamblados, han fascinado a los científicos durante décadas. La aplicación de la química de coordinación a nanoescala se considera uno de los enfoques más versátiles para el desarrollo de nuevos materiales nanoestructurados debido a las infinitas posibilidades para alcanzar propiedades sin precedentes. Además, el desarrollo de sistemas metal-orgánicos ha despertado en una gran cantidad de ejemplos para su uso en una amplia gama de aplicaciones. En esta Tesis hemos estado particularmente interesados ​​en el ajuste controlado de las propiedades de los materiales nanoestructurados basados ​​en polímeros de coordinación que se obtuvieron a través de diferentes rutas sintéticas. El método de síntesis, la selección adecuada de precursores y el estudio de las propiedades finales han centrado el trabajo realizado. Además, la formación de suspensiones coloidales estables en agua se estableció como un requisito principal para su potencial aplicación. Para eso, fue necesaria una sinergia multidisciplinaria con el objetivo de buscar la aplicación final de los nuevos materiales nanoestructurados desarrollados. El logro de este objetivo fue posible gracias a un diseño adecuado de la estrategia seguida junto con la caracterización completa de las nanoestructuras preparadas. En una primera parte de esta Tesis, la nanoestructuración de sistemas conmutables basados ​​en Fe(II) con comportamiento de entrecruzamiento de espín (SCO por sus siglas en inglés) se logró siguiendo dos estrategias diferentes. Por un lado, se aplicó una metodología descendente (top-down) basada en la exfoliación en fase líquida para el aislamiento de láminas 2D de cristales multilaminares. Por otro lado, a través de un enfoque ascendente (bottom-up), la síntesis de nuevas nanopartículas fue posible modulando la difusión de la reacción utilizando metodologías basadas en microfluidica. En ambos casos, los materiales nanoestructurados se integraron en matrices poliméricas para evaluar su aplicación potencial como películas termocrómicas para su prueba de concepto. En la segunda parte de la Tesis, se estableció una nueva familia de polímeros de coordinación a nanoescala (NCP por sus siglas en inglés) basados ​​en Fe(III), Gd(III), Mn(II), In(III) y Cu(II) a través de su síntesis racional usando una reacción en un sola etapa. Las nanopartículas obtenidas se validaron mediante pruebas preclínicas in vivo que muestran un rendimiento interesante como posibles agentes teranósticos para la obtención de imágenes (resonancia magnética, tomografía por emisión de positrones y tomografía computarizada por emisión de fotón único) y pretratamiento potencial de glioblastoma y enfermedades pulmonares.Coordination polymers and its rational design let the formation of nanostructured materials with a broad variety of properties. The multiple combinations between metal ions and organic ligands as precursors of self-assembled materials have fascinated scientists for decades. The application of coordination chemistry at the nanoscale is considered one of the most versatile approaches for the development of new nanostructured materials due to the infinite possibilities for reaching unprecedented properties. Furthermore, the development of metal-organic systems has aroused in a plethora of examples for their use in a wide range of applications. In this Thesis we have been particularly interested in the fine tune of the properties of nanostructured materials based on coordination polymers whose were obtained through different synthetic routes. The method of synthesis, the properly selection of precursors and the study of the final properties has centred the work carried out. Additionally, the formation of water-stable colloidal suspensions was stablished as a main requirement for their potential application. For that, a multidisciplinary synergy was necessary with the aim to pursue the final application of the novel nanostructured materials developed. Achieving this objective was possible thanks to a properly design of the strategy followed together with complete characterization of the nanostructures prepared. In a first part of this Thesis, the nanostructuration of Fe(II)-based switchable systems with spin crossover behaviour was achieved by following two different strategies. On the one hand, a top-down methodology based on liquid-phase exfoliation was applied for the isolation of 2D flakes from the bulk crystal. On the other hand, through a bottom-up approach, the synthesis of novel nanoparticles was possible by modulating the