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Jin B, Yan M, Feng LY, Miao CQ, Wang YJ. CBe 2 H 5 - : Unprecedented 2σ/2π Double Aromaticity and Dynamic Structural Fluxionality in a Planar Tetracoordinate Carbon Cluster. Chemistry 2024:e202304134. [PMID: 38205620 DOI: 10.1002/chem.202304134] [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: 12/11/2023] [Revised: 01/10/2024] [Accepted: 01/11/2024] [Indexed: 01/12/2024]
Abstract
A 14-electron ternary anionic CBe2 H5 - cluster containing a planar tetracoordinate carbon (ptC) atom is designed herein. Remarkably, it can be stabilized by only two beryllium atoms with both π-acceptor/σ-donor properties and two hydrogen atoms, which means that the conversion from planar methane (transition state) to ptC species (global minimum) requires the substitution of only two hydrogen atoms. Moreover, two ligand H atoms exhibit alternate rotation, giving rise to interesting dynamic fluxionality in this cluster. The electronic structure analysis reveals the flexible bonding positions of ligand H atoms due to C-H localized bonds, highlighting the rotational fluxionality in the cluster, and two CBe2 3c-2e delocalized bonds endow its rare 2σ/2π double aromaticity. Unprecedentedly, the fluxional process exhibits a conversion in the type of bonding (σ bond↔π bond), which is an uncommon fluxional mechanism. The cluster can be seen as an attempt to apply planar hypercoordinate carbon species to molecular motors.
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Affiliation(s)
- Bo Jin
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi, 034000, People's Republic of China
| | - Miao Yan
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi, 034000, People's Republic of China
| | - Lin-Yan Feng
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi, 034000, People's Republic of China
| | - Chang-Qing Miao
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi, 034000, People's Republic of China
| | - Ying-Jin Wang
- Department of Chemistry, Xinzhou Normal University, 1 East Dunqi Street, Xinzhou, Shanxi, 034000, People's Republic of China
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Jia XD, Du ZW. 18-valence-electron rule lighted planar tetracoordinate carbon and nitrogen: the global energy minima of CAl 4Zn and NAl 4Zn . Phys Chem Chem Phys 2023; 25:4211-4215. [PMID: 36655923 DOI: 10.1039/d2cp04743h] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The exploration of planar hypercoordinate carbon (phC) is challenging and significant. It is often puzzling to chemists whether the designed phC species should satisfy the 18-valence-electron rule, an authoritative rule in the phC field. In this study, we introduced a zinc atom into the extremely unstable 16-valence-electron planar tetracoordinate carbon (ptC) species CAl4 and its isoelectronic structure NAl4+ with a planar tetracoordinate nitrogen (ptN), and designed the 18-valence-electron CAl4Zn and NAl4Zn+ possessing a ptC and ptN, respectively. The thermodynamic results indicate that the ptC/N species CAl4Zn and NAl4Zn+ are the global energy minima, and also showed that the 18-valence-electron rule is more appropriate in designing ptC/N species having the CAl4 and NAl4+ skeletons, compared with the 16-valence-electron rule. Simultaneously, the BOMD simulations found that CAl4Zn is dynamically stable. Although NAl4Zn+ was isomerized at 298 and 500 K, it is dynamically viable. The excellent stability may be explained by the perfect electronic structure. First, the HOMO-LUMO gaps became much wider after the introduction of the Zn atom. Second, AdNDP analysis indicated that the introduction of the Zn atom promoted the formation of peripheral Al-Al and Al-Zn covalent bonds, providing a stable and comfortable bonding environment for ptC/N. In addition, the σ and π double aromaticity further stabilized the ptC/N species. Hence, as dynamic global energy minima display σ and π double aromaticity, the ptC/N species CAl4Zn and NAl4Zn+ are promising in gas phase generation.
