1
|
Liu XB, Tiznado W, Cui LJ, Barroso J, Leyva-Parra L, Miao LH, Zhang HY, Pan S, Merino G, Cui ZH. Exploring the Use of "Honorary Transition Metals" To Push the Boundaries of Planar Hypercoordinate Alkaline-Earth Metals. J Am Chem Soc 2024; 146:16689-16697. [PMID: 38843775 PMCID: PMC11191695 DOI: 10.1021/jacs.4c03977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2024] [Revised: 05/24/2024] [Accepted: 05/24/2024] [Indexed: 06/23/2024]
Abstract
The quest for planar hypercoordinate atoms (phA) beyond six has predominantly focused on transition metals, with dodecacoordination being the highest reported thus far. Extending this bonding scenario to main-group elements, which typically lack d orbitals despite their larger atomic radius, has posed significant challenges. Intrigued by the potentiality of covalent bonding formation using the d orbitals of the heavier alkaline-earth metals (Ae = Ca, Sr, Ba), the so-called "honorary transition metals", we aim to push the boundaries of planar hypercoordination. By including rings formed by 12-15 atoms of boron-carbon and Ae centers, we propose a design scheme of 180 candidates with a phA. Further systematic screening, structural examination, and stability assessments identified 10 potential clusters with a planar hypercoordinate alkaline-earth metal (phAe) as the lowest-energy form. These unconventional structures embody planar dodeca-, trideca-, tetradeca-, and pentadecacoordinate atoms. Chemical bonding analyses reveal the important role of Ae d orbitals in facilitating covalent interactions between the central Ae atom and the surrounding boron-carbon rings, thereby establishing a new record for coordination numbers in the two-dimensional realm.
Collapse
Affiliation(s)
- Xin-bo Liu
- Institute
of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - William Tiznado
- Centro
de Química Teórica & Computacional (CQT&C),
Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, 8370146 Santiago de Chile, Chile
| | - Li-Juan Cui
- Institute
of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Jorge Barroso
- Department
of Chemistry, Clemson University, Clemson, South Carolina 29634, United States
| | - Luis Leyva-Parra
- Centro
de Química Teórica & Computacional (CQT&C),
Facultad de Ciencias Exactas, Departamento de Ciencias Químicas, Universidad Andrés Bello, Avenida República 275, 8370146 Santiago de Chile, Chile
| | - Lin-hong Miao
- Institute
of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - Hui-yu Zhang
- Institute
of Atomic and Molecular Physics, Jilin University, Changchun 130023, China
| | - 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, México
| | - 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
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Malhan AH, Thirumoorthy K. Global minimum and a heap of low-lying isomers with planar tetracoordinate carbon in the CAl 3MgH 2- system. Phys Chem Chem Phys 2024; 26:3804-3809. [PMID: 38240304 DOI: 10.1039/d3cp05841g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2024]
Abstract
A global minimum and a heap of low-lying isomers with planar tetracoordinate carbon (ptC) are identified in the CAl3MgH2- system by computational quantum chemical investigations. The nature of the chemical bonding in the global minimum ptC isomer is examined using the conceptual quantum chemical tools. The atoms in molecule (AIM) analysis reveals that the global minimum isomer possesses a ptC geometry. Additionally, the adaptive natural density partitioning (AdNDP), electron localization function (ELF), and nucleus-independent chemical shifts (NICS) analysis corroborate the presence of delocalization in the ptC isomer. The delocalization of electron density in the global minimum ptC isomer contributes to attaining structural stability. The results also suggest that the bridging hydrogen plays a crucial role in stabilizing the ptC system. Furthermore, the ab initio molecular dynamics study supports the structural stability of the ptC isomer.
Collapse
Affiliation(s)
- Abdul Hamid Malhan
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, Tamil Nadu, India.
| | - Krishnan Thirumoorthy
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore 632 014, Tamil Nadu, India.
| |
Collapse
|
4
|
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.
Collapse
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.
| |
Collapse
|
5
|
Fang L, Cao X, Cao Z. Chemical Bonding and Activity of Atomically Dispersed Silicon in Two- and Three-Dimensional Materials. J Phys Chem Lett 2023:11125-11133. [PMID: 38052049 DOI: 10.1021/acs.jpclett.3c02989] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
On the basis of the especially tunable electronic property of Si, several kinds of nanomaterials with atomically dispersed Si were constructed and characterized by extensive first-principles calculations and ab initio molecular dynamics (AIMD) simulations. The new-type Si(X≡Y)n wide-bandgap semiconductors featuring through-space d-π* hyperconjugation exhibit unique properties in photoelectric conversion, photoconductivity, structural mechanics, etc. The SiC8 siligraphene with the planar tetracoordinate Si (ptSi) has a high lithium-storage capacity and comparably facile surface migration behaviors of both Li and Li+, making it a promising anode material for high-performance Li-ion batteries. The atomically dispersed Si sites of 2D monolayer materials, such as ptSi and three- and four-coordinated Si atoms, generally exhibit remarkable catalytic activity toward CO2 activation with different electron mechanisms, resulting in different scaling relations between the activity and the p-band center. The computational findings enrich the understanding of structural and chemical properties of silicon and open up avenues for developing Si-based functional materials.
