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Cui LJ, Li Y, Leyva-Parra L, Tiznado W, Pan S, Cui ZH. Revisiting the Structure and Bonding in Li 5H 6- and the Exploration of Reactivity: Planar Pentacoordinate Hydrogen. J Phys Chem A 2024; 128:4806-4813. [PMID: 38839423 DOI: 10.1021/acs.jpca.4c02684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/07/2024]
Abstract
Recently, Guha and co-workers (Sarmah, K.; Kalita, A.; Purkayastha, S.; Guha, A. K. Pushing The Extreme of Multicentre Bonding: Planar Pentacoordinate Hydride. Angew. Chem. Int. Ed. 2024, e202318741) reported a highly intriguing bonding motif: planar pentacoordinate hydrogen (ppH) in Li5H6-, featuring C2v symmetry in the singlet state with two distinct H-Li (center-ring) bond distances. We herein revisited the potential energy surface of Li5H6- by using a target-oriented genetic algorithm. Our investigation revealed that the lowest-energy structure of Li5H6- exhibits a ppH configuration with very high D5h symmetry and a 1A1' electronic state. We did not find any electronic effect like Jahn-Teller distortion that could be responsible for lowering its symmetry. Moreover, our calculations demonstrated significant differences in the relative energies of other low-lying isomers. An energetically very competitive planar tetracoordinate hydrogen (ptH) isomer is also located, but it corresponds to a very shallow minimum on the potential energy surface depending on the used level of theory. Chemical bonding analyses, including AdNDP and EDA-NOCV, uncover that the optimal Lewis structure for Li5H6- involves H- ions stabilized by the Li5H5 crown. Surprisingly, despite the dominance of electrostatic interactions, the contribution from covalent bonding is also significant between ppH and the Li5H5 moiety, derived from H-(1s) → Li5H5 σ donation. Magnetically induced current density analysis revealed that due to minimal orbital overlap and the highly polar nature of the H-Li covalent interaction, the ppH exhibits local diatropic ring currents around the H centers, which fails to result in a global aromatic ring current. The coordination of Li5H6- with Lewis acids, BH3 and BMe3, instantly converts the ppH configuration to (quasi) ptH. These Lewis acid-bound ptH complexes show high electronic stability and high thermochemical stability against dissociation and, therefore, will be ideal candidates for the experimental realization.
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Affiliation(s)
- Li-Juan Cui
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Yahui Li
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Luis Leyva-Parra
- Centro de Química Teórica & Computacional (CQT&C), Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, Santiago de Chile 8370146, Chile
| | - William Tiznado
- Centro de Química Teórica & Computacional (CQT&C), Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, Santiago de Chile 8370146, Chile
| | - Sudip Pan
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
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2
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Jin YX, Guo JC. XB 2Bi 2 (X = Si, Ge, Sn, Pb): Penta-Atomic Planar Tetracoordinate Si/Ge/Sn/Pb Clusters with 20 Valence Electrons. Int J Mol Sci 2024; 25:2819. [PMID: 38474066 DOI: 10.3390/ijms25052819] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 02/24/2024] [Accepted: 02/26/2024] [Indexed: 03/14/2024] Open
Abstract
Planar tetracoordinate silicon, germanium, tin, and lead (ptSi/Ge/Sn/Pb) species are scarce and exotic. Here, we report a series of penta-atomic ptSi/Ge/Sn/Pb XB2Bi2 (X = Si, Ge, Sn, Pb) clusters with 20 valence electrons (VEs). Ternary XB2Bi2 (X = Si, Ge, Sn, Pb) clusters possess beautiful fan-shaped structures, with a Bi-B-B-Bi chain surrounding the central X core. The unbiased density functional theory (DFT) searches and high-level CCSD(T) calculations reveal that these ptSi/Ge/Sn/Pb species are the global minima on their potential energy surfaces. Born-Oppenheimer molecular dynamics (BOMD) simulations indicate that XB2Bi2 (X = Si, Ge, Sn, Pb) clusters are robust. Bonding analyses indicate that 20 VEs are perfect for the ptX XB2Bi2 (X = Si, Ge, Sn, Pb): two lone pairs of Bi atoms; one 5c-2e π, and three σ bonds (two Bi-X 2c-2e and one B-X-B 3c-2e bonds) between the ligands and X atom; three 2c-2e σ bonds and one delocalized 4c-2e π bond between the ligands. The ptSi/Ge/Sn/Pb XB2Bi2 (X = Si, Ge, Sn, Pb) clusters possess 2π/2σ double aromaticity, according to the (4n + 2) Hückel rule.