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Affiliation(s)
- Xiu-Dong Jia
- Institute of Molecular Science, Shanxi University, Taiyuan, 030006, People's Republic of China.
| | - Zhi-Wei Du
- School of Chemistry and Chemical Engineering, Shanxi University, Taiyuan, 030006, People's Republic of China
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Structure and Bonding in Planar Hypercoordinate Carbon Compounds. CHEMISTRY 2022. [DOI: 10.3390/chemistry4040113] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The term hypercoordination refers to the extent of the coordination of an element by its normal value. In the hypercoordination sphere, the element can achieve planar and/or non-planar molecular shape. Hence, planar hypercoordinate carbon species violate two structural rules: (i) The highest coordination number of carbon is four and (ii) the tetrahedral orientation by the connected elements and/or groups. The unusual planar orientations are mostly stabilized by the electronic interactions of the central atom with the surrounding ligands. In this review article, we will talk about the current progress in the theoretical prediction of viable planar hypercoordinate carbon compounds. Primary knowledge of the planar hypercoordinate chemistry will lead to its forthcoming expansion. Experimental and theoretical interests in planar tetracoordinate carbon (ptC), planar pentacoordinate carbon (ppC), and planar hexacoordinate carbon (phC) are continued. The proposed electronic and mechanical strategies are helpful for the designing of the ptC compounds. Moreover, the 18-valence electron rule can guide the design of new ptC clusters computationally as well as experimentally. However, the counting of 18-valence electrons is not a requisite condition to contain a ptC in a cluster. Furthermore, this ptC idea is expanded to the probability of a greater coordination number of carbon in planar orientations. Unfortunately, until now, there are no such logical approaches to designing ppC, phC, or higher-coordinate carbon molecules/ions. There exist a few global minimum structures of phC clusters identified computationally, but none have been detected experimentally. All planar hypercoordinate carbon species in the global minima may be feasible in the gas phase.
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Das P, Khatun M, Anoop A, Chattaraj PK. CSi nGe 4-n2+ ( n = 1-3): prospective systems containing planar tetracoordinate carbon (ptC). Phys Chem Chem Phys 2022; 24:16701-16711. [PMID: 35770562 DOI: 10.1039/d2cp01494g] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Density functional theory (DFT) based calculations have been carried out to explore the potential energy surface (PES) of CSinGe4-n2+/+/0 (n = 1-3) systems. The global minimum structures in the di-cationic states (1a, 1b, and 1c) contain a planar tetracoordinate carbon (ptC). For the CSi2Ge22+ system, the second stable isomer (2b) also contains a ptC with 0.67 kcal mol-1 higher energy than that of the 1b ptC isomer. The global minima of the neutral and mono-cationic states of the designed systems are not planar. The 1a, 1b, and 1c structures follow the 18 valence electron rule. The relative energies of the low-lying isomers of CSiGe32+, CSi2Ge22+, and CSi3Ge2+ systems with respect to the global minima were calculated using the CCSD(T)/aug-cc-pVTZ method. Ab initio molecular dynamics simulations for 50 ps time indicate that all the global minimum structures (1a, 1b, and 1c) are kinetically stable at 300 K and 500 K temperatures. The natural bond orbital (NBO) analysis suggests strong σ-acceptance of the ptC from the four surrounding atoms and simultaneously π-donation occurs from the ptC center. The nucleus independent chemical shift (NICS) showed σ/π-dual aromaticity. We hope that the designed di-cationic systems may be viable in the gas phase.
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Affiliation(s)
- Prasenjit Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Maya Khatun
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Anakuthil Anoop
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
| | - Pratim Kumar Chattaraj
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur 721302, India.
