Examinando por Autor "Ancede-Gallardo, Evys"

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  • Miniatura
    Ítem
    Comprehensive Structural, Electronic, and Biological Characterization of fac-[Re(CO)3(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)Br]: X-Ray, Aromaticity, Electrochemistry, and HeLa Cell Viability
    (MPDI, 2025-12-21) Carreño, Alexander; Artigas, Vania; Ancede-Gallardo, Evys; Morales-Guevara, Rosaly; Leyva-Parra, Luis; Luis Leyva-Parra; Martí, Angel A.; Videla, Camila; Otero, María Carolina; Gacitúa, Manuel
    The rhenium(I) tricarbonyl complex fac-[Re(CO)3(5,6-epoxy-5,6-dihydro-1,10-phenanthroline)Br] (ReL) has previously demonstrated promising luminescent properties, enabling its direct application as a probe for walled cells such as Candida albicans and Salmonella enterica. In this new study, we present a significantly expanded and comprehensive characterization of ReL, incorporating a wide range of experimental and computational techniques not previously reported. These include variable-temperature 1H and 13C NMR spectroscopy, CH-COSY, single-crystal X-ray diffraction, Hirshfeld surface analysis, DFT calculations, Fukui functions, non-covalent interaction (NCI) indices, and electrochemical profiling. Structural analysis confirmed a pseudo-octahedral geometry with the bromide ligand positioned cis to the epoxy group. NMR data revealed the coexistence of cis and trans isomers in solution, with the trans form being slightly more stable. DFT calculations and aromaticity descriptors indicated minimal electronic differences between isomers, supporting their unified treatment in subsequent analyses. Electrochemical studies revealed two oxidation and two reduction events, consistent with ECE and EEC mechanisms, including a Re(I) → Re(0) transition at −1.50 V vs. SCE. Theoretical redox potentials showed strong agreement with experimental data. Biological assays revealed a dose-dependent cytotoxic effect on HeLa cells, contrasting with previously reported low toxicity in microbial systems. These findings, combined with ReL’s luminescent and antimicrobial properties, underscore its multifunctional nature and highlight its potential as a bioactive and imaging agent for advanced therapeutic and microbiological applications.
  • Miniatura
    Ítem
    Influence of Iodine substitutions on the photophysical properties of rhenium(I) tricarbonyl complexes with pyridine schiff base (PSB-IHB)
    (Wiley, 2025-01-08) Morales-Guevara, Rosaly; Páez-Hernández, Dayán; Ancede-Gallardo, Evys; Carreño, Alexander
    This theoretical investigation aims to evaluate the influence of iodine substitutions on the phenolic moiety of the pyridine Schiff bases harboring an intramolecular hydrogen bond (PSB-IHB) ancillary ligand within the monocationic. fac-[Re(CO)3(N,N)(PSB-IHB)]+ architecture on photophysical properties, particularly emission range. Optimized structures of two Re(I) tricarbonyl complexes (C1 and C2) were analyzed, revealing a distorted octahedral coordination geometry. Geometric parameters were compared with experimental data from analogous complexes. NBO analysis confirmed the presence of intramolecular hydrogen bonds (IHBs) in both singlet and triplet states, providing significant stabilization. Theoretical calculations predicted three distinct absorption bands for all complexes in dichloromethane, indicating substantial electronic delocalization between the pyridinic and phenolic rings via the azomethine group. These findings underscore the crucial role of delocalization and donor–acceptor interactions in stabilizing Re(I) tricarbonyl complexes and their impact on photophysical properties. Emissions calculated for the C1 and C2 complexes were observed within the range of 632–643 nm. The presence of IHBs was found to be essential for modulating photophysical properties, with emissions attributed to ligand-to-ligand charge transfer transitions.