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Affiliation(s)
- Yan-Xia Jin
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Jin-Chang Guo
- Key Laboratory of Materials for Energy Conversion and Storage of Shanxi Province, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
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Hannah TJ, Chitnis SS. Ligand-enforced geometric constraints and associated reactivity in p-block compounds. Chem Soc Rev 2024; 53:764-792. [PMID: 38099873 DOI: 10.1039/d3cs00765k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
The geometry at an element centre can generally be predicted based on the number of electron pairs around it using valence shell electron pair repulsion (VSEPR) theory. Strategies to distort p-block compounds away from these predicted geometries have gained considerable interest due to the unique structural outcomes, spectroscopic properties or reactivity patterns engendered by such distortion. This review presents an up-to-date group-wise summary of this exciting and rapidly growing field with a focus on understanding how the ligand employed unlocks structural features, which in turn influences the associated reactivity. Relevant geometrically constrained compounds from groups 13-16 are discussed, along with selected stoichiometric and catalytic reactions. Several areas for advancement in this field are also discussed. Collectively, this review advances the notion of geometric tuning as an important lever, alongside electronic and steric tuning, in controlling bonding and reactivity at p-block centres.
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Affiliation(s)
- Tyler J Hannah
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2, Canada.
| | - Saurabh S Chitnis
- Department of Chemistry, Dalhousie University, 6274 Coburg Road, Halifax, NS, B3H 4R2, Canada.
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Gohain N, Bordoloi A, Kalita AJ, Guha AK. Rare Spin Avoided σ-σ Diradical Planar Tetracoordinate Boron Cluster: A Proto-Star for Planar Pentacoordination. Chemphyschem 2023; 24:e202300101. [PMID: 37409624 DOI: 10.1002/cphc.202300101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 04/11/2023] [Accepted: 07/06/2023] [Indexed: 07/07/2023]
Abstract
We report a global planar star-like cluster B3 Li3 featuring three planar tetracoordinate boron centres with a rare spin avoided σ-σ diradical character. The cluster was found to be stable towards dissociation into different fragments. The spin density was found to be localized solely on the three boron atoms in the molecular plane. This spin avoided σ-σ diradical character leads to the extension of the coordination number to yield a neutral B3 Li3 H3 and a cationic B3 Li3 H3 + cluster with three planar pentacoordinate boron centres in their global minimum structures. The planar geometry of the aninonic B3 Li3 H3 - cluster is slightly higher in energy. The planar global clusters were found to maintain planarity in their ligand protected benzene bound complexes, B3 Li3 (Bz)3 , B3 Li3 H3 (Bz)3 and B3 Li3 H3 (Bz)3 + with high ligand dissociation energies offering candidature for experimental detection.
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Affiliation(s)
- Namrata Gohain
- Advanced Computational Chemistry Centre, Cotton University, Panbazar, Guwahati, Assam, INDIA-, 781001
| | - Abhik Bordoloi
- Advanced Computational Chemistry Centre, Cotton University, Panbazar, Guwahati, Assam, INDIA-, 781001
| | - Amlan J Kalita
- Advanced Computational Chemistry Centre, Cotton University, Panbazar, Guwahati, Assam, INDIA-, 781001
| | - Ankur K Guha
- Advanced Computational Chemistry Centre, Cotton University, Panbazar, Guwahati, Assam, INDIA-, 781001
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Wang MH, Kalita AJ, Orozco-Ic M, Yan GR, Chen C, Yan B, Castillo-Toraya G, Tiznado W, Guha AK, Pan S, Merino G, Cui ZH. Planar pentacoordinate s-block metals. Chem Sci 2023; 14:8785-8791. [PMID: 37621437 PMCID: PMC10445469 DOI: 10.1039/d2sc05939h] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 07/14/2023] [Indexed: 08/26/2023] Open
Abstract
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.