Collapse
Affiliation(s)
- Lei Fang
- College of Materials Science and Engineering, Huaqiao University, Xiamen 361021, China
| | - Xinrui Cao
- Department of Physics and Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient Devices, Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, Xiamen University, Xiamen 361005, China
| | - Zexing Cao
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, China
| |
Collapse
|
6
|
Jin B, Guan XL, Yan M, Wang YJ, Wu YB. Planar Hexacoordinate Beryllium: Covalent Bonding Between s-block Metals. Chemistry 2023; 29:e202302672. [PMID: 37695132 DOI: 10.1002/chem.202302672] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 09/08/2023] [Accepted: 09/11/2023] [Indexed: 09/12/2023]
Abstract
Achieving a planar hypercoordinate arrangement of s-block metals through covalent bonding with ligands is challenging due to the strong ionicity involved. Herein, we report the first case of a neutral binary global minimum containing a planar hexacoordinate beryllium atom. The central Be atom is coordinated by six active Be atoms, the latter in turn are enclosed by an equal number of more electronegative chlorine atoms in the periphery, forming a star-like phBe cluster (Be©Be6 Cl6 ). Importantly, the cluster exhibits dynamically stabilized stemming geometrically from the appropriate matching of metal-ligand size and electronically from adherence to the octet rule as well as possessing a 6σ/2π double aromaticity. Remarkably, energy decomposition analysis-natural orbitals for chemical valence (EDA-NOCV) analysis reveals a significant covalent interaction between the ligand and the central metal beryllium atoms, a fact further supported by a large Wiberg bond index. This cluster is a promising synthetic as its excellent electronic, dynamic and thermodynamic stability.
Collapse
Affiliation(s)
- Bo Jin
- Department of Chemistry, Xinzhou Normal University, Xinzhou, Shanxi, 034000, P. R. China
- Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, P. R. China
| | - Xiao-Ling Guan
- Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, P. R. China
| | - Miao Yan
- Department of Chemistry, Xinzhou Normal University, Xinzhou, Shanxi, 034000, P. R. China
| | - Ying-Jin Wang
- Department of Chemistry, Xinzhou Normal University, Xinzhou, Shanxi, 034000, P. R. China
| | - Yan-Bo Wu
- Institute of Molecular Science, Shanxi University, 92 Wucheng Road, Taiyuan, Shanxi, 030006, P. R. China
| |
Collapse
|
7
|
Handford RC, Tilley TD. A [CoSiH 2] Silylene Synthon Provides Modular Access to Homo- and Heterobimetallic [Co═Si═M] (M = Co, Fe) Silicide Complexes. J Am Chem Soc 2023; 145. [PMID: 37906296 PMCID: PMC10655182 DOI: 10.1021/jacs.3c07998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 10/04/2023] [Accepted: 10/05/2023] [Indexed: 11/02/2023]
Abstract
Base-stabilized [BP3iPr](H)2CoSiH2(DMAP) (1, [BP3iPr] = PhB(CH2PiPr2)3-; DMAP = 4-dimethylaminopyridine) is a rare instance of a synthon for the simplest "parent" silylene complex (LM═SiH2). Complex 1 was accessed in high yields via double Si-H bond activation in SiH4 by [BP3iPr]Co(DMAP), and in solution, it undergoes rapid exchange between bound and free DMAP by an associative mechanism (as determined by variable-temperature 1H NMR dynamic studies). The DMAP ligand of 1 is readily displaced by metal-based fragments that bind silicon and cleave the Si-H bonds of the SiH2 moiety to produce bimetallic [Co═Si═M] (M = Co, Fe) molecular silicides. Thus, treatment of 1 with 0.5 equiv of (LCoI)2(μ-N2) (L = a tripodal ligand) resulted in the spontaneous formation of [BP3iPr](H)2Co═Si═Co(H)2L (L = [BP2tBuPz], PhB(CH2PtBu2)2(pyrazolyl)- (3); Tp″, HB(3,5-diisopropylpyrazolyl)3- (4)) with the concomitant release of DMAP. The symmetrical silicide [BP3iPr](H)2Co═Si═Co(H)2[BP3iPr] (5) was prepared by treatment of a mixture of 1 and [BP3iPr]Co(DMAP) with 2 equiv of Ph3B, which in this case is required to sequester DMAP as the elimination product Ph3B-DMAP. A heterobimetallic silicide, [BP3iPr](H)2Co═Si═Fe(H)2[SiP3iPr] (7; [SiP3iPr] = PhSi(CH2PiPr2)3), was obtained via in situ KC8 reduction of [SiP3iPr]FeCl and subsequent addition of 1 and Ph3B. These transformations involving a metal-SiH2 derivative demonstrate a fundamentally new type of reactivity for silylene complexes and provide a unique synthetic method for construction of molecular silicide complexes.
