Browsing by Author "Romero, Elkin L."
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Item (E)-5-[1-Hydroxy-3-(3,4,5-trimethoxyphenyl)allylidene]-1,3-dimethylpyrimidine-2,4,6-trione: Crystal structure and Hirshfeld surface analysis(International Union of Crystallography, 2017-07-13) Soto-Monsalve, Mónica; Romero, Elkin L.; Zuluaga, Fabio; Chaur, Manuel N.; D'Vries, Richard F.In the title compound, C18H20N2O7, the dihedral angle between the aromatic rings is 7.28 (7)° and the almost planar conformation of the molecule is supported by an intramolecular O - H⋯O hydrogen bond, which closes an S(6) ring. In the crystal, weak C - H⋯O hydrogen bonds and aromatic π-π stacking link the molecules into a three-dimensional network. A Hirshfeld surface analysis showed that the major contribution to the intermolecular interactions are van der Waals interactions (H⋯H contacts), accounting for 48.4% of the surface. © Soto-Monsalve et al. 2017.Item (E)-5-[1-Hydroxy-3-(3,4,5-trimethoxyphenyl)allylidene]-1,3-dimethylpyrimidine-2,4,6-trione: crystal structure and Hirshfeld surface analysis(Acta Crystallographica Section E: Structure Reports Online, 2017) Soto-Monsalve, Mónica; Romero, Elkin L.; Zuluaga, Fabio; Chaur, Manuel N.; D’Vries, Richard F.In the title compound, C 18 H 20 N 2 O 7 , the dihedral angle between the aromatic rings is 7.28 (7)° and the almost planar conformation of the molecule is supported by an intramolecular O—H...O hydrogen bond, which closes an S (6) ring. In the crystal, weak C—H...O hydrogen bonds and aromatic π–π stacking link the molecules into a three-dimensional network. A Hirshfeld surface analysis showed that the major contribution to the intermolecular interactions are van der Waals interactions (H...H contacts), accounting for 48.4% of the surface.Item New pyrazolino and pyrrolidino[60]fullerenes: the introduction of the hydrazone moiety for the formation of metal complexes(Journal of Physical Organic Chemistry, 2016) Romero, Elkin L.; Cabrera-Espinoza, Andrea; Ortiz-Peña, Nathaly; Soto-Monsalve, Mónica; Zuluaga, Fabio; D’Vries, Richard F.; Chaur, Manuel N.The [3 + 2] cycloaddition reaction of C60 with pyridine-derived hydrazones (acting as dipolar reagents) was successfully conducted resulting in fullerene derivatives 5a, 5b. The compounds were characterized by means of NMR, UV–Vis spectroscopy, and X-ray crystallography. The electrochemical behavior was also investigated. The fulleropyrazoline 5a exhibits anodically shifted reduction potentials of about 100 mV when compared with those for C60, whereas 5b exhibits cathodic shifts relative to pristine C60. The complexation reaction of 5b with metallic ions (Zn2+, Cd2+, and Fe2+) was achieved. Job and Benesi–Hildebrand analysis confirmed the formation of complexes with a molar ratio of 1:1 and binding constants between 2.26 × 105 and 1.59 × 105 M−1. Electrochemistry of these complexes showed a marked influence of the metal ion on the reduction potentials.Item Structural, spectroscopic, and theoretical analysis of a molecular system based on 2-((2-(4- chlorophenylhydrazone)methyl)quinolone(Universidad Nacional de Colombia, 2018-12-02) Romero, Elkin L.; Soto-Monsalve, Mónica; Gutiérrez, Gustavo; Zuluaga, Fabio; D'Vries, Richard F.; Chaur, Manuel N.A novel molecular system based on 2-((2-(4-chlorophenylhydrazone)methyl)quinoline (1-E) was synthesized. Interconversion of 1-E to its configurational isomer 1-Z was achieved using UV radiation (250 W Hg lamp). Such isomerization was monitored by1H-NMR. The results suggest that the hydrazone derivative can act as a chemical brake in solution. This molecular system was structurally (Single Crystal X-Ray diffraction and DFT calculations) and spectroscopically (NMR, UV, and IR) characterized. Electrochemical measurements showed that configurational changes induce differential redox behavior. In this regard, the reported quinoline system exhibits different dynamic absorption and electrochemical properties that are modulated by UV-light. Therefore, 1-E can be regarded as a potential photo-electrochemical switch. © 2018, Universidad Nacional de Colombia. All rights reserved.