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Affiliation(s)
- Meng-Hui Wang
- Institute of Atomic and Molecular Physics, Jilin University Changchun 130023 China
| | - Amlan J Kalita
- Advanced Computational Chemistry Centre, Department of Chemistry, Cotton University Panbazar Guwahati Assam 781001 India
| | - Mesías Orozco-Ic
- Donostia International Physics Center (DIPC) 20018 Donostia Euskadi Spain
| | - Gai-Ru Yan
- Institute of Atomic and Molecular Physics, Jilin University Changchun 130023 China
| | - Chen Chen
- Institute of Atomic and Molecular Physics, Jilin University Changchun 130023 China
| | - Bing Yan
- Institute of Atomic and Molecular Physics, Jilin University Changchun 130023 China
| | - Gabriela Castillo-Toraya
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados Unidad Mérida. Km 6 Antigua Carretera a Progreso. Apdo. Postal 73, Cordemex 97310 Mérida Yucatan Mexico
| | - William Tiznado
- Centro de Química Teórica & Computacional (CQT&C), Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello Avenida República 275 Santiago Chile
| | - Ankur K Guha
- Advanced Computational Chemistry Centre, Department of Chemistry, Cotton University Panbazar Guwahati Assam 781001 India
| | - Sudip Pan
- Institute of Atomic and Molecular Physics, Jilin University Changchun 130023 China
| | - Gabriel Merino
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados Unidad Mérida. Km 6 Antigua Carretera a Progreso. Apdo. Postal 73, Cordemex 97310 Mérida Yucatan Mexico
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physics, Jilin University Changchun 130023 China
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University Changchun 130023 China
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Li YX, Bai LX, Guo JC. Ternary XBe 4H 5- (X = Si, Ge, Sn, Pb) Clusters: Planar Tetracoordinate Si/Ge/Sn/Pb Species with 18 Valence Electrons. Molecules 2023; 28:5583. [PMID: 37513457 PMCID: PMC10385292 DOI: 10.3390/molecules28145583] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/16/2023] [Accepted: 07/18/2023] [Indexed: 07/30/2023] Open
Abstract
As one of the important probes of chemical bonding, planar tetracoordinate carbon (ptC) compounds have been receiving much attention. Compared with ptC clusters, the heavier planar tetracoordinate silicon, germanium, tin, lead (ptSi/Ge/Sn/Pb) systems are scarcer and more exotic. The 18-valence-electron (ve)-counting is one important guide, though not the only rule, for the design of planar tetra-, penta-coordinate carbon and silicon clusters. The 18ve ptSi/Ge system is very scarce and needs to be expanded. Based on the isoelectronic principle and bonding similarity between the Al atom and the BeH unit, inspired by the previously reported ptSi global minimum (GM) SiAl42-, a series of ternary 18 ve XBe4H5- (X = Si, Ge, Sn, Pb) clusters were predicted with the ptSi/Ge/Sn/Pb centers. Extensive density functional theory (DFT) global minimum searches and high-level CCSD(T) calculations performed herein indicated that these ptSi/Ge/Sn/Pb XBe4H5- (X = Si, Ge, Sn, Pb) clusters were all true GMs on their potential energy surfaces. These GMs of XBe4H5- (X = Si, Ge, Sn, Pb) species possessed the beautiful fan-shaped structures: XBe4 unit can be stabilized by three peripheries bridging H and two terminal H atoms. It should be noted that XBe4H5- (X = Si, Ge, Sn, Pb) were the first ternary 18 ve ptSi/Ge/Sn/Pb species. The natural bond orbital (NBO), canonical molecular orbitals (CMOs) and adaptive natural densitpartitioning (AdNDP) analyses indicated that 18ve are ideal for these ptX clusters: delocalized one π and three σ bonds for the XBe4 core, three Be-H-Be 3c-2e and two Be-H σ bonds for the periphery. Additionally, 2π plus 6σ double aromaticity was found to be crucial for the stability of the ptX XBe4H5- (X = Si, Ge, Sn, Pb) clusters. The simulated photoelectron spectra of XBe4H5- (X = Si, Ge, Sn, Pb) clusters will provide theoretical basis for further experimental characterization.