Collapse
Affiliation(s)
- Rex C. Handford
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| | - T. Don Tilley
- Department of Chemistry, University of California, Berkeley, Berkeley, California 94720, United States
| |
Collapse
|
8
|
Wu CS, Su MD. Reactivity Analysis of the [2 + 2] Cycloaddition between Group-6 ≡ Group-14 Triple-Bonded Complexes and Acetylene: Insights from Theoretical Studies. Inorg Chem 2023; 62:16388-16400. [PMID: 37768726 DOI: 10.1021/acs.inorgchem.3c02020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/29/2023]
Abstract
Theoretical examinations of reactivity for the formal [2 + 2] cycloaddition of Me-C≡C-Ph to Group-6(G6)≡Group-14(G14) triple-bonded organometallic complexes have been carried out using the M06-2X-D3/def2-TZVP level of theory. Our theoretical findings suggest that Me-C≡C-Ph can undergo adduct formation with all G6≡Si complexes, resulting in the generation of four-membered ring structures. However, among the W≡Group-14 complex reactants, only W≡Si-based, W≡Ge-based, and W≡Sn-based organometallic molecules are capable of undergoing a [2 + 2] cycloaddition reaction with Me-C≡C-Ph. Based on energy decomposition analysis, our theoretical investigations demonstrate that the bonding mechanism in such [2 + 2] cycloaddition reactions involves the creation of two dative bonds between singlet fragments (the donor-acceptor model), as opposed to two electron-sharing bonds between triplet fragments. In addition, the examinations based on the activation strain model indicate that the activation barrier of the [2 + 2] cycloaddition reaction is predominantly governed by the geometric deformation energy of the two reactants (G6≡G14-Rea and Me-C≡C-Ph). Our research using the M06-2X method shows that the barrier heights of [2 + 2] cycloaddition reactions between Me-C≡C-Ph and G6≡Si-Rea are dependent on the geometric changes occurring in both fragments during the transition states, consistent with Hammond's postulate.
Collapse
Affiliation(s)
- Chi-Shiun Wu
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
| | - Ming-Der Su
- Department of Applied Chemistry, National Chiayi University, Chiayi 60004, Taiwan
- Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan
| |
Collapse
|
9
|
Grewelinger P, Wiesmeier T, Präsang C, Morgenstern B, Scheschkewitz D. Diboriranide σ-Complexes of d- and p-Block Metals. Angew Chem Int Ed Engl 2023; 62:e202308678. [PMID: 37522813 DOI: 10.1002/anie.202308678] [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: 06/20/2023] [Revised: 07/28/2023] [Accepted: 07/31/2023] [Indexed: 08/01/2023]
Abstract
Diboriranides are the smallest conceivable monoanionic aromatic cycles, yet only limited examples have been reported and their reactivity and complexation behavior remain completely unexplored. We report a straightforward synthesis of the first peraryl diboriranide c-(DurB)2 CPh- as its lithium salt in three steps via the corresponding non-classical diborirane from a readily available 1,2-dichlorodiborane(4) (Dur=2,3,5,6-tetramethylphenyl). With the preparation and complete characterization of representative complexes with tin, copper, gold and zinc, we demonstrate the strong preference of the diboriranide for σ-type coordination modes towards main group and transition metal centers under unperturbed retention of the three-membered B2 C-ring's 2e- π-system.
Collapse
Affiliation(s)
- Philipp Grewelinger
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Tim Wiesmeier
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Carsten Präsang
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| | - Bernd Morgenstern
- Service Center X-ray diffraction, Saarland University, 66123, Saarbrücken, Germany
| | - David Scheschkewitz
- Krupp-Chair for General and Inorganic Chemistry, Saarland University, 66123, Saarbrücken, Germany
| |
Collapse
|
10
|
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.
Collapse
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
| |
Collapse
|
11
|
Lee VY, Gapurenko OA. Pyramidanes: newcomers to the anti-van't Hoff-Le Bel family. Chem Commun (Camb) 2023; 59:10067-10086. [PMID: 37551825 DOI: 10.1039/d3cc02757k] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/09/2023]
Abstract
In this feature article, an overview of the chemistry of pyramidanes, as a novel class of main group element clusters, is given. A general introduction sets the scene, briefly presenting the non-classical pyramidal geometry of tetracoordinate carbon, as opposed to the classical tetrahedral configuration. Pyramidanes, as the simplest organic compounds possessing a pyramidal carbon atom, are then discussed from both computational and experimental viewpoints, to show the theoretical predictions on the stability and thus the feasibility of pyramidanes has finally culminated in the isolation of the first stable representatives of the pyramidane family featuring heavy main group elements at the apex of the square pyramid. Synthetic strategies towards pyramidanes, as well as their peculiar structural features, non-classical bonding situations, and specific reactivity, are presented and discussed in this review.