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Das P, Chattaraj PK. CSiGaAl 2 -/0 and CGeGaAl 2 -/0 having planar tetracoordinate carbon atoms in their global minimum energy structures. J Comput Chem 2022; 43:894-905. [PMID: 35322887 DOI: 10.1002/jcc.26845] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/20/2022] [Accepted: 03/09/2022] [Indexed: 11/12/2022]
Abstract
Density functional theory (DFT) is used to explore the structure, stability, and bonding in CSiGaAl2 -/0 and CGeGaAl2 -/0 systems having planar tetracoordinate carbon (ptC). The neutral systems have 17 valence electrons and the mono-anionic systems have 18 valence electrons. The ab initio molecular dynamics simulations for 2000 fs time at two different temperatures (300 and 500 K) supported the kinetic stability of the systems. From the natural bond orbital (NBO) analysis it is shown that there is a strong electron donation from the ligand atoms to the ptC atom. We have used Li+ ion for the neutralization of the mono-anionic systems and more interestingly it does not disrupt the planar structure. The most preferable site for binding of Li+ ion is along the AlAl bond in both of the mono-anionic systems. All the systems in this work have both σ and π aromaticity which is predicted from the computations of nucleus independent chemical shift (NICS). Although the anionic species obey the 18 valence electronic rule, the neutral systems break the rule with 17 valence electrons. However, both sets of systems are stable in the planar form. The bonding analysis of the systems includes molecular orbital, adaptive natural density partitioning (AdNDP), quantum theory of atoms in molecules (QTAIM), electron localization function (ELF) basin, and aromaticity analyses. The energy decomposition analysis (EDA) determines the interaction of Li+ ion with CSiGaAl2 - and CGeGaAl2 - in Li@SiGaAl2 and Li@GeGaAl2 , respectively.
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Affiliation(s)
- Prasenjit Das
- Department of Chemistry, Indian Institute of Technology Kharagpur, Kharagpur, India
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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.
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Thirumoorthy K, Cooksy AL, Thimmakondu VS. Si 2C 5H 2 isomers - search algorithms versus chemical intuition. Phys Chem Chem Phys 2020; 22:5865-5872. [PMID: 32108184 DOI: 10.1039/c9cp06145b] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The pros and cons of using search algorithms alone in identifying new geometries have been discussed by using the Si2C5H2 elemental composition as an example. Within 30 kcal mol-1 at the CCSD(T)/def2-TZVP//PBE0/def2-TZVP level of theory, the coalescence kick and cuckoo methods postulate merely four isomers (1, 3, 6, and 7) for Si2C5H2 (O. Yañez et. al., Chem. Commun., 2017, 53, 12112). On the contrary, chemical intuition yields fourteen (2, 4, 5, and 8-18) new isomers within the same energy range at the B3LYP/6-311++G(2d,2p) level of theory. Based on the relative energies of the first eleven isomers of Si2C5H2 (1, C2v, 0.00; 2, Cs, 21.39; 3, Cs, 21.95; 4, Cs, 22.76; 5, Cs, 24.74; 6, Cs, 25.34; 7, Cs, 25.64; 8, Cs, 25.79; 9, Cs, 27.20; 10, C2v, 28.59; and 11, C2v, 29.16 kcal mol-1) calculated at the CCSD(T)/cc-pVTZ level of theory, it is evident that the search algorithms had missed at least seven isomers in the same energy range. The relative energy gaps of isomers 12-18 fall in the range of 30-40 kcal mol-1 at the latter level of theory. Consequentially, this scenario triggers a speculation going forward with search algorithms alone in the search of all new isomers. While one cannot underestimate the power of these algorithms, the role of chemical intuition may not be completely neglected. Retrospectively, the fourteen new isomers found by chemical intuition may help in writing better search algorithms. All eighteen isomers - including the most stable isomer with a planar tetracoordinate carbon atom 1- remain elusive in the laboratory to date. Thus, structural and spectroscopic parameters have been presented here, which may possibly aid the future experimental studies.
