Examinando por Autor "Spodine, Evgenia"

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    2-(2-pyridylamino)pyridinium tetrachloridozincate(II)
    (International Union of Crystallography, 2008-06-01) Venegas-Yazigi, Diego; Castillo, Carolina; Paredes-Garcia, Veronica; Vega, Andres; Spodine, Evgenia
    The structure of the title compound, (C10H10N3)(2)[ZnCl4], is composed of C10H9N3H+ ( DPAH(+)) cations and [ ZnCl4](2-) anions. The two pyridyl rings of DPAH+ are approximately coplanar, with a dihedral angle of 7.2 ( 2)degrees between their corresponding least-squares planes. The proton is disordered in a one-to-one ratio over the two chemically equivalent pyridyl N atoms. An intramolecular hydrogen bond is formed between the pyridinium H atom and the pyridyl N atom of the other pyridyl ring. The Zn atom lies on a twofold rotation axis. There are also some weak N-H center dot center dot center dot Cl hydrogen bonds. These interactions lead to the formation of an alternating zigzag chain in the solid state. The results clearly show that reducing agents normally used in hydrothermal syntheses, such as metallic zinc employed here, are also active in terms of coordination chemistry.
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    First copper(ii) phase M′0.2Mn0.8PS3·0.25H2O and analogous M′ = CoII, NiII and ZnII materials obtained by microwave assisted synthesis
    (Royal Society of Chemistry, 2015-07) Fuentealba, Pablo; Cortés, Catalina; Audebrand, Nathalie; Le Fur, Eric; Paredes-García, Verónica; Venegas-Yazigi, Diego; Manzur, Jorge; Spodine, Evgenia
    M′0.2Mn0.8PS3·0.25H2O materials are obtained by a mild microwave assisted reaction (M′ = CoII, NiII, CuII, ZnII), which permitted us to obtain the first copper(ii) bimetallic phase. All these materials have a lower energy gap and antiferromagnetic interactions with lower values of the Weiss constant, than that of the pristine phase MnPS3. © The Royal Society of Chemistry.
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    Spin Frustrated Pyrazolato Triangular CuII Complex: Structure and Magnetic Properties, an Overview
    (MDPI, 2023-06) Cañón-Mancisidor, Walter; Hermosilla-Ibáñez, Patricio; Spodine, Evgenia; Paredes-García, Verónica; Gómez-García, Carlos J.; Venegas-Yazigi, Diego
    The synthesis and structural characterization of a new triangular Cu3–μ3OH pyrazolato complex of formula, [Cu3(μ3−OH)(pz)3(Hpz)3][BF4]2 (1−Cu3), Hpz = pyrazole, is presented. The triangular unit forms a quasi-isosceles triangle with Cu–Cu distances of 3.3739(9), 3.3571(9), and 3.370(1) Å. This complex is isostructural to the hexanuclear complex [Cu3(μ3−OH)(pz)3(Hpz)3](ClO4)2]2 (QOPJIP). A comparative structural analysis with other reported triangular Cu3–μ3OH pyrazolato complexes has been carried out, showing that, depending on the pyrazolato derivative, an auxiliary ligand or counter-anion can affect the nuclearity and/or the dimensionality of the system. The magnetic properties of 1−Cu3 are analyzed using experimental data and DFT calculation. A detailed analysis was performed on the magnetic properties, comparing experimental and theoretical data of other molecular triangular Cu3–μ3OH complexes, showing that the displacement of the μ3−OH− from the Cu3 plane, together with the type of organic ligands, influences the nature of the magnetic exchange interaction between the spin-carrier centers, since it affects the overlap of the magnetic orbitals involved in the exchange pathways. Finally, a detailed comparison of the magnetic properties of 1−Cu3 and QOPJIP was carried out, which allowed us to understand the differences in their magnetic properties. © 2023 by the authors.