reaction diffusion using microfluidic based methodologies. In both cases, the nanostructured materials were integrated in polymeric matrices to evaluate their potential application as proof-of-concept thermochromic films. In the second part of the Thesis, a novel family of nanoscale coordination polymers (NCPs) based on Fe(III), Gd(III), Mn(II), In(III) and Cu(II) was stablished through its rational synthesis by using one-pot reaction. The nanoparticles obtained were validated by pre-clinical in vivo tests showing interesting performance as potential theranostic agents for imaging (Magnetic resonance imaging, positron emission tomography and single-photon emission computed tomography) and potential pre-treatment of glioblastoma and lung diseases

    Colloidal coordination polymer nanostructures : novel thermochromic and bioimaging probes

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    Los polímeros de coordinación y su diseño racional permiten la formación de materiales nanoestructurados con una amplia variedad de propiedades. Las múltiples combinaciones entre iones metálicos y ligandos orgánicos como precursores de materiales autoensamblados, han fascinado a los científicos durante décadas. La aplicación de la química de coordinación a nanoescala se considera uno de los enfoques más versátiles para el desarrollo de nuevos materiales nanoestructurados debido a las infinitas posibilidades para alcanzar propiedades sin precedentes. Además, el desarrollo de sistemas metal-orgánicos ha despertado en una gran cantidad de ejemplos para su uso en una amplia gama de aplicaciones. En esta Tesis hemos estado particularmente interesados ​​en el ajuste controlado de las propiedades de los materiales nanoestructurados basados ​​en polímeros de coordinación que se obtuvieron a través de diferentes rutas sintéticas. El método de síntesis, la selección adecuada de precursores y el estudio de las propiedades finales han centrado el trabajo realizado. Además, la formación de suspensiones coloidales estables en agua se estableció como un requisito principal para su potencial aplicación. Para eso, fue necesaria una sinergia multidisciplinaria con el objetivo de buscar la aplicación final de los nuevos materiales nanoestructurados desarrollados. El logro de este objetivo fue posible gracias a un diseño adecuado de la estrategia seguida junto con la caracterización completa de las nanoestructuras preparadas. En una primera parte de esta Tesis, la nanoestructuración de sistemas conmutables basados ​​en Fe(II) con comportamiento de entrecruzamiento de espín (SCO por sus siglas en inglés) se logró siguiendo dos estrategias diferentes. Por un lado, se aplicó una metodología descendente (top-down) basada en la exfoliación en fase líquida para el aislamiento de láminas 2D de cristales multilaminares. Por otro lado, a través de un enfoque ascendente (bottom-up), la síntesis de nuevas nanopartículas fue posible modulando la difusión de la reacción utilizando metodologías basadas en microfluidica. En ambos casos, los materiales nanoestructurados se integraron en matrices poliméricas para evaluar su aplicación potencial como películas termocrómicas para su prueba de concepto. En la segunda parte de la Tesis, se estableció una nueva familia de polímeros de coordinación a nanoescala (NCP por sus siglas en inglés) basados ​​en Fe(III), Gd(III), Mn(II), In(III) y Cu(II) a través de su síntesis racional usando una reacción en un sola etapa. Las nanopartículas obtenidas se validaron mediante pruebas preclínicas in vivo que muestran un rendimiento interesante como posibles agentes teranósticos para la obtención de imágenes (resonancia magnética, tomografía por emisión de positrones y tomografía computarizada por emisión de fotón único) y pretratamiento potencial de glioblastoma y enfermedades pulmonares.Coordination polymers and its rational design let the formation of nanostructured materials with a broad variety of properties. The multiple combinations between metal ions and organic ligands as precursors of self-assembled materials have fascinated scientists for decades. The application of coordination chemistry at the nanoscale is considered one of the most versatile approaches for the development of new nanostructured materials due to the infinite possibilities for reaching unprecedented properties. Furthermore, the development of metal-organic systems has aroused in a plethora of examples for their use in a wide range of applications. In this Thesis we have been particularly interested