Single-Ion Magnets Based on Mononuclear Cobalt(II) Complexes with Sulfadiazine

The already reported monomeric complex Co(SDZ)2bpy (1) and the new ternary complex Co(SDZ)2(6MQ)2 (2) (SDZ = sulfadiazine, bpy = 2,2′‐bipyridine, and 6MQ = 6‐methoxyquinoline) have been synthesized in order to study their magnetic properties. X‐ray diffraction studies indicate that in both compounds the SDZ acts as a bidentate ligand coordinating through the sulfonamide and the pyrimidine N atoms giving rise to a CoN6 coordination sphere. The complexes have been characterized based on elemental analyses, FTIR, UV/Vis spectroscopy, and thermogravimetric analysis (TGA, only for 2). Compounds 1 and 2 have been characterized magnetically, and they show slow relaxation of the magnetization below 9 and 6 K, respectively.Centro de Química InorgánicaInstituto de Física La Plat

Crystal structure, physicochemical properties, Hirshfeld surface analysis and antibacterial activity assays of transition metal complexes of 6-methoxyquinoline

Five monomeric complexes of Co(ii), Cu(ii), Ni(ii), Zn(ii) and Ag(i) with 6-methoxyquinoline (6-MeOQ) as ligand have been prepared, and their crystal structures have been determined by single X-ray diffractions. The Cu(ii), Ni(ii) and Zn(ii) complexes are formulated as M(6-MeOQ) 2 Cl 2 , completing MN 2 Cl 2 coordination spheres. On the other hand, Co(ii) and Ag(i) compounds are ionic with formulae [Ag(6-MeOQ) 2 ] + NO 3 - and H(6-MeOQ) + [Co(6-MeOQ)Cl 3 ] - (where H(6-MeOQ) + is the protonated ligand). Hirshfeld surface analysis was employed to study the intermolecular interactions in the crystal lattices and from these studies it was found that π-stacking contacts play an important role. Besides, the complexes have been characterized by FTIR, UV-visible and emission spectroscopies. The singlet oxygen production and fluorescence quantum yields were measured for all the complexes employing steady-state methodologies. Finally, the antibacterial activity of the complexes was screened against both Gram-positive and Gram-negative bacteria.Fil: Villa Perez, Cristian. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Ortega, I.C.. Universidad Nacional de Colombia; ColombiaFil: Vélez Macías, Andrea. Universidad Nacional de Colombia; ColombiaFil: Payán, A. M.. Universidad Nacional de Colombia; ColombiaFil: Echeverría, Gustavo Alberto. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Soria, Delia Beatriz. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; ArgentinaFil: Valencia Uribe, Gloria Cristina. Universidad Nacional de Colombia; Colombi

Crystal structure, physicochemical properties, Hirshfeld surface analysis and antibacterial activity assays of transition metal complexes of 6-methoxyquinoline

Five monomeric complexes of Co(ii), Cu(ii), Ni(ii), Zn(ii) and Ag(i) with 6-methoxyquinoline (6-MeOQ) as ligand have been prepared, and their crystal structures have been determined by single X-ray diffractions. The Cu(ii), Ni(ii) and Zn(ii) complexes are formulated as M(6-MeOQ) 2 Cl 2 , completing MN 2 Cl 2 coordination spheres. On the other hand, Co(ii) and Ag(i) compounds are ionic with formulae [Ag(6-MeOQ) 2 ] + NO 3 - and H(6-MeOQ) + [Co(6-MeOQ)Cl 3 ] - (where H(6-MeOQ) + is the protonated ligand). Hirshfeld surface analysis was employed to study the intermolecular interactions in the crystal lattices and from these studies it was found that π-stacking contacts play an important role. Besides, the complexes have been characterized by FTIR, UV-visible and emission spectroscopies. The singlet oxygen production and fluorescence quantum yields were measured for all the complexes employing steady-state methodologies. Finally, the antibacterial activity of the complexes was screened against both Gram-positive and Gram-negative bacteria.Centro de Química InorgánicaInstituto de Física La Plat

6-Methoxyquinoline complexes as lung carcinoma agents: induction of oxidative damage on A549 monolayer and multicellular spheroid model

