6 research outputs found

    2D-Coordination polymers based on 1H-indazole4-carboxylic acid and transition metal ions: magnetic, luminescence and biological properties

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    We report the formation of five novel multifunctional coordination polymers based on 1H-indazole-4- carboxylic acid (HL). To the best of our knowledge, these complexes are the first examples of coordination compounds constructed with this interesting ligand. These materials were synthesized by solvothermal routes, possess different 2D-structures and show interesting magnetic properties due to the copper compound showing an unusual spin-canted effect while the anisotropic cobalt material behaves as a fieldinduced single molecule magnet. MTT assays performed on human embryonic kidney (HEK293) and mouse skin melanoma (B16-F10) cell lines indicated that the Cd-based compound was the only one exhibiting dose-dependent toxicity on B16-F10 cells, most likely due to the release of toxic Cd(II). Cadmium and zinc polymers exhibit interesting luminescence properties. The fact that zinc polymers did not exhibit inherent toxicity against both cancer and non-cancerous cells make this new family an excellent candidate for further investigation in the field of luminescent materials with biomedical applications.Junta de Andalucia FQM-394 FQM-1484Red Guipuzcoana de Ciencia, Tecnologia e Innovacion OF218/2018University of Basque Country GIU 17/13Basque Government IT1005-16Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) PGC2018-102052-A-C22 PGC2018-102052-B-C21Junta de Andalucia FQM-394 FQM-1484European Union (EU)ESFGovernment of the Basque CountryFEDER/MCIU/AEI RYC-2016-21042 JdC-201

    Dilution effect on the slow relaxation of a luminescent dysprosium Metal-Organic Framework based on 2,5-dihydroxyterephthalic acid

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    A new dysprosium based Metal-Organic Framework with {[Dy(dhbdc)(DMF)]·DMF} formula has been obtained from solvothermal reaction with 2,5-dihydroxyterephthalic acid ligand and dysprosium chloride. This coordination polymer has been characterized and its crystal structure has been solved by X-ray diffraction methods elucidating a three-dimensional network. Magnetic studies of this compound reveal the existence of weak antiferromagnetic interactions among the metal ions with θ value of −0.26 K. Dynamic ac magnetic susceptibility measurements were carried out under an external dc field of 1 kOe, highlighting that at high frequencies two relaxation processes can be observed. However, when studying the diamagnetically diluted analogue 1, a single relaxation process was detected highlighting the effect of the weak but not negligible exchange interactions. Finally, photoluminescence measurements were performed at different temperatures with the aim of getting a more representative characterization of the emissive performance of the material for potential applications in lighting and thermometry.Financial support was given by Junta de Andalucía (Spain) (project number FQM-394 and FQM-1484), University of the Basque Country (GIU 17/13), Gobierno Vasco/Eusko Jaurlaritza (IT1005-16) and the Spanish Ministry of Economy and Competitiveness (MCIU/AEI/FEDER, UE) (PGC2018-102052-A-C22, PGC2018-102052-B-C21 and CTQ-2015-64049-C3-3R). The authors thank for technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF). A.Z.-L. is grateful to the Government of the Basque Country for the predoctoral fellowshi

    Photoluminescent coordination polymers based on group 12 metals and 1h-indazole-6-carboxylic acid.

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    Two new coordination polymers (CPs) based on Zn(II) and Cd(II) and 1H-indazole-6-carboxylic acid (H L) of general formulae [Zn(L)(H O)] (1) and [Cd (HL) ] (2) have been synthe-sized and fully characterized by elemental analyses, Fourier transformed infrared spectroscopy and single crystal X-ray diffraction. The results indicate that compound 1 possesses double chains in its structure whereas 2 exhibits a 3D network. The intermolecular interactions, including hydrogen bonds, C–H···π and π···π stacking interactions, stabilize both crystal structures. Photoluminescence (PL) properties have shown that compounds 1 and 2 present similar emission spectra compared to the free-ligand. The emission spectra are also studied from the theoretical point of view by means of time-dependent density-functional theory (TD-DFT) calculations to confirm that ligand-centred π-π* electronic transitions govern emission of compound 1 and 2. Finally, the PL properties are also studied in aqueous solution to explore the stability and emission capacity of the compounds.Financial support was given by Junta de Andalucía (Spain) (FQM-394), University of the Basque Country (GIU 17/13), Gobierno Vasco/Eusko Jaurlaritza (IT1005-16), and the Spanish Ministry of Science, Innovation and Universities (MCIU/AEI/FEDER, UE) (PGC2018-102052-A-C22, PGC2018-102052-B-C21). J.M.D.L. and G.B.R.R. acknowledge the FEDER/MCIU/AEI for their Ramón y Cajal (RYC-2016-21042) and Juan de la Cierva (JdC-2017) fellowships, respectively. S.R. acknowledges the Juan de la Cierva Incorporación Fellowship (grant agreement no. IJC2019-038894-I). E.E.-E. is grateful to the Government of the Basque Country for the predoctoral fellowship. The authors thank for technical and human support provided by SGIker of UPV/EHU and European funding (ERDF and ESF)

    Antiparasitic, anti-inflammatory and cytotoxic activities of 2D coordination polymers based on 1H-indazole-5-carboxylic acid

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    We report on the formation of two novel multifunctional isomorphous (4,4) square-grid 2D coordination polymers based on 1H-indazole-5-carboxylic acid. To the best of our knowledge, these complexes are the first examples of 2D-coordination polymers constructed with this novel ligand. We have analysed in detail the structural, magnetic and anti-parasitic properties of the resulting materials. In addition, the capability of inhibiting nitric oxide production from macrophage cells has been measured and was used as an indirect measure of the anti-inflammatory response. Finally, the photocatalytic activity was measured with a model pollutant, i.e. vanillic acid (phenolic compound), with the aim of further increasing the functionalities and applicability of the compounds

    Heterogeneous contributions of change in population distribution of body mass index to change in obesity and underweight

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    From 1985 to 2016, the prevalence of underweight decreased, and that of obesity and severe obesity increased, in most regions, with significant variation in the magnitude of these changes across regions. We investigated how much change in mean body mass index (BMI) explains changes in the prevalence of underweight, obesity, and severe obesity in different regions using data from 2896 population-based studies with 187 million participants. Changes in the prevalence of underweight and total obesity, and to a lesser extent severe obesity, are largely driven by shifts in the distribution of BMI, with smaller contributions from changes in the shape of the distribution. In East and Southeast Asia and sub-Saharan Africa, the underweight tail of the BMI distribution was left behind as the distribution shifted. There is a need for policies that address all forms of malnutrition by making healthy foods accessible and affordable, while restricting unhealthy foods through fiscal and regulatory restrictions. © Copyright
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