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Affiliation(s)
- Krishnan Thirumoorthy
- Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore - 632 014, Tamil Nadu, India
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Job N, Karton A, Thirumoorthy K, Cooksy AL, Thimmakondu VS. Theoretical Studies of SiC 4H 2 Isomers Delineate Three Low-Lying Silylidenes Are Missing in the Laboratory. J Phys Chem A 2020; 124:987-1002. [PMID: 31904236 DOI: 10.1021/acs.jpca.9b11742] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Eleven isomers of SiC4H2 lying within 50 kcal mol-1 have been theoretically investigated using density functional theory and high-level coupled-cluster methods. Among them, four isomers, 1-ethynyl-3-silacycloprop-1(2)-en-3-ylidene (1), diethynylsilylidene (2), 1-sila-1,2,3,4-pentatetraenylidene (4), and 1,3-butadiynylsilylidene (5), have already been identified in the laboratory. The current investigation reports three low-lying (<1 eV) silylidenes [2-methylenesilabicyclo[1.1.0]but-1(3)-en-4-ylidene (3), 4-sila-2-methylenebicyclo[1.1.0]but-1(3)-en-4-ylidene (6), and 3-ethynyl-1-silapropadienylidene (7)] and three high-lying (>1 eV) silylidenes [2-sila-(didehydrovinylidene)cyclopropene (8), an isomer with a planar tetracoordinate carbon (ptC) atom (10), and 1-ethynyl-1-silapropadienylidene (11)], which remain elusive in the laboratory to date. Isomer 9 also contains a ptC atom, which turned out to be a transition state at all levels. Though all isomers are polar (μ ≠ 0), rotational spectrum is available only for 4. Using matrix isolation, three isomers (1, 2, and 5) have been trapped in the laboratory at 10 K. Considering the astrochemical relevance of silicon-carbide clusters in the interstellar medium, the current theoretical data demand new molecular spectroscopic studies on SiC4H2. Surprisingly, unlike the isovalent C5H2 isomers, where the bent carbenes are yet to be identified in the laboratory, the bent silylidenes (2 and 5) have been trapped in the case of SiC4H2. In both the cases, molecules with transannular C-C and/or Si-C bonds remain elusive, though they lie in the low-lying region. Using suitable precursors, whether these peculiar geometries (especially 3 and 6) would be identified or not in the laboratory needs to be addressed by molecular spectroscopists. The present investigation documents structural and spectroscopic information of SiC4H2 isomers, which may compliment future molecular spectroscopic observations including radioastronomical searches.
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Affiliation(s)
- Nisha Job
- Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore 632014 , Tamil Nadu , India
| | - Amir Karton
- School of Molecular Sciences , The University of Western Australia , Perth , Western Australia 6009 , Australia
| | - Krishnan Thirumoorthy
- Department of Chemistry, School of Advanced Sciences , Vellore Institute of Technology , Vellore 632014 , Tamil Nadu , India
| | - Andrew L Cooksy
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
| | - Venkatesan S Thimmakondu
- Department of Chemistry and Biochemistry , San Diego State University , San Diego , California 92182-1030 , United States
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Feng W, Zhu C, Liu X, Zhang M, Geng Y, Zhao L, Su Z. A BPt4S4 cluster: a planar tetracoordinate boron system with three charges all at their global energy minima. NEW J CHEM 2020. [DOI: 10.1039/c9nj05456a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The monoanion state of BPt4S4− possesses the lowest energy among the three oxidation states with planar tetracoordinate boron.
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Affiliation(s)
- Wei Feng
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
| | - Changyan Zhu
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
| | - Xingman Liu
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
| | - Min Zhang
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
| | - Yun Geng
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
| | - Liang Zhao
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
| | - Zhongmin Su
- Institute of Functional Material Chemistry
- Faculty of Chemistry & National & Local United Engineering Laboratory for Power Battery
- Northeast Normal University
- Changchun 130024
- P. R. China
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Guo JC, Feng LY, Zhai HJ. Planar tetracoordinate carbon molecules with 14 valence electrons: examples of CBe4Mnn−2 (M = Li, Au; n = 1–3) clusters. NEW J CHEM 2020. [DOI: 10.1039/d0nj03944f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Planar tetracoordinate carbon species are viable with 14 valence electrons, which violate the 18-electron rule. Chemical bonding around the C center is governed by double 2π/6σ aromaticity.