Collapse
Affiliation(s)
- Vladimir Ya Lee
- Department of Chemistry, Faculty of Pure and Applied Sciences, University of Tsukuba, Tsukuba 305-8571, Ibaraki, Japan.
| | - Olga A Gapurenko
- Institute of Physical and Organic Chemistry, Southern Federal University, Rostov on Don 344090, Russian Federation.
| |
Collapse
|
12
|
Yadav R, Janßen P, Schorpp M, Greb L. Calix[4]pyrrolato-germane-(thf) 2: Unlocking the Anti-van't Hoff-Le Bel Reactivity of Germanium(IV) by Ligand Dissociation. J Am Chem Soc 2023; 145:17746-17754. [PMID: 37549106 PMCID: PMC10436272 DOI: 10.1021/jacs.3c04424] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Indexed: 08/09/2023]
Abstract
Anti-van't Hoff-Le Bel configured p-block element species possess intrinsically high reactivity and are thus challenging to isolate. Consequently, numerous elements in this configuration, including square-planar germanium(IV), remain unexplored. Herein, we follow a concept to reach anti-van't Hoff-Le Bel reactivity by ligand dissociation from a rigid calix[4]pyrrole germane in its bis(thf) adduct. While the macrocyclic ligand assures square-planar coordination in the uncomplexed form, the labile thf donors provide robustness for isolation on a multigram scale. Unique properties of a low-lying acceptor orbital imparted to germanium(IV) can be verified, e.g., by isolating an elusive anionic hydrido germanate and exploiting it for challenging bond activations. Aldehydes, water, alcohol, and a CN triple bond are activated for the first time by germanium-ligand cooperativity. Unexpected behaviors against fluoride ion donors disclose critical interferences of a putative redox-coupled fluoride ion transfer during the experimental determination of Lewis acidity. Overall, we showcase how ligand lability grants access to the uncharted chemistry of anti-van't Hoff-Le Bel germanium(IV) and line up this element as a member in the emerging class of structurally constrained p-block elements.
Collapse
Affiliation(s)
| | | | | | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Heidelberg 69120, Germany
| |
Collapse
|
13
|
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.
Collapse
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
| |
Collapse
|
14
|
Liu X, Dai Y, Bao M, Wang W, Li Q, Liu C, Wang X, Su Y. A crystalline T-shaped planar group 14 anion. Chem Sci 2023; 14:5722-5727. [PMID: 37265721 PMCID: PMC10231432 DOI: 10.1039/d2sc07006e] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 04/11/2023] [Indexed: 06/03/2023] Open
Abstract
Isolable T-shaped planar pnictogen compounds R3Pn were reported more than three decades ago and have been attracting burgeoning interest in recent years; T-shaped planar group 14 anions, isoelectronic to R3Pn, however, are still unknown. Herein, we report the synthesis, full characterization, and reactivity of the first crystalline T-shaped planar group 14 anion 4 bearing a trinitrogen pincer ligand. DFT calculations indicate that the tricoordinate germanium center features both an unoccupied 4p orbital and two lone pairs of electrons. Its electron-rich nature allows for the nucleophilic attack on the methyl iodine giving methyl-substituted complex 5 and facile oxidation of the germanium center by elemental sulfur and selenium to furnish unpresented organic anions bearing terminal Ge[double bond, length as m-dash]Ch (Ch = S or Se) double bonds.
Collapse
Affiliation(s)
- Xiaona Liu
- College of Chemistry, Chemical Engineering and Materials Science, School of Radiation Medicine and Protection, Soochow University Suzhou 215123 China
| | - Yuyang Dai
- College of Chemistry, Chemical Engineering and Materials Science, School of Radiation Medicine and Protection, Soochow University Suzhou 215123 China
| | - Manling Bao
- College of Chemistry, Chemical Engineering and Materials Science, School of Radiation Medicine and Protection, Soochow University Suzhou 215123 China
| | - Wenjuan Wang
- College of Chemistry, Chemical Engineering and Materials Science, School of Radiation Medicine and Protection, Soochow University Suzhou 215123 China
| | - Qianli Li
- School of Chemistry and Chemical Engineering, Liaocheng University Liaocheng 252059 China
| | - Chunmeng Liu
- College of Chemistry, Chemical Engineering and Materials Science, School of Radiation Medicine and Protection, Soochow University Suzhou 215123 China
| | - Xinping Wang
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Yuanting Su
- College of Chemistry, Chemical Engineering and Materials Science, School of Radiation Medicine and Protection, Soochow University Suzhou 215123 China
- State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| |
Collapse
|
15
|
Maneri AH, Krishnamurty S, Joshi K. Understanding the Stability of an Unprecedented Si-Be Bond within Quantum Confinement. ACS OMEGA 2023; 8:14814-14822. [PMID: 37125089 PMCID: PMC10134223 DOI: 10.1021/acsomega.3c01133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 03/29/2023] [Indexed: 05/03/2023]
Abstract
As of today, the Si-Be bond remains underexplored in the literature, and therefore its anomalous behavior continues to be an unsolved puzzle to date. Therefore, the present study aims at evaluating the integrity of an unprecedented Si-Be bond within quantum confinement. To accomplish this, first-principles-based calculation are performed on Be-doped silicon clusters with atomic sizes 6, 7, and 10. Silicon clusters are sequentially doped with one, two, and three Be atoms, and their thermal response is registered in the temperature range of 200-1500 K, which discloses several research findings. During the course of the simulations, the clusters face various thermal events such as solid cluster phase, rapid structural metamorphosis, and fragmentation. Si-Be nanoalloy clusters are noted to be thermally stable at lower temperatures (200-700 K); however, they begins to disintegrate earlier at a temperature as low as 800 K. This lower stability is attributed to the weak nature of Si and Be heteroatomic interactions, which is corroborated from the structural and electronic property analysis of the doped clusters. In addition to this, the performance of Be-doped clusters at finite temperatures is also compared with the thermal response of two other popular systems, viz., C- and B-doped silicon clusters.