The aim of this work was to study the antitumor effects and the mechanisms of toxic action of a series of 6-methoxyquinoline (6MQ) complexes in vitro. The Cu(II) and Zn(II) complexes (Cu6MQ and Zn6MQ) are formulated as M(6MQ) 2 Cl 2 ; the Co(II) and Ag(I) compounds (Co6MQ and Ag6MQ) are ionic with formulae [Ag(6MQ) 2 ] + NO 3 − and H(6MQ) + [Co(6MQ)Cl 3 ] − (where H(6MQ) + is the protonated ligand). We found that the copper complex, outperformed the Co(II), Zn(II) and Ag(I) complexes with a lower IC 50 (57.9 µM) in A549 cells exposed for 24 h. Cu6MQ decreased cell proliferation and induced oxidative stress detected with H 2 DCFDA at 40 µM, which reduces GSH/GSSG ratio. This redox imbalance induced oxidative DNA damage revealed by the Micronucleus test and the Comet assay, which turned into a cell cycle arrest at G2/M phase and induced apoptosis. In multicellular spheroids, the IC 50 values tripled the monolayer model (187.3 µM for 24 h). At this concentration, the proportion of live/dead cells diminished, and the spheroids could not proliferate or invade. Although Zn6MQ also decreased GSH/GSSG ratio from 200 µM and the cytotoxicity is related to oxidative stress, the induction of the hydrogen peroxide levels only doubled the control value. Zn6MQ induced S phase arrest, which relates with the increased micronucleus frequency and with the induction of necrosis. Finally, our results reveal a synergistic activity with a 1:1 ratio of both complexes in the monolayer and multicellular spheroids.Fil: Cadavid Vargas, Juan Fernando. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas; ArgentinaFil: Villa Perez, Cristian. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Ruiz, M. C.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Leon, Ignacio Esteban. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Valencia Uribe, Gloria Cristina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Soria, Delia Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Etcheverry, Susana Beatriz. Universidad Nacional de Colombia; Colombia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Di Virgilio, Ana Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; Argentin

6-Methoxyquinoline complexes as lung carcinoma agents: induction of oxidative damage on A549 monolayer and multicellular spheroid model

The aim of this work was to study the antitumor effects and the mechanisms of toxic action of a series of 6-methoxyquinoline (6MQ) complexes in vitro. The Cu(II) and Zn(II) complexes (Cu6MQ and Zn6MQ) are formulated as M(6MQ)₂Cl₂; the Co(II) and Ag(I) compounds (Co6MQ and Ag6MQ) are ionic with formulae [Ag(6MQ)₂]⁺NO₃⁻ and H(6MQ)⁺[Co(6MQ)Cl₃]⁻ (where H(6MQ)⁺ is the protonated ligand). We found that the copper complex, outperformed the Co(II), Zn(II) and Ag(I) complexes with a lower IC₅₀ (57.9 µM) in A549 cells exposed for 24 h. Cu6MQ decreased cell proliferation and induced oxidative stress detected with H₂DCFDA at 40 µM, which reduces GSH/GSSG ratio. This redox imbalance induced oxidative DNA damage revealed by the Micronucleus test and the Comet assay, which turned into a cell cycle arrest at G2/M phase and induced apoptosis. In multicellular spheroids, the IC₅₀ values tripled the monolayer model (187.3 µM for 24 h). At this concentration, the proportion of live/dead cells diminished, and the spheroids could not proliferate or invade. Although Zn6MQ also decreased GSH/GSSG ratio from 200 µM and the cytotoxicity is related to oxidative stress, the induction of the hydrogen peroxide levels only doubled the control value. Zn6MQ induced S phase arrest, which relates with the increased micronucleus frequency and with the induction of necrosis. Finally, our results reveal a synergistic activity with a 1:1 ratio of both complexes in the monolayer and multicellular spheroids.Facultad de Ciencias ExactasCentro de Química Inorgánic

Balance de 25 años de jurisprudencia de la Corte Constitucional

La Corte Constitucional de Colombia ha tenido un importante impacto en la vida social, cultural y política del país, a tal punto que, desde su creación, la jurisprudencia de este tribunal se ha convertido en un referente mundial acerca de las diversas materias sobre las que se ha pronunciado . Este libro presenta un balance de la jurisprudencia que durante sus primeros veinticinco años la Corte ha expedido. Con este fin, el magistrado Luis Guillermo Guerrero Pérez y los magistrados auxiliares Miguel Polo Rosero y Claudia Escobar García recogen los trabajos de expertos nacionales e internacionales, funcionarios del Estado y Miembros de la sociedad civil que se presentaron en el XII Encuentro de la Jurisdicción Constitucional, realizado en la ciudad de San Juan de Pasto entre el 27 y el 30 de septiembre de 2017. En ese encuentro, se ratificó que la Corte Constitucional tiene la tarea de velar por la integridad de los compromisos de la Constitución. Los capítulos que conforman este libro ofrecen una mirada multidisciplinaria sobre la eficacia y el impacto de las decisiones de la Corte, específicamente en lo que tiene que ver con la democracia y la participación, el sistema de salud, el sistema pensional, el medio ambiente y el fenómeno discriminatorio con la relación al género y a la condición de discapacidad en Colombia.Bogot

4-nonilfenol: efectos, cuantificación y métodos de remoción en aguas superficiales y potables