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Affiliation(s)
- Jin-Chang Guo
- Nanocluster Laboratory
- Institute of Molecular Science
- Shanxi University
- Taiyuan 030006
- China
| | - Lin-Yan Feng
- 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
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Wu XF, Cheng YX, Guo JC. CLiAl 2E and CLi 2AlE (E = P, As, Sb, Bi): Planar Tetracoordinate Carbon Clusters with 16 and 14 Valence Electrons. ACS OMEGA 2019; 4:21311-21318. [PMID: 31867525 PMCID: PMC6921633 DOI: 10.1021/acsomega.9b02869] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 11/15/2019] [Indexed: 06/10/2023]
Abstract
The strategy to remove the lone pairs of ligands combined with the bonding similarity between Li and Al have been utilized to design new planar tetracoordinate carbon (ptC) species C 2v CLiAl2E and CLi2AlE based on ptC global minima CAl3E (E = P, As, Sb, Bi) clusters. The explorations of potential energy surfaces and high-level CCSD(T) calculations indicate that these planar tetracoordinate carbon (ptC) species with 16 and 14 valence electrons (ve) are the global minima except for CLiAl2P. Bonding analyses reveal that there is one π and three σ bonds between C and ligands, one delocalized σ bond between the peripheral ligands, and three/two lone pairs for CLiAl2E and CLi2AlE (E = P, As, Sb, Bi). Especially, the C=E double bonds are crucial for the stabilities of these ptC clusters. The ptC core is governed by 2π + 6σ bonding, which conforms to the 8-electron counting. Born-Oppenheimer molecular dynamics (BOMD) simulations reveal that CLiAl2E and CLi2AlE (E = P, As, Sb, Bi) clusters are robust against isomerization and decomposition. The results obtained in this work complete the series of ptC CLi n Al3-n E (E = P, As, Sb, Bi; n = 0-3) systems and 18ve, 16ve, 14ve, and 12ve counting.
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Affiliation(s)
- Xiao-Feng Wu
- The
School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, Shanxi, China
| | - Ya-Xuan Cheng
- Department
of Chemistry, Xinzhou Teachers’ University, Xinzhou 034000, Shanxi, China
| | - Jin-Chang Guo
- The
School of Chemistry and Material Science, Shanxi Normal University, Linfen 041004, Shanxi, China
- Department
of Chemistry, Xinzhou Teachers’ University, Xinzhou 034000, Shanxi, China
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Guo JC, Feng LY, Dong C, Zhai HJ. Ternary 12-electron CBe 3X 3+ (X = H, Li, Na, Cu, Ag) clusters: planar tetracoordinate carbons and superalkali cations. Phys Chem Chem Phys 2019; 21:22048-22056. [PMID: 31565718 DOI: 10.1039/c9cp04437j] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Molecules with planar tetracoordinate carbons (ptCs) are exotic in chemical bonding, and they are normally designed according to the 18-electron rule. Here we report on the viability of ptC clusters with as few as 12 valence electrons, which represent the lower limit in terms of electron counting. Specifically, we have computationally designed a class of ternary 12-electron ptC clusters, CBe3X3+ (X = H, Li, Na, Cu, Ag), based on a rhombic CBe32- unit. Computer structural searches reveal that the ptC species are global minima, whose C center is coordinated in-plane by three Be atoms and a terminal X atom via robust C-Be/C-X bonding, either covalent or ionic. The other two X atoms are on the periphery and each bridge two Be atoms. Bonding analyses show that the ptC core is governed by delocalized 2π/6σ bonding, that is, double π/σ aromaticity, which collectively conforms to the 8-electron counting. Additional 4 electrons contribute to peripheral Be-X-Be and Be-Be σ bonding. The delocalized 2π/6σ frameworks appear to be universal for all ptC clusters, ranging from 18-electron down to 12-electron systems. In other words, the ptC species are dictated entirely by the 8-electron counting. Predicted vertical electron affinities of these ptC clusters range from 3.13 to 5.48 eV, indicative of superalkali or pseudoalkali cations.
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Affiliation(s)
- Jin-Chang Guo
- Institute of Environmental Science, Center of Environmental Science and Engineering Research, Shanxi University, Taiyuan 030006, China.
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14
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Cui CX, Xu D, Ding BW, Qu LB, Zhang YP, Lan Y. Benchmark study of popular density functionals for calculating binding energies of three-center two-electron bonds. J Comput Chem 2019; 40:657-670. [PMID: 30565268 DOI: 10.1002/jcc.25752] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 10/19/2018] [Accepted: 10/20/2018] [Indexed: 12/13/2022]
Abstract
Density functional theory (DFT) can be used to study the three-center two-electron (3c2e) bonding mode, which is universal in catalysts containing alkaline-earth (Ae) and boron-group (Bg) elements. However, because of the delocalization pattern of the 3c2e bond, the wavefunction cannot be accurately described by DFT methods. The calculated energies of Ae and Bg catalysts therefore fluctuate greatly when different functionals are used, largely because of inconsistent DFT-calculated binding energies of 3c2e bonds. Nevertheless, with the development of supercomputers and theoretical calculation software, the DFT method is becoming increasingly popular for studying Ae and Bg catalysts. In this study, we compared the performances of 21 functionals with the high-level composite G3B3 method in calculations for the binding energies of 3c2e bonds. Several frequently used post-Hartree-Fock methods were also tested. The calculation results indicate that the M06-2X, MN12-L, and MN15 functionals give consistent and reliable binding energies for common 3c2e bonds. © 2018 Wiley Periodicals, Inc.