in the fine tune of the properties of nanostructured materials based on coordination polymers whose were obtained through different synthetic routes. The method of synthesis, the properly selection of precursors and the study of the final properties has centred the work carried out. Additionally, the formation of water-stable colloidal suspensions was stablished as a main requirement for their potential application. For that, a multidisciplinary synergy was necessary with the aim to pursue the final application of the novel nanostructured materials developed. Achieving this objective was possible thanks to a properly design of the strategy followed together with complete characterization of the nanostructures prepared. In a first part of this Thesis, the nanostructuration of Fe(II)-based switchable systems with spin crossover behaviour was achieved by following two different strategies. On the one hand, a top-down methodology based on liquid-phase exfoliation was applied for the isolation of 2D flakes from the bulk crystal. On the other hand, through a bottom-up approach, the synthesis of novel nanoparticles was possible by modulating the reaction diffusion using microfluidic based methodologies. In both cases, the nanostructured materials were integrated in polymeric matrices to evaluate their potential application as proof-of-concept thermochromic films. In the second part of the Thesis, a novel family of nanoscale coordination polymers (NCPs) based on Fe(III), Gd(III), Mn(II), In(III) and Cu(II) was stablished through its rational synthesis by using one-pot reaction. The nanoparticles obtained were validated by pre-clinical in vivo tests showing interesting performance as potential theranostic agents for imaging (Magnetic resonance imaging, positron emission tomography and single-photon emission computed tomography) and potential pre-treatment of glioblastoma and lung diseases

    Membrane à base de catécholamine, son procédé de préparation et ses utilisations

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    [EN] The present invention provides a process for preparing a self-standing catecholamine-based membrane, the process comprising the steps of: (a) cross-linking a catechol derivative with an amine selected from the group consisting of: a known aliphatic amine hydrocarbon of formula (II); and an aromatic amine of formula (IIbis), in a liquid medium, wherein both the catechol and the amine are soluble, at a pH comprised from 6.5 to 10, and under appropriate agitation to create a catecholamine membrane in the air/liquid interface in the absence of any support; and b) isolating the membrane resulting from step (a) from the air/liquid interface. The resulting self-standing catecholamine-based membrane was robust, easy to handle and manipulate, highly flexible and adaptable to any kind of surface without breaking, and adhesive. In addition, the free-standing membrane of the invention shows a Janus character, with an unexpected nanopatterning in the water-contact side which endows the membranes of the invention with a higher roughness surface, something of value to promote cell adhesion.[FR] La présente invention concerne un procédé de préparation d'une membrane à base de catécholamine autoportante, le procédé comprenant les étapes consistant : (A) à réticuler un dérivé de catéchol avec une amine choisie dans le groupe constitué : d'un hydrocarbure d'amine aliphatique connu de formule (II) ; et d'une amine aromatique de formule (IIbis), dans un milieu liquide, le catéchol et l'amine étant tous les deux solubles, à un pH compris entre 6,5 et 10, et sous agitation appropriée afin de créer une membrane de catécholamine dans l'interface air/liquide en l'absence de tout support ; et b) à isoler la membrane résultant de l'étape (a) de l'interface air/liquide. La membrane à base de catécholamine autoportante obtenue était robuste, facile à manier et à manipuler, hautement flexible et adaptable à tout type de surface sans rupture, et adhésive. De plus, la membrane autoportante de l'invention présente un caractère Janus, possédant une nanostructuration inattendue sur le côté en contact avec l'eau qui confère aux membranes de l'invention une surface de rugosité plus élevée, ce qui est utile pour favoriser l'adhérence cellulaire.NoFundació Institut Català de Nanociència i Nanotecnología (ICN2), Consejo Superior de Investigaciones Científicas (CSIC)A1 Solicitud de patente con informe sobre el estado de la técnic
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