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Affiliation(s)
- Yong-Xia Li
- Department of Chemistry, Xinzhou Teachers University, Xinzhou 034000, China
| | - Li-Xia Bai
- Nanocluster Laboratory Institute, Molecular Science Shanxi University, Taiyuan 030006, China
| | - Jin-Chang Guo
- Nanocluster Laboratory Institute, Molecular Science Shanxi University, Taiyuan 030006, China
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7
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σ-Aromaticity in planar pentacoordinate aluminium and gallium clusters. Sci Rep 2022; 12:10041. [PMID: 35710864 PMCID: PMC9203769 DOI: 10.1038/s41598-022-14430-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2022] [Accepted: 05/17/2022] [Indexed: 11/08/2022] Open
Abstract
Planar hypercoordinate structures are gaining immense attention due to the shift from common paradigm. Herein, our high level ab initio calculations predict that planar pentacoordinate aluminium and gallium centres in Cu5Al2+ and Cu5Ga2+ clusters are global minima in their singlet ground states. These clusters are thermodynamically and kinetically very stable. Detailed electronic structure analyses reveal the presence of σ-aromaticity which is the driving force for the stability of the planar form.
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8
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Sigmund LM, Maier R, Greb L. The inversion of tetrahedral p-block element compounds: general trends and the relation to the second-order Jahn-Teller effect. Chem Sci 2022; 13:510-521. [PMID: 35126983 PMCID: PMC8729809 DOI: 10.1039/d1sc05395g] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/14/2021] [Indexed: 12/31/2022] Open
Abstract
The tetrahedron is the primary structural motif among the p-block elements and determines the architecture of our bio- and geosphere. However, a broad understanding of the configurational inversion of tetrahedral compounds is missing. Here, we report over 250 energies (DLPNO-CCSD(T)) for square planar inversion of third- and fourth-period element species of groups 13, 14, and 15. Surprisingly low inversion barriers are identified for compounds of industrial relevance (e.g., ≈100 kJ mol-1 for Al(OH)4 -). More fundamentally, the second-order Jahn-Teller theorem is disclosed as suitable to rationalize substituent and central element effects. Bond analysis tools give further insights into the preference of eight valence electron systems with four substituents to be tetrahedral. Hence, this study develops a model to understand, memorize, and predict the angular flexibility of tetrahedral species. Perceiving the tetrahedron not as forcingly rigid but as a dynamic structural entity might leverage new approaches and visions for adaptive matter.
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Affiliation(s)
- Lukas M Sigmund
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Rouven Maier
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 270 69120 Heidelberg Germany
- Department of Chemistry and Biochemistry - Inorganic Chemistry, Freie Universität Berlin Fabeckstr. 34/36 14195 Berlin Germany
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9
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Chen C, Wang MH, Feng LY, Zhao LQ, Guo JC, Zhai HJ, Cui ZH, Pan S, Merino G. Bare and ligand protected planar hexacoordinate silicon in SiSb 3M 3+ (M = Ca, Sr, Ba) clusters. Chem Sci 2022; 13:8045-8051. [PMID: 35919428 PMCID: PMC9278486 DOI: 10.1039/d2sc01761j] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 06/10/2022] [Indexed: 11/21/2022] Open
Abstract
The global minimum of SiSb3M3+ (M = Ca, Sr, Ba) is a D3h symmetric structure containing an elusive planar hexacoordinate silicon (phSi) atom. Most importantly, the phSi core remains intact in ligand protected environment as well.