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Affiliation(s)
- Cheng-Xing Cui
- Postdoctoral Station of Food Science and Engineering, College of Food Science and Engineering, Henan University of Technology, Zhengzhou 450001, People's Republic of China.,Postdoctoral Research Base, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, People's Republic of China
| | - Dongdong Xu
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People's Republic of China
| | - Bo-Wen Ding
- State Key Laboratory of Water Environment Simulation, School of Environment, Beijing Normal University, Beijing 100875, People's Republic of China
| | - Ling-Bo Qu
- Postdoctoral Station of Food Science and Engineering, College of Food Science and Engineering, Henan University of Technology, Zhengzhou 450001, People's Republic of China.,College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China
| | - Yu-Ping Zhang
- Postdoctoral Research Base, School of Chemistry and Chemical Engineering, Henan Institute of Science and Technology, Xinxiang 453003, People's Republic of China
| | - Yu Lan
- School of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400030, People's Republic of China.,College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, People's Republic of China
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Guo JC, Feng LY, Zhai HJ. Ternary CBe4Au4 cluster: a 16-electron system with quasi-planar tetracoordinate carbon. Phys Chem Chem Phys 2018; 20:6299-6306. [PMID: 29435545 DOI: 10.1039/c7cp08420j] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A ternary CBe4Au4 cluster contains quasi-planar tetracoordinate carbon (quasi-ptC). It adds the new 16-electron counting to ptC complexes, featuring 2π and 6σ double aromaticity.
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Affiliation(s)
- Jin-Chang Guo
- Department of Chemistry
- Xinzhou Teachers University
- Xinzhou 034000
- China
- Nanocluster Laboratory
| | - Lin-Yan Feng
- 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
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Guo J, Chai H, Duan Q, Qin J, Shen X, Jiang D, Hou J, Yan B, Li Z, Gu F, Li Q. Planar tetracoordinate carbon species CLi3E with 12-valence-electrons. Phys Chem Chem Phys 2016; 18:4589-93. [PMID: 26796982 DOI: 10.1039/c5cp06081h] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We exhibit theoretically a series of 12-valence-electron pentaatomic species CLi3E (E = N, P, As, Sb, Bi) and CLi3E(+) (E = O, S, Se, Te, Po). The analyses of potential energy surfaces indicate that the C2v structures with a planar tetracoordinate carbon are the global minimum in these species except for E = N, P. A localized C[double bond, length as m-dash]E double bond is found in the planar tetracoordinate carbon species. The molecular orbitals and the valence populations reveal that the C[double bond, length as m-dash]E double bonds in CLi3E are different from those in CLi3E(+). The thermodynamic and kinetic calculations show that some of the planar tetracoordinate carbon species are stable and are likely to exist in the gas phase.
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Affiliation(s)
- Jiayi Guo
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Haoyu Chai
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Qian Duan
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Jieming Qin
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Xiande Shen
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Dayong Jiang
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Jianhua Hou
- School of Materials Science and Engineering, Changchun University of Science and Technology, Changchun 130022, People's Republic of China.
| | - Bing Yan
- Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, People's Republic of China
| | - Zhiru Li
- Institute of Theoretical Chemistry, Jilin University, Changchun 130012, People's Republic of China
| | - Fenglong Gu
- Center for Computational Quantum Chemistry, South China Normal University, Guangzhou 510631, People's Republic of China.
| | - Qianshu Li
- Center for Computational Quantum Chemistry, South China Normal University, Guangzhou 510631, People's Republic of China.
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