Examinando por Autor "Pino-Rios, Ricardo"
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Ítem Cluster Assembled Silicon-Lithium Nanostructures: A Nanowire Confined Inside a Carbon Nanotube(Frontiers Media S.A., 2021-11) Orellana, Walter; Pino-Rios, Ricardo; Yañez, Osvaldo; Vásquez Espinal, Alejandro; Peccati, Francesca; Contreras García, Julia; Cardenas, Carlos; Tiznado, WilliamWe computationally explore an alternative to stabilize one-dimensional (1D) silicon-lithium nanowires (NWs). The Li12Si9 Zintl phase exhibits the NW (Formula presented.), combined with Y-shaped Si4 structures. Interestingly, this NW could be assembled from the stacking of the Li6Si5 aromatic cluster. The (Formula presented.) @CNT nanocomposite has been investigated with density functional theory (DFT), including molecular dynamics simulations and electronic structure calculations. We found that van der Waals interaction between Li’s and CNT’s walls is relevant for stabilizing this hybrid nanocomposite. This work suggests that nanostructured confinement (within CNTs) may be an alternative to stabilize this free NW, cleaning its properties regarding Li12Si9 solid phase, i.e., metallic character, concerning the perturbation provided by their environment in the Li12Si7 compound. Copyright © 2021 Orellana, Pino-Rios, Yañez, Vásquez-Espinal, Peccati, Contreras-García, Cardenas and Tiznado.Ítem Electronic Transmutation Concept: Is the Inverse Process Possible? An Evaluation of Main Group Compounds(American Chemical Society, 2023-01) Báez-Grez, Rodrigo; Yáñez, Osvaldo; Pino-Rios, RicardoThe electronic transmutation (ET) concept states that when an element with atomic number Z gains an electron, it transmutes into a Z + 1 element, leading to species that possess similar chemical bonding patterns and geometric structures regarding the original (Z + 1) element. In this work, the opposite concept, that is, the inverse ET, is assessed. For this purpose, several main group compounds have been analyzed in terms of the adaptive natural density partitioning. The obtained results suggest that when an atom Z loses an electron, it transmutes into a Z − 1 atom, acquiring its geometrical structure and bonding pattern. © 2023 The Authors.Ítem Interpreting Aromaticity and Antiaromaticity through Bifurcation Analysis of the Induced Magnetic Field(ChemistryOpen, 2019-03) Pino-Rios, Ricardo; Cárdenas-Jirón, Gloria; Ruiz, Lina; Tiznado, WilliamIn all molecules, a current density is induced when the molecule is subjected to an external magnetic field. In turn, this current density creates a particular magnetic field. In this work, the bifurcation value of the induced magnetic field is analyzed in a representative set of aromatic, non-aromatic and antiaromatic monocycles, as well as a set of polycyclic hydrocarbons. The results show that the bifurcation value of the ring-shaped domain adequately classifies the studied molecules according to their aromatic character. For aromatic and nonaromatic molecules, it is possible to analyze two ring-shaped domains, one diatropic (inside the molecular ring) and one paratropic (outside the molecular ring). Meanwhile, for antiaromatic rings, only a diatropic ring-shaped domain (outside the molecular ring) is possible to analyze, since the paratropic domain (inside the molecular ring) is irreducible with the maximum value (attractor) at the center of the molecular ring. In some of the studied cases, i. e., in heteroatomic species, bifurcation values do not follow aromaticity trends and present some inconsistencies in comparison to ring currents strengths, showing that this approximation provides only a qualitative estimation about (anti)aromaticity.Ítem Kick-Fukui: A Fukui Function-Guided Method for Molecular Structure Prediction(American Chemical Society, 2021-08-23) Yañez, Osvaldo; Báez-Grez, Rodrigo; Inostroza, Diego; Pino-Rios, Ricardo; Rabanal-León, Walter A.; Contreras-García, Julia; Cardenas, Carlos; Tiznado, WilliamHere, we introduce a hybrid method, named Kick-Fukui, to explore the potential energy surface (PES) of clusters and molecules using the Coulombic integral between the Fukui functions in the first screening of the best individuals. In the process, small stable molecules or clusters whose combination has the stoichiometry of the explored species are used as assembly units. First, a small set of candidates has been selected from a large and stochastically generated (Kick) population according to the maximum value of the Coulombic integral between the Fukui functions of both fragments. Subsequently, these few candidates are optimized using a gradient method and density functional theory (DFT) calculations. The performance of the program has been evaluated to explore the PES of various systems, including atomic and molecular clusters. In most cases studied, the global minimum (GM) has been identified with a low computational cost. The strategy does not allow to identify the GM of some silicon clusters; however, it predicts local minima very close in energy to the GM that could be used as the initial population of evolutionary algorithms. ©Ítem On the Importance of Noncovalent Interactions in the Stabilization of Nonconventional Compounds Using Bulky Groups(American Chemical Society, 2023-06) Báez-Grez, Rodrigo; Pino-Rios, RicardoIn this article, we studied the capability of bulky groups to contribute to the stabilization of a given compound in addition to the well-known steric effect related to substituents due to their composition (alkyl chains and aromatic groups, among others). For this purpose, the recently synthesized 1-bora-3-boratabenzene anion which contains large substituents was analyzed by means of the independent gradient model (IGM), natural population analysis (NPA) at the TPSS/def2-TZVP level, force field-based energy decomposition analysis (EDA-FF) applying the universal force field (UFF), and molecular dynamics calculations under the GFN2-xTB approach. The results indicate that the bulky groups should not only be considered for their steric effects but also for their ability to stabilize a system that could be very reactive. © 2023 The Authors. Published by American Chemical Society.Ítem Searching for double σ- And π-aromaticity in borazine derivatives(Royal Society of Chemistry, 2020-08) Pino-Rios, Ricardo; Vásquez-Espinal, Alejandro; Yañez, Osvaldo; Tiznado, WilliamInspired by the double-aromatic (σ and π) C6H3+, C6I62+, and C6(SePh)62+ ring-shaped compounds, herein we theoretically study their borazine derivative analogues. The systems studied are the cation and dications with formulas B3N3H3+, B3N3Br62+, B3N3I62+, B3N3(SeH)62+, and B3N3(TeH)62+. Our DFT calculations indicate that the ring-shaped planar structures of B3N3H3+, B3N3I62+, and B3N3(TeH)62+ are more stable in the singlet state, while those of B3N3Br62+ and B3N3(SeH)62+ prefer the triplet state. Besides, exploration of the potential energy surface shows that the ring-shaped structure is the putative global minimum only for B3N3I62+. According to chemical bonding analysis, B3N3H3+, B3N3I62+, and B3N3(TeH)62+ have σ and π delocalized bonds. The number of delocalized σ/π electrons is 2/6 for the first, and 10/6 for the second and third, similar to what their carbon analogs exhibit. Finally, the analysis of the magnetically induced current density allows B3N3H3+, B3N3I62+, and B3N3(TeH)62+ to be classified as strongly σ aromatic, and poorly π aromatic compounds. © The Royal Society of Chemistry.