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Affiliation(s)
- Chen Chen
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130021, China
| | - Meng-hui Wang
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130021, China
| | - Lin-Yan Feng
- Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Lian-Qing Zhao
- Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Jin-Chang Guo
- Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Hua-Jin Zhai
- Nanocluster Laboratory, Institute of Molecular Science, Shanxi University, Taiyuan 030006, China
| | - Zhong-hua Cui
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130021, China
| | - Sudip Pan
- Fachbereich Chemie, Philipps-Universität Marburg, Hans-Meerwein-Strasse 4, 35032 Marburg, Germany
| | - Gabriel Merino
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, km 6 Antigua carretera a Progreso, Apdo. Postal 73, Cordemex 97310, Mérida, Yuc., Mexico
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10
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Wang MH, Chen C, Pan S, Cui ZH. Planar hexacoordinate gallium. Chem Sci 2021; 12:15067-15076. [PMID: 34909147 PMCID: PMC8612373 DOI: 10.1039/d1sc05089c] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 10/26/2021] [Indexed: 11/21/2022] Open
Abstract
We report the first planar hexacoordinate gallium (phGa) center in the global minimum of the GaBe6Au6 + cluster which has a star-like D 6h geometry with 1A1g electronic state, possessing a central gallium atom encompassed by a Be6 hexagon and each Be-Be edge is further capped by an Au atom. The electronic delocalization resulting in double aromaticity (both σ and π) provides electronic stability in the planar form of the GaBe6Au6 + cluster. The high kinetic stability of the title cluster is also understood by Born-Oppenheimer molecular dynamics simulations. The energy decomposition analysis in combination with the 'natural orbitals for chemical valence' theory reveals that the bonding in the GaBe6Au6 + cluster is best expressed as the doublet Ga atom with 4s24p⊥ 1 electronic configuration forming an electron-sharing π bond with the doublet Be6Au6 + moiety followed by Ga(s)→[Be6Au6 +] σ-backdonation and two sets of Ga(p‖)←[Be6Au6 +] σ-donations.
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Affiliation(s)
- Meng-Hui Wang
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University Changchun China
| | - Chen Chen
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University Changchun China
| | - Sudip Pan
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials, Nanjing Tech University Nanjing China
- Fachbereich Chemie, Philipps-Universität Marburg Hans-Meerwein-Strasse 4 35032 Marburg Germany
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University Changchun China
- Beijing National Laboratory for Molecular Sciences China
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Wang MH, Orozco-Ic M, Leyva-Parra L, Tiznado W, Barroso J, Ding YH, Cui ZH, Merino G. Planar Tetracoordinate Carbons in Allene-Type Structures. J Phys Chem A 2021; 125:3009-3014. [PMID: 33797250 DOI: 10.1021/acs.jpca.1c02002] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The exhaustive exploration of the potential energy surfaces of CE2M2 (E = Si-Pb; M = Li and Na) revealed seven global minima containing a planar tetracoordinate carbon (ptC). The design, based on a π-localization strategy, resulted in a ptC with two double bonds forming a linear or a bent allene-type E═C═E motif. The magnetic response of the bent E═C═E fragments support a σ-aromaticity. The bonding analysis indicated that the ptCs form C-E covalent bonds and C-M electrostatic interactions.