Collapse
Affiliation(s)
- Asma Harun Maneri
- Physical
and Materials Chemistry Division, CSIR-National
Chemical Laboratory (CSIR-NCL), Pune 411008, India
- Academy
of Scientific and Innovative Research (AcSIR), Gaziabad 201002, India
| | - Sailaja Krishnamurty
- Physical
and Materials Chemistry Division, CSIR-National
Chemical Laboratory (CSIR-NCL), Pune 411008, India
- Academy
of Scientific and Innovative Research (AcSIR), Gaziabad 201002, India
- ,
| | - Krati Joshi
- Physical
and Materials Chemistry Division, CSIR-National
Chemical Laboratory (CSIR-NCL), Pune 411008, India
- ,
| |
Collapse
|
16
|
Shan C, Dong S, Yao S, Zhu J, Driess M. Synthesis and Reactivity of an Anti-van't Hoff/Le Bel Compound with a Planar Tetracoordinate Silicon(II) Atom. J Am Chem Soc 2023; 145:7084-7089. [PMID: 36943751 DOI: 10.1021/jacs.3c00722] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
For a long time, planar tetracoordinate carbon (ptC) represented an exotic coordination mode in organic and organometallic chemistry, but it is now a useful synthetic building block. In contrast, realization of planar tetracoordinate silicon (ptSi), a heavier analogue of ptC, is still challenging. Herein we report the successful synthesis and unusual reactivity of the first ptSi species of divalent silicon present in 3, supported by the chelating bis(N-heterocyclic silylene)bipyridine ligand, 2,2'-{[(4-tBuPh)C(NtBu)]2SiNMe}2(C5N)2, 1]. The compound resulted from direct reaction of 1 with Idipp-SiI2 [Idipp = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene]. Alternatively, it can also be synthesized by a two-electron reduction of the corresponding Si(IV) precursor 2 with 2 molar equiv of KC10H8. Density functional theory calculations show that the lone pair at the ptSi(II) resides almost completely in its 3pz orbital, very different from known four-coordinate silylenes. Oxidative addition of MeI to the ptSi(II) atom affords the corresponding pentacoordinate Si(IV) compound 4, with the methyl group located in an apical position. Remarkably, the reaction of 2 with [CuOtBu] leads to the regeneration of the bis(silylene) arms via Si-Si bond scission and induces the Si(II) → Si(IV) oxidation of the central Si(II) atom and concomitant two-electron reduction of the bipyridine moiety to form the neutral bis(silylene)silyl Cu(I) complex 5.
Collapse
Affiliation(s)
- Changkai Shan
- Metalorganics and Inorganic Materials, Department of Chemistry, Technische Universität Berlin, Straße des 17, Juni 135, Sekr. C2, 10623 Berlin, Germany
| | - Shicheng Dong
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Shenglai Yao
- Metalorganics and Inorganic Materials, Department of Chemistry, Technische Universität Berlin, Straße des 17, Juni 135, Sekr. C2, 10623 Berlin, Germany
| | - Jun Zhu
- State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), College of Chemistry and Chemical Engineering, Xiamen University, 361005 Xiamen, China
| | - Matthias Driess
- Metalorganics and Inorganic Materials, Department of Chemistry, Technische Universität Berlin, Straße des 17, Juni 135, Sekr. C2, 10623 Berlin, Germany
| |
Collapse
|
17
|
Maurer LR, Engeser M. Group 6 germylidyne complexes in the gas phase by LIFDI and APCI mass spectrometry. EUROPEAN JOURNAL OF MASS SPECTROMETRY (CHICHESTER, ENGLAND) 2023; 29:44-57. [PMID: 36437806 DOI: 10.1177/14690667221137465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Although showing fascinating chemical properties and reactivity in solution, heavier tetrelylidyne complexes with M≡E triple bonds have not been studied in the gas phase before due to their high sensitivity towards air and moisture. We selected four group 6 germylidyne complexes, [Cp(PMe3)2M≡GeArMes] (M = Mo (1-Mo), W (1-W), ArMes = 2,6-dimesitylphenyl) and [Tp'(CO)2M≡GeArMes] (M = Mo (2-Mo), W (2-W), Tp' = κ3-N,N',N''-hydridotris(3,5-dimethylpyrazolyl) borate), for a mass-spectrometric study. Liquid Injection Field Desorption Ionization (LIFDI) proved to be a well-suited technique to ionize these sensitive compounds as the spectra show the molecular ions as radical cations and only minor traces of fragmentation or degradation products. In addition, Atmospheric Pressure Chemical Ionization (APCI) connected to a high-resolving tandem mass spectrometer allowed us to study the gas-phase fragmentation behaviour of these compounds. The fragmentation patterns not only comprise the expected losses of phosphane or carbonyl ligands, respectively, but also indicate C-H bond activation by the electron-deficient metal centre. An enhanced reactivity of the tungsten species is visible in a preferred methyl abstraction in the phosphane complex 1-W compared to 1-Mo. Although degradation in solution before ionization obviously can destroy the M≡Ge triple bond, the cleavage of the M≡Ge bond upon gas-phase activation is not observed for the Mo species and only as a minor pathway for the W compounds, highlighting the high bonding energy between metal and tetrel.
