83 research outputs found
Highlighting Recent Crystalline Engineering Aspects of Luminescent Coordination Polymers Based on F-Elements and Ditopic Aliphatic Ligands
Three principal factors may influence the final structure of coordination polymers (CPs): (i) the nature of the ligand, (ii) the type and coordination number of the metal center, and (iii) the reaction conditions. Further, flexible carboxylate aliphatic ligands have been widely employed as building blocks for designing and synthesizing CPs, resulting in a diverse array of materials with exciting architectures, porosities, dimensionalities, and topologies as well as an increasing number of properties and applications. These ligands show different structural features, such as torsion an-gles, carbon backbone number, and coordination modes, which affect the desired products and so enable the generation of polymorphs or crystalline phases. Additionally, due to their large coordination numbers, using 4f and 5f metals as coordination centers combined with aliphatic ligands increases the possibility of obtaining different crystal phases. Additionally, by varying the synthetic conditions, we may control the production of a specific solid phase by understanding the thermo-dynamic and kinetic factors that influence the self-assembly process. This revision highlights the relationship between the structural variety of CPs based on flexible carboxylate aliphatic ligands and f-elements (lanthanide and actinides) and their outstanding luminescent properties such as solid-state emissions, sensing, and photocatalysis. In this sense, we present a structural analysis of the CPs reported with the oxalate ligand, as the one rigid ligand of the family, and other flexible dicarboxylate linkers with –CH2– spacers. Additionally, the nature of the luminescence properties of the 4f or 5f-CPs is analyzed, and finally, we present a novel set of CPs using a glutarate-derived ligand and samarium, with the formula [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2]•(2,2′-bipy) (α-Sm) and [2,2′-bipyH][Sm(HFG)2 (2,2′-bipy) (H2O)2] (β-Sm).Fil: D'Vries, Richard F.. Universidad Santiago de Cali; ColombiaFil: Gomez, Germán Ernesto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Ellena, Javier Alcides. Universidade de Sao Paulo; Brasi
¡Todos satisfechos! Alimentación en Quilichao, 1910 - 1950.
Se estudian las dinámicas ligadas a la alimentación en el municipio de Santander de Quilichao y su relación con la constitución de una lógica alimentaria que persistiera desde iniciado el siglo XX hasta la mitad del mismo. A lo largo de este recorrido se espera poder mostrar las interrelaciones que conforman la rutina alimentaria, el tipo de productos agrícolas y pecuarios que permitían la subsistencia cotidiana, así como la disposición de los excedentes en los mercados bajo una lógica comercial. Se aborda una metodología cualitativa de carácter descriptivo-analítico con la revisión de los archivos locales serán fuente de gran importancia, archivos del concejo, notariales, contrastados con documentos referenciados en el Archivo General de la Nación y otros fondos documentales de carácter nacional. De igual manera se incorporarán las entrevistas realizadas a diferentes actores sociales que vivieron en los periodos abordados en este estudio y quienes son transmisores de las memorias vivas del pueblo Quilichagueño.MaestríaMAGISTER EN HISTORI
Application of metal − organic frameworks
The burgeoning field of metal-organic frameworks or porous coordination polymers has received increasing interest in recent years. In the last decade these microporous materials have found several applications including storage and separation of gases, sensors, catalysis and functional materials. In order to better design new metal-organic frameworks and porous coordination polymers with specific functionalities a fundamental issue is to achieve a basic understanding of the relationship between molecular parameters and structures, preferred adsorption sites and properties by using using modern theoretical methods. The focus of this mini-review is a description of the potential and emerging applications of metal-organic framework
Chain-like uranyl-coordination polymer as a bright green light emitter for sensing and sunlight driven photocatalysis
A new uranyl-coordination polymer (UCP) has been solvothermally synthesized employing succinic acid and 1,10-phenanthroline (phen) as ligands. The obtained compound with the formula [(UO2)2(phen)(succ)0.5(OH)(O)4(μ3-O)(H2O)]·H2O (UNSL-1) is classified as 1D chains showing I0O1 connectivity. Also, the asymmetric unit is composed of two hepta-coordinated uranyl centers: U1 is surrounded by five oxygen atoms from succinate, while U2 is surrounded by two nitrogen atoms from phen and three oxygen atoms from succinate ([U1O7] and [U2N2O5]). The secondary-building unit (SBU) is composed of a sharing edge tetrameric cluster linked with a succinate ligand in the [-1 0 1] direction. Besides, the chains are reinforced by π-π stacking interactions between the aromatic rings of the phen molecules to conform a 2D supramolecular arrangement. Moreover, photoluminescence experiments show strong green emission consistent with uranyl crystalline materials. Photophysical characterization was completed via low-temperature measurements (77 K) and recording the decay emission for calculating the lifetime (τobs) value. Regarding its multifunctional properties, a cation-sensing performance was achieved showing selective quenching toward iron ions in aqueous media. Finally, UNSL-1 was tested as an efficient water photocatalyst for dye degradation under simulated sunlight irradiation, exhibiting promising results for organic-pollutant water remediation.Fil: Gomez, Germán Ernesto. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Onna, Diego Ariel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; Argentina. Universidad Nacional de San Martin. Instituto de Nanosistemas; ArgentinaFil: D'vries, R. F.. Universidad del Cauca; ColombiaFil: Barja, Beatriz Carmen. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Química, Física de los Materiales, Medioambiente y Energía. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Química, Física de los Materiales, Medioambiente y Energía; ArgentinaFil: Ellena, Javier Alcides. Universidade de Sao Paulo; BrasilFil: Narda, Griselda Edith. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; Argentina. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Departamento de Química; ArgentinaFil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martin. Instituto de Nanosistemas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin
Order-disorder phase transition induced by proton transfer in a co-crystal of 2,4-dichlorobenzoic acid and trimethylamine N-oxide
The crystalline binary adduct between the trimethylamine N-oxide (TMANO) and 2,4-dichlorobenzoic acid (2,4-DCBA) molecules was obtained by slow evaporation from acetonitrile. The obtained molecular complex is formed by a racemic mixture of molecular complexes crystallizing in the orthorhombic space group Pbca. An exhaustive analysis of the temperature dependence of the cell parameters and the behavior of the acidic hydrogen position and carboxilate group were studied by single crystal and powder X-ray diffraction, FT-IR spectroscopy and theoretical calculations. The molecular system was thermally characterized, subsequently demonstrating a order-disorder transition. Finally, the intermolecular interactions were analyzed via Hirshfeld surface analysis
Lanthanide coordination polymers with pyridyl-N-oxide or carboxylate functionalised host ligands
Elaboração de uma proposta de ficha - roteiro para uso no atendimento ao Pré-natal pela Equipe de Saúde da Família Luxemburgo do município de Sete Lagoas, Minas Gerais
O presente estudo teve como finalidade elaborar uma ficha-roteiro para uso no atendimento às consultas de pré-natal realizadas pelos profissionais da equipe de Estratégia em Saúde da Família (ESF) Luxemburgo do município de Sete Lagoas, Minas Gerais. Durante a realização do diagnóstico situacional a equipe verificou a necessidade de padronizar o atendimento prestado às gestantes. O Sistema Único de Saúde - SUS definiu um conjunto de regras para garantir a adequada prestação de assistência à gestante de forma clara, incluindo consultas e exames de rotina. Diante disso, o plano de intervenção teve como objetivo elaborar um formulário que atuasse como um roteiro norteador das consultas de pré-natal de rotina para auxiliar os profissionais que participam do atendimento à gestante, fornecendo maior clareza e organização em relação às informações, de forma a possibilitar a melhora na qualidade dos cuidados prestados às gestantes
Luminescence, chemical sensing and mechanical properties of crystalline materials based on lanthanide–sulfonate coordination polymers
Lanthanide-coordination polymers (Ln-CPs) constitute relevant compounds for the design of multifunctional materials. Nevertheless, studies devoted to an understanding of the relationships of combined structural-optical-mechanical properties have scarcely been reported. In this work, an exhaustive study of a series of CPs obtained from lanthanide metals, 3-hydroxinaphthalene-2,7-disulfonate (3-OHNDS) and 1,10-phenanthroline (Phen) as ligands is presented. Two crystalline phases were identified with the general formulae [Eu(3-OHNDS)(Phen)(H2O)]·3H2O (phase 1-Eu), and [Ln2(3-OHNDS)2(Phen)2(H2O)]·3H2O (phase 2-Ln), where Ln3+ = Tb, Dy, Ho, Er and Yb. Both phases were characterized by powder and single crystal X-ray diffraction, vibrational and thermal analysis and scanning electron microscopy. Moreover, nanoindentation analysis was performed in order to find the relationships between these structural features and the mechanical properties of the crystalline materials. The photoluminescence (PL) properties of the reported phases were also explored, involving excitation-emission experiments and quantification of color emission. Finally, one compound was selected as a chemical sensor model, exhibiting different optical behaviour in the presence of aromatic molecules, principally towards naphtalene molecules. These results make these compounds promising materials for the elaboration of selective chemical sensors.Fil: D'Vries, Richard F.. Universidade de Sao Paulo; BrasilFil: Gomez, Germán Ernesto. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Lionello, Diego Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Fuertes, Maria Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes; ArgentinaFil: Soler Illia, Galo Juan de Avila Arturo. Universidad Nacional de San Martín; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Ellena, Javier Alcides. Universidade de Sao Paulo; Brasi
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