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Affiliation(s)
- Meng-Hui Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, P. R. China
| | - Mesías Orozco-Ic
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, km. 6 Antigua carretera a Progreso. Apdo. Postal 73, Cordemex, Mérida, Yucatán, México
| | - Luis Leyva-Parra
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, Santiago, Chile
| | - William Tiznado
- Computational and Theoretical Chemistry Group, Departamento de Ciencias Químicas, Facultad de Ciencias Exactas, Universidad Andres Bello, República 498, Santiago, Chile
| | - Jorge Barroso
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, km. 6 Antigua carretera a Progreso. Apdo. Postal 73, Cordemex, Mérida, Yucatán, México
| | - Yi-Hong Ding
- Key Laboratory of Carbon Materials of Zhejiang Province, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou 325035, P. R. China
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, P. R. China.,Beijing National Laboratory for Molecular Sciences, Beijing 100190, P. R. China
| | - Gabriel Merino
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida, km. 6 Antigua carretera a Progreso. Apdo. Postal 73, Cordemex, Mérida, Yucatán, México
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12
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Castillo-Toraya G, Orozco-Ic M, Dzib E, Zarate X, Ortíz-Chi F, Cui ZH, Barroso J, Merino G. Planar tetracoordinate fluorine atoms. Chem Sci 2021; 12:6699-6704. [PMID: 34040744 PMCID: PMC8132929 DOI: 10.1039/d1sc01325d] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Accepted: 04/07/2021] [Indexed: 11/21/2022] Open
Abstract
Among the list of planar tetracoordinate atoms, fluorine is missing. So far, there are no theoretical or experimental reports suggesting their existence. Herein, we introduce the first six combinations (FIn4 +, FTl4 +, FGaIn3 +, FIn2Tl2 +, FIn3Tl+, and FInTl3 +) whose global minima contain a planar tetracoordinate fluorine. The bonding analyses indicate that the interactions between the fluorine and the peripheral atoms are significantly electrostatic, which is also reflected in the electronic delocalization. As opposed to other planar tetracoordinate systems with carbon, nitrogen, or oxygen atoms, the fluorine in the ptFs does not act as a σ-acceptor, restraining any back-donation. On the other hand, σ-electrons show a diatropic response, which would characterize these clusters as σ-aromatic.
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Affiliation(s)
- Gabriela Castillo-Toraya
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida Mérida Yucatán México
| | - Mesías Orozco-Ic
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida Mérida Yucatán México
| | - Eugenia Dzib
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida Mérida Yucatán México
| | - Ximena Zarate
- Instituto de Ciencias Químicas Aplicadas, Facultad de Ingeniería, Universidad Autónoma de Chile Santiago Chile
| | - Filiberto Ortíz-Chi
- CONACYT-Universidad Juárez Autónoma de Tabasco, Centro de Investigación de Ciencia y Tecnología Aplicada de Tabasco Cunduacán 86690 Tabasco México
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University Changchun 130012 China
| | - Jorge Barroso
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida Mérida Yucatán México
| | - Gabriel Merino
- Departamento de Física Aplicada, Centro de Investigación y de Estudios Avanzados, Unidad Mérida Mérida Yucatán México
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Abstract
Dissociation pathways of the global minimum geometry of Si2C5H2 with a planar tetracoordinate carbon (ptC) atom, 2,7-disilatricyclo[4.1.0.01,3]hept-2,4,6-trien-2,7-diyl (1), have been theoretically investigated using density functional theory and coupled-cluster (CC) methods. Dissociation of Si-C bond connected to the ptC atom leads to the formation of 4,7-disilabicyclo[4.1.0]hept-1(6),4(5)-dien-2-yn-7-ylidene (4) through a single transition state. Dissociation of C-C bond connected to the ptC atom leads to an intermediate with two identical transition states and leads back to 1 itself. Simultaneous breaking of both Si-C and C-C bonds leads to an acyclic transition state, which forms an acyclic product, cis-1,7-disilahept-1,2,3,5,6-pentaen-1,7-diylidene (19). Overall, two different products, four transition states, and an intermediate have been identified at the B3LYP/6-311++G(2d,2p) level of theory. Intrinsic reaction coordinate calculations have also been done at the latter level to confirm the isomerization pathways. CC calculations have been done at the CCSD(T)/cc-pVTZ level of theory for all minima. Importantly, all reaction profiles for 1 are found be endothermic in Si2C5H2. These results are in stark contrast compared to the structurally similar and isovalent lowest-energy isomer of C7H2 with a ptC atom as the overall reaction profiles there have been found to be exothermic. The activation energies for Si-C, C-C, and Si-C/C-C breaking are found to be 30.51, 64.05, and 61.85 kcal mol−1, respectively. Thus, it is emphasized here that 1 is a kinetically stable molecule. However, it remains elusive in the laboratory to date. Therefore, energetic and spectroscopic parameters have been documented here, which may be of relevance to molecular spectroscopists in identifying this key anti-van’t-Hoff-Le Bel molecule.
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