The emergent contaminants are a group of non-regulated substances with low concentrations that cause irreversible damage to ecosystems and have been mostly identified as endocrine disruptors, so have gained great interest in the last 20 years. To mitigate its impact and presence in ecosystems, alternatives have been proposed to achieve their removal, such as adsorption, electrocoagulation, membrane filtration and advanced oxidation processes (AOP). 4- nonylphenol (4-NF) is used as a precursor in the manufacture of nonionic surfactants for use in detergents, dispersing, emulsifying, pesticide formulations, paints and personal care products, so its main access road to the environment it is by sewage, however, has become increasingly important environmental level, by various effects generated when entering aquatic ecosystems and the variety of isomers which can be found in the environment. In this review information about some physicochemical properties of 4-NF, toxicity, quantification method considering analytical and instrumental conditions, and methods of removal is collected.Los contaminantes emergentes constituyen un grupo de sustancias cuya regulación está siendo abordada, debido al incremento de su presencia en cuerpos de agua asociado principalmente a las acciones antropogénicas. Estos compuestos caracterizados como disruptores endocrinos a bajas concentraciones causan daños irreversibles en los ecosistemas y están siendo objeto de estudio especialmente en las últimas dos décadas. Para mitigar su impacto y presencia en los ecosistemas, se han estudiado alternativas para lograr su remoción, basadas en procesos de adsorción, electrocoagulación, filtración por membrana y procesos de oxidación avanzada (AOP). Específicamente el contaminante emergente 4-nonilfenol (4-NF), compuesto perteneciente a la familia de los alquilfenoles, es utilizado como principio activo de tensoactivos no iónicos para uso en detergentes, dispersantes, emulsionantes y solubilizantes, estando presente entre otros, en formulaciones producto de aseo, de plaguicidas y de pinturas, siendo su principal vía de acceso al ambiente a través de aguas residuales. Esta revisión bibliográfica reúne información acerca de algunas propiedades fisicoquímicas del 4-NF, toxicidad, métodos de cuantificación y remoció

4-nonilfenol: efectos, cuantificación y métodos de remoción en aguas superficiales y potables

The emergent contaminants are a group of non-regulated substances with low concentrations that cause irreversible damage to ecosystems and have been mostly identified as endocrine disruptors, so have gained great interest in the last 20 years. To mitigate its impact and presence in ecosystems, alternatives have been proposed to achieve their removal, such as adsorption, electrocoagulation, membrane filtration and advanced oxidation processes (AOP). 4- nonylphenol (4-NF) is used as a precursor in the manufacture of nonionic surfactants for use in detergents, dispersing, emulsifying, pesticide formulations, paints and personal care products, so its main access road to the environment it is by sewage, however, has become increasingly important environmental level, by various effects generated when entering aquatic ecosystems and the variety of isomers which can be found in the environment. In this review information about some physicochemical properties of 4-NF, toxicity, quantification method considering analytical and instrumental conditions, and methods of removal is collected.Los contaminantes emergentes constituyen un grupo de sustancias cuya regulación está siendo abordada, debido al incremento de su presencia en cuerpos de agua asociado principalmente a las acciones antropogénicas. Estos compuestos caracterizados como disruptores endocrinos a bajas concentraciones causan daños irreversibles en los ecosistemas y están siendo objeto de estudio especialmente en las últimas dos décadas. Para mitigar su impacto y presencia en los ecosistemas, se han estudiado alternativas para lograr su remoción, basadas en procesos de adsorción, electrocoagulación, filtración por membrana y procesos de oxidación avanzada (AOP). Específicamente el contaminante emergente 4-nonilfenol (4-NF), compuesto perteneciente a la familia de los alquilfenoles, es utilizado como principio activo de tensoactivos no iónicos para uso en detergentes, dispersantes, emulsionantes y solubilizantes, estando presente entre otros, en formulaciones producto de aseo, de plaguicidas y de pinturas, siendo su principal vía de acceso al ambiente a través de aguas residuales. Esta revisión bibliográfica reúne información acerca de algunas propiedades fisicoquímicas del 4-NF, toxicidad, métodos de cuantificación y remoció

Estudio preliminar de la cascarilla de arroz modificada y su efecto en la adsorción de Cr(VI) en solución