Collapse
|
18
|
Li HX, Wang MH, Li Q, Cui ZH. Two-dimensional Be 2Al and Be 2Ga monolayer: anti-van't Hoff/Le Bel planar hexacoordinate bonding and superconductivity. Phys Chem Chem Phys 2023; 25:1105-1113. [PMID: 36514964 DOI: 10.1039/d2cp04595h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Because of the electron deficiency of boron, a triangular network with planar hexacoordination is the most common structural and bonding property for isolated boron clusters and two-dimensional (2D) boron sheets. However, this network is a rule-breaking structure and bonding case for all other main-group elements. Herein, the Be2M (M = Al and Ga) 2D monolayer with P6/mmm space group was found to be the lowest-energy structure with planar hexacoordinate Be/Al/Ga motifs. More interestingly, Be2Al and Be2Ga were observed to be intrinsic phonon-mediated superconductors with a superconducting critical temperature (Tc) of 5.9 and 3.6 K, respectively, where compressive strain could further enhance their Tc. The high thermochemical and kinetic stability of Be2M make a promising candidate for experimental realization, considering its high cohesive energy, absence of soft phonon modes, and good resistance to high temperature. Moreover, the feasibility of directly growing Be2M on the electride Ca2N substrate was further demonstrated, where its intriguing electronic and superconducting properties were well maintained in comparison with the freestanding monolayer. The Be2M monolayer with rule-breaking planar hexacoordinate motifs firmly pushes the ultimate connection of the "anti-van't Hoff/Le Bel" structure with promising physical properties.
Collapse
Affiliation(s)
- Hai-Xia Li
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
| | - Meng-Hui Wang
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130023, China.
| | - Quan Li
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130023, People's Republic of China
| | - 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
| |
Collapse
|
19
|
Zhao LQ, Guo JC, Zhai HJ. Ternary 14-electron XB 2Be 2 (X = Si, Ge, Sn, Pb) clusters: a planar tetracoordinate silicon (ptSi) system and its ptGe/Sn/Pb congeners. Phys Chem Chem Phys 2022; 24:7068-7076. [PMID: 35258052 DOI: 10.1039/d1cp05226h] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A class of ternary 14-electron clusters, XB2Be2 (X = Si, Ge, Sn, Pb), have been computationally predicted with a planar tetracoordinate silicon (ptSi) unit, as well as its heavier ptGe/Sn/Pb congeners. These pentaatomic ptSi/Ge/Sn/Pb species are established as global-minimum structures via computer global searches, followed by electronic structure calculations at the PBE0-D3, B3LYP-D3, and single-point CCSD(T) levels. Molecular dynamics simulations indicate that they are also kinetically stable against isomerization or decomposition. Chemical bonding analyses show that the clusters have double 2π/2σ aromaticity. The latter concept underlies the stability of ptSi/Ge/Sn/Pb clusters, overriding the 14-electron count or its variants, such as the 18-electron rule. No sp3 hybridization occurs in these species, which naturally explains why they are ptSi/Ge/Sn/Pb (rather than traditional tetrahedral) systems.
Collapse
Affiliation(s)
- 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.
| |
Collapse
|
20
|
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.
