Examinando por Autor "Pan, Sudip"

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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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    Dynamical behavior of Borospherene: A Nanobubble
    (Nature Publishing Group, 2015-06) Martínez-Guajardo, Gerardo; Cabellos, José Luis; Díaz-Celaya, Andres; Pan, Sudip; Islas, Rafael; Chattaraj, Pratim K.; Heine, Thomas; Merino, Gabriel
    The global minimum structure of borospherene (B40) is a cage, comprising two hexagonal and four heptagonal rings. Born-Oppenheimer Molecular Dynamics simulations show that continuous conversions in between six and seven membered rings take place. The activation energy barrier for such a transformation is found to be 14.3 kcal·mol-1. The completely delocalized σ - and π-frameworks, as well as the conservation of the bonding pattern during rearrangement, facilitate the dynamical behavior of B40. B40 is predicted to act as a support-free spherical two-dimensional liquid at moderate temperature. In other words, B40 could be called as a nanobubble. © 2015 Macmillan Publishers Limited.
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    Effects of temperature on enantiomerization energy and distribution of isomers in the chiral cu13 cluster
    (MDPI, 2021-09) Castillo-Quevedo, Cesar; Buelna-Garcia, Carlos Emiliano; Paredes-Sotelo, Edgar; Robles-Chaparro, Eduardo; Zamora-Gonzalez, Edgar; Martin-Del-campo-solis, Martha Fabiola; Quiroz-Castillo, Jesus Manuel; Del-Castillo-Castro, Teresa; Martínez-Guajardo, Gerardo; De Leon flores, Aned; Cortez Valadez, Manuel; Ortiz Chi, Filiberto; Gaxiola, Tulio; Castillo, Santos Jesus; Vásquez Espinal, Alejandro; Pan, Sudip; Cabellos, Jose Luis
    In this study, we report the lowest energy structure of bare Cu13 nanoclusters as a pair of enantiomers at room temperature. Moreover, we compute the enantiomerization energy for the interconversion from minus to plus structures in the chiral putative global minimum for temperatures ranging from 20 to 1300 K. Additionally, employing nanothermodynamics, we compute the probabilities of occurrence for each particular isomer as a function of temperature. To achieve that, we explore the free energy surface of the Cu13 cluster, employing a genetic algorithm coupled with density functional theory. Moreover, we discuss the energetic ordering of isomers computed with various density functionals. Based on the computed thermal population, our results show that the chiral putative global minimum strongly dominates at room temperature. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
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    Planar pentacoordinate s-block metals
    (Royal Society of Chemistry, 2023-07) Wang, Meng-Hui; Kalita, Amlan J.; Orozco-Ic, Mesías; Yan, Gai-Ru; Chen, Chen; Yan, Bing; Castillo-Toraya, Gabriela; Tiznado, William; Guha, Ankur K.; Pan, Sudip; Merino, Gabriel; Cui, Zhong-Hua
    The presence of a delocalized π-bond is often considered an essential criterion for achieving planar hypercoordination. Herein, we show that σ-delocalization could be sufficient to make the planar configuration the most stable isomer in a series of planar pentacoordinate s-block metals. High-level ab initio computations reveal that the global minimum of a series of interalkali and interalkali-alkaline earth clusters (LiNa5, Li5Mg+, Na5Mg+, K5Ca+, CaRb5+, Rb5Sr+, and SrCs5+) adopts a singlet D5h structure with a planar pentacoordinate lithium or alkaline earth metal (AE = Mg, Ca, Sr). These clusters are unusual combinations to stabilize a planar pentacoordinate atom, as all their constituents are electropositive. Despite the absence of π-electrons, Hückel's rule is fulfilled by the six σ-electrons. Furthermore, the systems exhibit a diatropic ring current in response to an external magnetic field and a strong magnetic shielding, so they might be classified as σ-aromatic. Therefore, multicenter σ-bonds and the resulting σ-delocalization stabilize these clusters, even though they lack π-aromaticity. © 2023 The Royal Society of Chemistry.