Browsing by Autor "Marietta Vizcaya"

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    Síntesis y caracterización de complejos metálicos de Cu(II), Zn(II) y Sm(II) con ácido itacónico
    (Universidad de Los Andes, 2020) Amal El‐Halah; Valeria Boide-Trujillo; Marcela Erder-Concordia; Marietta Vizcaya; Gerzón E. Delgado; Francisco López‐Carrasquero
    In this work, the synthesis in alcoholic solution and characterization of Cu(II), Zn(II), and Sm(III) metal complexes with the itaconic acid are presented. All materials were characterized by the FT-IR and UV spectroscopy, thermogravimetric analysis (TGA), thermal volatilization analysis (TVA), conductimetry, and powder diffraction. FT-IR and UV-visible anal-yses suggest a monodentate coordination for the zinc and copper complexes and thermogravimetric results indicate the presence of two water molecules in the structure with a stoichiometry Zn(C5H4O4)·2H2O and Cu(C5H4O4)·2H2O, respec-tively, where the ligand is the acid carboxylate (C5H4O4). For the samarium complex an ionic structure with a Sm2(C5H4O4)3·4H2O stoichiometry is suggested. The X-ray diffraction study indicates that the Cu and Zn complexes crys-tallize in monoclinic cells with space group P21/c.
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    Síntesis y caracterización de hidrazonas obtenidas a partir de 1,2 y 1,4-naftoquinona con 2,4-dinitrofenilhidracina
    (Universidad de Los Andes, 2021) Jesús Ramón Briceño Barrios; Marietta Vizcaya; Freddy A. Carrillo; Gerzón E. Delgado
    In this work, the results of the synthesis and characterization of 1,2- and 1,4-naphthoquinone derivatives with 2,4-dinitrophenylhidrazine in alcoholic solution are presented. The products [1] and [2] were characterized by FT-IR, UV-visible and H1-NMR spectroscopy and X-ray diffraction. The spectroscopic analyzes indicate the formation of the expected hydrazones. X-ray powderdiffraction study indicated that both compounds crystallizes in monoclinic cells, space group P21/c andunit cell parameters: a =16.3541(7) A, b =12.8648(6) A, c =6.9195(1) A, s =100.140(2)°, V =1433.08(9) A3, an-da =7.3274(2) A, b =16.3523(7) A, c =11.1187(5) A, s =99.266(4)°, V =1314.86(9) A3, for [1] and [2] derivatives, respec-tively.