Examinando por Autor "Leyva-Parra, Luis"

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    B7Be6B7: A Boron-Beryllium Sandwich Complex
    (John Wiley and Sons Inc, 2023-08) Dong, Xue; Tiznado, William; Liu, Yu-qian; Leyva-Parra, Luis; Liu, Xin-bo; Pan, Sudip; Merino, Gabriel; Cui, Zhong-hua
    Planar boron clusters have often been regarded as “π-analogous” to aromatic arenes because of their similar delocalized π-bonding. However, unlike arenes such as C5H5− and C6H6, boron clusters have not previously shown the ability to form sandwich complexes. In this study, we present the first sandwich complex involving beryllium and boron, B7Be6B7. The global minimum of this combination adopts a unique architecture having a D6h geometry, featuring an unprecedented monocyclic Be6 ring sandwiched between two quasi-planar B7 motifs. The thermochemical and kinetic stability of B7Be6B7 can be attributed to strong electrostatic and covalent interactions between the fragments. Chemical bonding analysis shows that B7Be6B7 can be considered as a [B7]3−[Be6]6+[B7]3− complex. Moreover, there is a significant electron delocalization within this cluster, supported by the local diatropic contributions of the B7 and Be6 fragments. © 2023 The Authors. Angewandte Chemie International Edition published by Wiley-VCH GmbH.
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    Exploring the Potential Energy Surface of Medium-Sized Aromatic Polycyclic Systems with Embedded Planar Tetracoordinate Carbons: A Guided Approach
    (Multidisciplinary Digital Publishing Institute (MDPI), 2023-09) Inostroza, Diego; Leyva-Parra, Luis; Yañez, Osvaldo; Cooksy, Andrew L.; Thimmakondu, Venkatesan S.; Tiznado, William
    This study scrutinizes the complexities of designing and exploring the potential energy surfaces of systems containing more than twenty atoms with planar tetracoordinate carbons (ptCs). To tackle this issue, we utilized an established design rule to design a Naphtho [1,2-b:3,4-b′:5,6-b″:7,8-b′′′]tetrathiophene derivative computationally. This process began with substituting S atoms with CH− units, then replacing three sequential protons with two Si2+ units in the resultant polycyclic aromatic hydrocarbon polyanion. Despite not representing the global minimum, the newly designed Si8C22 system with four ptCs provided valuable insights into strategic design and potential energy surface exploration. Our results underscore the importance of employing adequate methodologies to confirm the stability of newly designed molecular structures containing planar hypercoordinate carbons. © 2023 by the authors.
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    Planar Elongated B12 Structure in M3B12 Clusters (M = Cu-Au)
    (MDPI, 2023-01) Solar-Encinas, José; Vásquez-Espinal, Alejandro; Leyva-Parra, Luis; Yañez, Osvaldo; Inostroza, Diego; Valenzuela, Maria Luisa; Orellana, Walter; Tiznado, William
    Here, it is shown that the M3B12 (M = Cu-Au) clusters’ global minima consist of an elongated planar B12 fragment connected by an in-plane linear M3 fragment. This result is striking since this B12 planar structure is not favored in the bare cluster, nor when one or two metals are added. The minimum energy structures were revealed by screening the potential energy surface using genetic algorithms and density functional theory calculations. Chemical bonding analysis shows that the strong electrostatic interactions with the metal compensate for the high energy spent in the M3 and B12 fragment distortion. Furthermore, metals participate in the delocalized π-bonds, which infers an aromatic character to these species. © 2022 by the authors.
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    Searching for Systems with Planar Hexacoordinate Carbons
    (MDPI, 2023-03) Inostroza, Diego; Leyva-Parra, Luis; Yañez, Osvaldo; Solar-Encinas, José; Vásquez-Espinal, Alejandro; Valenzuela, Maria Luisa; Tiznado, William
    Here, we present evidence that the D2h M2C50/2+ (M = Li-K, Be-Ca, Al-In, and Zn) species comprises planar hexacoordinate carbon (phC) structures that exhibit four covalent and two electrostatic interactions. These findings have been made possible using evolutionary methods for exploring the potential energy surface (AUTOMATON program) and the Interacting Quantum Atoms (IQA) methodology, which support the observed bonding interactions. It is worth noting, however, that these structures are not the global minimum. Nonetheless, incorporating two cyclopentadienyl anion ligands (Cp) into the CaC52+ system has enhanced the relative stability of the phC isomer. Moreover, cycloparaphenylene ([8]CPP) provides system protection and kinetic stability. These results indicate that using appropriate ligands presents a promising approach for expanding the chemistry of phC species. © 2023 by the authors.