Collapse
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
| |
Collapse
|
21
|
Wang MH, Cui ZH, Wang S, Li Q, Zhao J, Chen Z. Two-dimensional Be2Au Monolayer with Planar Hexacoordinate s-Block Metal Atoms: A Superconducting Global Minimum Dirac Material with Two Perfect Dirac Node-Loops. Chem Sci 2022; 13:11099-11109. [PMID: 36320472 PMCID: PMC9517706 DOI: 10.1039/d2sc03614b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 08/26/2022] [Indexed: 11/21/2022] Open
Abstract
Using a starlike Be6Au7− cluster as a building block and following the bottom-up strategy, an intriguing two-dimensional (2D) binary s-block metal Be2Au monolayer with a P6/mmm space group was theoretically designed. Both the Be6Au7− cluster and the 2D monolayer are global minima featuring rule-breaking planar hexacoordinate motifs (anti-van't Hoff/Le Bel arrangement), and their high stabilities are attributed to good electron delocalization and electronic-stabilization-induced steric force. Strikingly, the Be2Au monolayer is a rare Dirac material with two perfect Dirac node-loops in the band structure and is a phonon-mediated superconductor with a critical temperature of 4.0 K. The critical temperature can be enhanced up to 11.0 K by applying compressive strain at only 1.6%. This study not only identifies a new binary s-block metal 2D material, namely Be2Au, which features planar hexacoordination, and a candidate superconducting material for further explorations, but also provides a new strategy to construct 2D materials with novel chemical bonding. A topological superconductor, named Be2Au monolayer, containing planar hexacoordinate s-block metal (Be and Au) atoms was theoretically designed by rationally assembling related clusters.![]()
Collapse
Affiliation(s)
- Meng-Hui Wang
- Institute of Atomic and Molecular Physic, Jilin University Changchun 130012 China
| | - Zhong-Hua Cui
- Institute of Atomic and Molecular Physic, Jilin University Changchun 130012 China
- Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University Changchun 130012 China
| | - Sheng Wang
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University Changchun 130023 People's Republic of China
| | - Quan Li
- State Key Laboratory of Superhard Materials, College of Physics, Jilin University Changchun 130023 People's Republic of China
| | - Jijun Zhao
- Key Laboratory of Materials Modification by Laser, Ion and Electron Beams (Dalian University of Technology), Ministry of Education Dalian 116024 China
| | - Zhongfang Chen
- Department of Chemistry, University of Puerto Rico San Juan PR 00931 USA
| |
Collapse
|
22
|
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.
Collapse
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
| |
Collapse
|
23
|
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.
Collapse
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
| |
Collapse
|
24
|
Abstract
Carbide complexes remain a rare class of molecules. Their paucity does not reflect exceptional instability but is rather due to the generally narrow scope of synthetic procedures for constructing carbide complexes. The preparation of carbide complexes typically revolves around generating LnM-CEx fragments, followed by cleavage of the C-E bonds of the coordinated carbon-based ligands (the alternative being direct C atom transfer). Prime examples involve deoxygenation of carbonyl ligands and deprotonation of methyl ligands, but several other p-block fragments can be cleaved off to afford carbide ligands. This Review outlines synthetic strategies toward terminal carbide complexes, bridging carbide complexes, as well as carbide-carbonyl cluster complexes. It then surveys the reactivity of carbide complexes, covering stoichiometric reactions where the carbide ligands act as C1 reagents, engage in cross-coupling reactions, and enact Fischer-Tropsch-like chemistry; in addition, we discuss carbide complexes in the context of catalysis. Finally, we examine spectroscopic features of carbide complexes, which helps to establish the presence of the carbide functionality and address its electronic structure.
Collapse
Affiliation(s)
- Anders Reinholdt
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| | - Jesper Bendix
- Department of Chemistry, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen, Denmark
| |
Collapse
|
25
|
Abstract
Six-valence-electron planar pentacoordinate beryllium (ppBe) is explored herein as a global minimum, which is only constructed by s-block metals in BeM5+ (M = Cu, Ag, Au). The bonding in ppBe can be regarded as the excited-stated Be with a 2px12py1 electronic configuration, forming electron sharing with doublet M5+ motifs followed by two sets of Be(p∥) → [M5+] σ donations and one Be(s) ← [M5+] σ back-donation. Thus, the σ aromaticity originating from three delocalized σ orbitals gives rise to the whole stability of the high D5h-symmetry ppBe and strongly enriches s-block planar hypercoordinate bonding.
