Browsing by Author "Ramos-Hernandez, Andrea"

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    Effect of the introduction of ethylenedioxythiophene and styrilnitroisooxazol groups on the properties and photovoltaic performances of tryphenylamine based π -conjugated push-pull molecules
    (2024) Arteaga, Gean C.; Louarn, Guy; Ramos-Hernandez, Andrea; Romero, Mario; Arzel, Ludovic; Bernede, Jean Christian; Saavedra-Olavarria, Jorge; Perez, Edwin G.; Maza, Julio R.; Romero, Jonathan; Cattin, Linda
    Properties of pi-conjugated push-pull molecules based on triphenylamine have been modified through the introduction of ethylenedioxythiophene and a styrilnitroisooxazol group. It is shown that the obtained new molecule called GC8 exhibits light absorption in the visible, between 400 nm and 700 nm and a high hole mobility of 210-5 cm2V- 1s- 1, which places this organic donor among those with good mobility in this family of compounds. It behaves as electron donor in organic photovoltaic cells, with a HOMO of 5.35 eV, a LUMO of 2.94 eV which gives a band gap of 2.41 eV, these values being obtained from theoretical estimation using TD-DFT theory. The measured experimental optical band gap is 1.9 eV, this difference in value between theory and experiment is reasonable for small molecules. GC8 has been introduced as electron donor in planar heterojunctions organic photovoltaic cells (PHJ-OPVs), fullerenes (C60 or C70) being used as electron acceptor. It is shown that the optimum GC8 layer thickness is 20 nm, while a 5 min annealing at 100 degrees C improves the power conversion efficiency (PCE) by 10%. The high light absorption of C70 allows improving cells performances compared to that using C60, the champion cell having a 6.15% efficiency. The PCE improvement after the annealing is due to an increase of the hole mobility and optical absorption.
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    Predicting the Adsorption of Amoxicillin and Ibuprofen on Chitosan and Graphene Oxide Materials: A Density Functional Theory Study
    (2021) Anchique, Leonardo; Alcazar, Jackson J.; Ramos-Hernandez, Andrea; Mendez-Lopez, Maximiliano; Mora, Jose R.; Rangel, Norma; Luis Paz, Jose; Marquez, Edgar
    The occurrence, persistence, and accumulation of antibiotics and non-steroidal anti-inflammatory drugs (NSAIDs) represent a new environmental problem due to their harmful effects on human and aquatic life. A suitable absorbent for a particular type of pollutant does not necessarily absorb other types of compounds, so knowing the compatibility between a particular pollutant and a potential absorbent before experimentation seems to be fundamental. In this work, the molecular interactions between some pharmaceuticals (amoxicillin, ibuprofen, and tetracycline derivatives) with two potential absorbers, chitosan and graphene oxide models (pyrene, GO-1, and coronene, GO-2), were studied using the omega B97X-D/6-311G(2d,p) level of theory. The energetic interaction order found was amoxicillin/chitosan > amoxicillin/GO-1 > amoxicillin/GO-2 > ibuprofen/chitosan > ibuprofen/GO-2 > ibuprofen/GO-1, the negative sign for the interaction energy in all complex formations confirms good compatibility, while the size of E-int between 24-34 kcal/mol indicates physisorption processes. Moreover, the free energies of complex formation were negative, confirming the spontaneity of the processes. The larger interaction of amoxicillin Gos, compared to ibuprofen Gos, is consistent with previously reported experimental results, demonstrating the exceptional predictability of these methods. The second-order perturbation theory analysis shows that the amoxicillin complexes are mainly driven by hydrogen bonds, while van der Waals interactions with chitosan and hydrophobic interactions with graphene oxides are modelled for the ibuprofen complexes. Energy decomposition analysis (EDA) shows that electrostatic energy is a major contributor to the stabilization energy in all cases. The results obtained in this work promote the use of graphene oxides and chitosan as potential adsorbents for the removal of these emerging pollutants from water.
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    Synthesis, Photophysical Properties, Theoretical Studies, and Living Cancer Cell Imaging Applications of New 7-(Diethylamino)quinolone Chalcones
    (2024) Insuasty, Daniel; Mutis, Mario; Trilleras, Jorge; Illicachi, Luis A.; Rodriguez, Juan D.; Ramos-Hernandez, Andrea; San-Juan-Vergara, Homero G.; Cadena-Cruz, Christian; Mora, Jose R.; Paz, Jose L.; Mendez-Lopez, Maximiliano; Perez, Edwin G.; Aliaga, Margarita E.; Valencia, Jhesua; Marquez, Edgar
    In this article, three unsymmetrical 7-(diethylamino)quinolone chalcones with D-pi-A-D and D-pi-A-pi-D type push-pull molecular arrangements were synthesized via a Claisen-Schmidt reaction. Using 7-(diethylamino)quinolone and vanillin as electron donor (D) moieties, these were linked together through the alpha,beta-unsaturated carbonyl system acting as a linker and an electron acceptor (A). The photophysical properties were studied, revealing significant Stokes shifts and strong solvatofluorochromism caused by the ICT and TICT behavior produced by the push-pull effect. Moreover, quenching caused by the population of the TICT state in THF-H2O mixtures was observed, and the emission in the solid state evidenced a red shift compared to the emission in solution. These findings were corroborated by density functional theory (DFT) calculations employing the wb97xd/6-311G(d,p) method. The cytotoxic activity of the synthesized compounds was assessed on BHK-21, PC3, and LNCaP cell lines, revealing moderate activity across all compounds. Notably, compound 5b exhibited the highest activity against LNCaP cells, with an LC50 value of 10.89 mu M. Furthermore, the compounds were evaluated for their potential as imaging agents in living prostate cells. The results demonstrated their favorable cell permeability and strong emission at 488 nm, positioning them as promising candidates for cancer cell imaging applications.