Introduction. There are several studies that affirm that rice husk has a good adsorption capacity in an aqueous solution for removing Cr(VI). On the other hand, the Fenton reagent leads to the formation of hydroxyl radicals, considered as highly oxidant species, and this has brought their wide application in water treatments. Concerning the rice husk, a waste from agricultural industries, it is regarded as an environmental problem given its accumulation, but this waste contains a lot of lignin, cellulose, hemicellulose and silicon oxides and, therefore, it is an efficient natural adsorbent to remove heavy metals. The chemical modification of these materials´ surfaces increases the adsorption capacity of metals in solutions. Objective. Determine the conditions for the modification reaction of rice husk with the Fenton reagent and establish the effect on the removal of Cr(VI) in aqueous solution before and after the modification. Materials and methods. The effect of variables such as initial pH, [Fe+2]/[H2O2] ratio and time of the reactants were analyzed in order to establish the best conditions for the modification. Then, a 2k factorial analysis was performed with the initial metal concentration (C), acidity of the medium (pH) and adsorbent´s dosage (D) variables, in order to establish the changes in terms of removal percentages. Results. It was demonstrated that with a lower dose of the contaminant (0.7 ppm), the removal percentages reached 90% in both the modified and the native husks. Conclusions. This research work demonstrated the structural modification of rice husk and the Fenton reagent and also demonstrated that, as the Cr(VI) is increased, the removal percentage is lower. Therefore, the Cr(VI) concentration is a significant variable in the metals´ removal in a solution and, the other way around, the dose of the adsorbent in the ratio used is not a significant variable in the model obtained.Introdução. Se há reportado estudos que asseguram que a casca de arroz tem uma boa capacidade adsortiva em solução aquosa para a remoção de Cr(VI). Por outro lado, o reativo de Fenton conduz à formação de radicais hidroxilos, considerados espécies altamente oxidantes o qual há permitido sua amplia aplicação para o tratamento de águas. No caso da casca de arroz, resíduo da agroindústria, é considerado um problema meio-ambiental devido a sua acumulação, mas, estes resíduos possuem grandes quantidades de lignina, celulosa, hemicelulosa e óxidos de silício, por isto é considerado um adsorvente natural eficaz para a remoção de metais pesados. A modificação química da superfície destes materiais aumenta a capacidade adsortiva de metais em solução. Objetivo. Determinar as condições para a reação de modificação da casca de arroz com o reativo de Fenton e estabelecer o efeito sobre a remoção de Cr(VI) em solução aquosa prévio e posterior à modificação. Materiais e métodos. Se analisou o efeito de variáveis como o pH inicial, relação [Fe+2]/[H2O2], e tempo dos reagentes, para estabelecer as melhores condições para a modificação. Posteriormente, se realizou uma análise fatorial 2k com as variáveis concentração inicial do metal (C), acidez do meio (pH) e dose do adsorvente (D) para estabelecer as mudanças em termos de porcentagem de remoção. Resultados. Se evidenciou que a menor dose de contaminante utilizada (0.7 ppm) as porcentagens de remoção alcançaram um 90 % tanto na casca modificada como na nativa. Conclusões. Nesta investigação, se demostrou a modificação estrutural da casca de arroz com o reativo de Fenton e ao incrementar a dose de Cr(VI) se reduz a porcentagem de remoção, encontrando que a concentração do Cr(VI) é uma variável significativa na remoção do metal em solução, contrário a isto, a dose do adsorvente na faixa utilizada, não é uma variável significativa no modelo obtido.Introducción. Se ha reportado estudios que aseguran que la cascarilla de arroz tiene una buena capacidad adsortiva en solución acuosa para la remoción de Cr(VI). Por otro lado, el reactivo de Fenton conduce a la formación de radicales hidroxilos, considerados especies altamente oxidantes lo cual ha permitido su amplia aplicación para el tratamiento de aguas. En el caso de la cascarilla de arroz, desecho de la agroindustria, es considerado un problema medioambiental debido a su acumulación, sin embargo, estos residuos poseen grandes cantidades de lignina, celulosa, hemicelulosa y óxidos de silicio, por ello es considerado un adsorbente natural eficaz para la remoción de metales pesados. La modificación química de la superficie de estos materiales aumenta la capacidad adsortiva de metales en solución. Objetivo. Determinar las condiciones para la reacción de modificación de la cascarilla de arroz con el reactivo de Fenton y establecer el efecto sobre la remoción de Cr(VI) en solución acuosa previo y posterior a la modificación. Materiales y métodos. Se analizó el efecto de variables como el pH inicial, relación [Fe+2]/ [H2O2], y tiempo de los reaccionantes, para establecer las mejores condiciones para la modificación. Posteriormente, se realizó un análisis factorial 2k con las variables concentración inicial del metal (C), acidez del medio (pH) y dosificación del adsorbente (D) para establecer los cambios en términos de porcentaje de remoción. Resultados. Se evidenció que a menor dosis de contaminante utilizada (0.7 ppm) los porcentajes de remoción alcanzaron un 90 % tanto en la cascarilla modificada como en la nativa. Conclusiones. En esta investigación, se demostró la modificación estructural de la cascarilla de arroz con el reactivo de Fenton y al incrementar la dosis de Cr(VI) se reduce el porcentaje de remoción, encontrando que la concentración del Cr(VI) es una variable significativa en la remoción del metal en solución, contrario a ello, la dosificación del adsorbente en el rango utilizado, no es una variable significativa en el modelo obtenido