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    Structural and electronic properties of Polyoxovanadoborates containing the [V 12 B 18 O 60 ] core in different mixed valence states
    (MDPI Multidisciplinary Digital Publishing Institute, 2015-09) Hermosilla-Ibáñez, Patricio; Muñoz-Becerra, Karina; Paredes-García, Verónica; Fur, Eric Le; Spodine, Evgenia; Venegas-Yazigi, Diego
    This review summarizes all published data until April 2015 related to crystalline lattices formed by the [V 12 B 18 O 60 ] core, which generates polyanionic clusters with different degrees of protonation and mixed-valence ratios. The negative charge of this cluster is counterbalanced by different cations such as protonated amines, hydronium, and alkaline, and transition metal ions. The cluster is shown to form extended 1D, 2D, or 3D frameworks by forming covalent bonds or presenting hydrogen bond interactions with the present secondary cations. These cations have little influence on the solid state reflectance UV-visible spectra of the polyanionic cluster, but are shown to modify the FT-IR spectra and the magnetic behavior of the different reported species. ©. © 2015 by the authors.
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    Toward a Rational Design of 3d-4f Heterometallic Coordination Polymers based on Mixed Valence Copper Centers
    (American Chemical Society, 2019-12) Cruz, Carlos; Rubio, Francisco; Venegas-Yazigi, Diego; Audebrand, Nathalie; Calers, Christophe; Spodine, Evgenia; Paredes-García, Verónica
    In the present work, we report two new CuI/CuII-GdIII mixed valence heterometallic coordination polymers (HCP), [Gd(H2O)4CuIICuI(IDC)2] (1) and [Gd2(H2O)2(C2O4)2CuII(IDC)2CuI 2(4,4′-bipy)]·4.5H2O (2) obtained under solvothermal synthesis using 1H-imidazole-4,5-dicarboxylic acid (H3IDC) as a principal N,O-bifunctional organic linker. In both compounds, the stabilization of the CuI cations is achieved only by the coordination of N-Atoms belonging to the organic ligands. While 1 presents a two-dimensional honeycomb network obtained by the coordination of single organic linker (IDC3-), 2 contains three different organic ligands (IDC3-, C2O4 2-, and 4,4′-bipy), which allow the construction of a three-dimensional network. From a magnetic point of view, 1 and 2 behave as simple paramagnets at high temperature, presenting ferromagnetic interactions below 50 K, and a positive magnetic coupling constant of J = 0.60 cm-1 and J = 0.22 cm-1 was obtained for 1 and 2 respectively. To the best our knowledge, 1 and 2 correspond to the second and third reported examples containing a CuI/CuII mixed valence system assembled with GdIII cations, thus enriching the chemistry involved in 3d-4f metal-organic materials. Copyright © 2019 American Chemical Society.
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    Trichromatic color tuning strategy for emission of heterometallic EuIII/TbIII coordination polymers with triazolyl-substituted 4-methyl-phenoxo ligand
    (Journal of Rare Earths, 2025, 2025) Perez-Obando, Juliana; Manzur, Jorge; Fuentealba, Pablo; Morales, Jeannette; Vega, Andrés; Costa de Santana, Ricardo; Carneiro Neto, Albano N.; Spodine, Evgenia
    This study presents the microwave-assisted synthesis and characterization of a series of heterometallic coordination polymers (HMCPs) with a 4-methyl-2,6-di[(1H-1,2,4-triazol-1-yl)]phenoxo ligand with varying EuIII/TbIII ratios. Single crystal X-ray diffraction reveals a double-chain structure bridged by triazolyl groups. Powder X-ray diffraction confirms the isostructural nature of the synthesized HMCPs. The photophysical properties depend on lanthanide ion concentration and excitation wavelength, leading to a color shift from green to blue as the proportion of TbIII decreases and EuIII increases. White light generation is achieved in the 8/2 EuIII/TbIII HMCP (CIE: 0.293, 0.326) under 335 nm excitation. The study suggests energy transfer from TbIII to EuIII, but both experimental and theoretical calculations indicate that this transfer is orders of magnitude lower than the sensitization through ligand states. © 2024 The Authors