Collapse
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 130012, China
| | - Yu-Qian Liu
- Institute of Atomic and Molecular Physics, Key Laboratory of Physics and Technology for Advanced Batteries (Ministry of Education), Jilin University, Changchun 130012, 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 130012, China
| |
Collapse
|
26
|
Abstract
We have explored the chemical space of BAl4Mg−/0/+ for the first time and theoretically characterized several isomers with interesting bonding patterns. We have used chemical intuition and a cluster building method based on the tabu-search algorithm implemented in the Python program for aggregation and reaction (PyAR) to obtain the maximum number of possible stationary points. The global minimum geometries for the anion (1a) and cation (1c) contain a planar tetracoordinate boron (ptB) atom, whereas the global minimum geometry for the neutral (1n) exhibits a planar pentacoordinate boron (ppB) atom. The low-lying isomers of the anion (2a) and cation (3c) also contain a ppB atom. The low-lying isomer of the neutral (2n) exhibits a ptB atom. Ab initio molecular dynamics simulations carried out at 298 K for 2000 fs suggest that all isomers are kinetically stable, except the cation 3c. Simulations carried out at low temperatures (100 and 200 K) for 2000 fs predict that even 3c is kinetically stable, which contains a ppB atom. Various bonding analyses (NBO, AdNDP, AIM, etc.) are carried out for these six different geometries of BAl4Mg−/0/+ to understand the bonding patterns. Based on these results, we conclude that ptB/ppB scenarios are prevalent in these systems. Compared to the carbon counter-part, CAl4Mg−, here the anion (BAl4Mg−) obeys the 18 valence electron rule, as B has one electron fewer than C. However, the neutral and cation species break the rule with 17 and 16 valence electrons, respectively. The electron affinity (EA) of BAl4Mg is slightly higher (2.15 eV) than the electron affinity of CAl4Mg (2.05 eV). Based on the EA value, it is believed that these molecules can be identified in the gas phase. All the ptB/ppB isomers exhibit π/σ double aromaticity. Energy decomposition analysis predicts that the interaction between BAl4−/0/+ and Mg is ionic in all these six systems.
Collapse
|
27
|
Stereomutation in Tetracoordinate Centers via Stabilization of Planar Tetracoordinated Systems. ATOMS 2021. [DOI: 10.3390/atoms9040079] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The quest for stabilizing planar forms of tetracoordinate carbon started five decades ago and intends to achieve interconversion between [R]- and [S]-stereoisomers without breaking covalent bonds. Several strategies are successful in making the planar tetracoordinate form a minimum on its potential energy surface. However, the first examples of systems where stereomutation is possible were reported only recently. In this study, the possibility of neutral and dications of simple hydrocarbons (cyclopentane, cyclopentene, spiropentane, and spiropentadiene) and their counterparts with the central carbon atom replaced by elements from groups 13, 14, and 15 are explored using ab initio MP2 calculations. The energy difference between the tetrahedral and planar forms decreases from row II to row III or IV substituents. Additionally, aromaticity involving the delocalization of the lone pair on the central atom appears to help in further stabilizing the planar form compared to the tetrahedral form, especially for the row II substituents. We identified 11 systems where the tetrahedral state is a minimum on the potential energy surface, and the planar form is a transition state corresponding to stereomutation. Interestingly, the planar structures of three systems were found to be minimum, and the corresponding tetrahedral states were transition states. The energy profiles corresponding to such transitions involving both planar and tetrahedral states without the breaking of covalent bonds were examined. The systems showcased in this study and research in this direction are expected to realize molecules that experimentally exhibit stereomutation.
Collapse
|
28
|
Ebner F, Greb L. An isolable, crystalline complex of square-planar silicon(IV). Chem 2021; 7:2151-2159. [PMID: 34435162 PMCID: PMC8367297 DOI: 10.1016/j.chempr.2021.05.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Revised: 03/01/2021] [Accepted: 05/04/2021] [Indexed: 12/16/2022]
Abstract
The structure and reactivity of silicon(IV), the second most abundant element in our Earth's crust, is determined by its invariant tetrahedral coordination geometry. Silicon(IV) with a square-planar configuration (ptSi IV ) represents a transition state. Quantum theory supported the feasibility of stabilizing ptSi IV by structural constraint, but its isolation has not been achieved yet. Here, we present the synthesis and full characterization of the first square-planar coordinated silicon(IV). The planarity provokes an extremely low-lying unoccupied molecular orbital that induces unusual silicon redox chemistry and CH-agostic interactions. The small separation of the frontier molecular orbitals enables visible-light ligand-element charge transfer and bond-activation reactivity. Previously, such characteristics have been reserved for d-block metals or low-valent p-block elements. Planarization transfers them, for the first time, to a p-block element in the normal valence state.
Collapse
Affiliation(s)
- Fabian Ebner
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120 Heidelberg, Germany
| | - Lutz Greb
- Anorganisch-Chemisches Institut, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 275, 69120 Heidelberg, Germany
| |
Collapse
|
29
|
Abstract
Isomers of CAl4Mg and CAl4Mg− have been theoretically characterized for the first time. The most stable isomer for both the neutral and anion contain a planar tetracoordinate carbon (ptC) atom. Unlike the isovalent CAl4Be case, which contains a planar pentacoordinate carbon atom as the global minimum geometry, replacing beryllium with magnesium makes the ptC isomer the global minimum due to increased ionic radii of magnesium. However, it is relatively easier to conduct experimental studies for CAl4Mg0/− as beryllium is toxic. While the neutral molecule containing the ptC atom follows the 18 valence electron rule, the anion breaks the rule with 19 valence electrons. The electron affinity of CAl4Mg is in the range of 1.96–2.05 eV. Both the global minima exhibit π/σ double aromaticity. Ab initio molecular dynamics simulations were carried out for both the global minima at 298 K for 10 ps to confirm their kinetic stability.
Collapse
|
30
|
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.
Collapse
|