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Sun L, Zheng W, Kang F, Gao W, Wang T, Gao G, Xu W. On-surface synthesis and characterization of anti-aromatic cyclo[12]carbon and cyclo[20]carbon. Nat Commun 2024; 15:7649. [PMID: 39223168 PMCID: PMC11369269 DOI: 10.1038/s41467-024-52115-w] [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: 07/18/2024] [Accepted: 08/26/2024] [Indexed: 09/04/2024] Open
Abstract
Cyclo[n]carbons have recently attracted significant attention owing to their geometric and electronic structures remaining largely unexplored in the condensed phase. In this work, we focus on two anti-aromatic cyclocarbons, namely C12 and C20. By designing two fully halogenated molecular precursors both including 4-numbered rings, we further extend the on-surface retro-Bergman ring-opening reaction, and successfully produce C12 and C20. The polyynic structures of C12 and C20 are unambiguously revealed by bond-resolved atomic force microscopy. More importantly, subtly positioning the C20 molecule into an atomic fence formed by Cl clusters allows us to experimentally probe its frontier molecular orbitals, yielding a transport gap of 3.8 eV measured from scanning tunneling spectroscopy. Our work may advance the field by easier synthesis of a series of cyclocarbons via on-surface retro-Bergman ring-opening strategy.
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Affiliation(s)
- Luye Sun
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China
| | - Wei Zheng
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China
| | - Faming Kang
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China
| | - Wenze Gao
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China
| | - Tongde Wang
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
| | - Guohua Gao
- Shanghai Key Laboratory of Special Artificial Microstructure Materials and Technology, School of Physics Science and Engineering, Tongji University, Shanghai, 200092, People's Republic of China
| | - Wei Xu
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, 201804, People's Republic of China.
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Pooja, Yadav S, Pawar R. Chemistry of Cyclo[18]Carbon (C 18): A Review. CHEM REC 2024; 24:e202400055. [PMID: 38994665 DOI: 10.1002/tcr.202400055] [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: 03/20/2024] [Revised: 05/27/2024] [Indexed: 07/13/2024]
Abstract
Carbon-based allotropes are propelling a technological revolution in communication, sensing, and computing, concurrently challenging fundamental theories of the previous century. Nevertheless, the demand for advanced carbon-based materials remains substantial. The crux lies in the efficient and reliable engineering of novel carbon allotrope. Although C18 has undergone theoretical and experimental investigation for an extended period, its preparation and direct observation in the condensed phase occurred only recently through STM/AFM techniques. The distinctive cyclic ring structure and the dual 18-center π delocalization character introduce various uncommon properties to C18, rendering it a subject worthy of in-depth exploration. In this context, this review delves into past developments contributing to the state-of-the-art understanding of C18 and provides insights into how future endeavours can expedite practical applications. Encompassing a broad spectrum, this review comprehensively investigates almost all facets of C18, including geometric characteristics, electron delocalization, bonding nature, aromaticity, reactivity, electronic excitation, UV/Vis spectrum, intermolecular interaction, response to external fields, electron affinity, ionization, and other molecular properties. Moreover, the review also outlines representative strategies for the direct synthesis and characterization of C18 using atom manipulation techniques. Following this, C18-based complexes are summarized, and potential applications in catalysis, electrochemical devices, optoelectronics, and sensing are discussed.
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Affiliation(s)
- Pooja
- Laboratory of Advanced Computation and Theory for Materials and Chemistry (LACTMC), Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana, 506004, India
| | - Sarita Yadav
- Laboratory of Advanced Computation and Theory for Materials and Chemistry (LACTMC), Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana, 506004, India
| | - Ravinder Pawar
- Laboratory of Advanced Computation and Theory for Materials and Chemistry (LACTMC), Department of Chemistry, National Institute of Technology Warangal (NITW), Warangal, Telangana, 506004, India
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Wu Y, Liu Z, Lu T, Orozco-Ic M, Xu J, Yan X, Wang J, Wang X. Exploring the Aromaticity Differences of Isoelectronic Species of Cyclo[18]carbon (C 18), B 6C 6N 6, and B 9N 9: The Role of Carbon Atoms as Connecting Bridges. Inorg Chem 2023. [PMID: 37988331 DOI: 10.1021/acs.inorgchem.3c02675] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2023]
Abstract
The cyclo[18]carbon (C18) has piqued widespread interest in recent years for its geometrical aesthetic and unique electronic structure. Inspired by it, theoretical investigations of its isoelectronic B9N9 have been published occasionally; however, few studies considered their other companion B6C6N6. In this work, we study the geometric structure, charge distribution, bonding characteristic, aromaticity, and electron delocalization of B6C6N6 and B9N9 for the first time and compare the relevant results with those of C18. Based on the comprehensive analysis of aromaticity indicators such as AV1245, nucleus-independent chemical shifts, anisotropy of the induced current density, magnetically induced current density, iso-chemical shielding surface, and induced magnetic field (Bind), we found that B6C6N6 has definitely a double aromatic character similar to C18 and the aromaticities of the two are very close, while B9N9 is a nonaromatic species. In response to this novel finding, we delved into its nature from an electron delocalization perspective through a localized orbital locator, electron localization function, Fermi hole, and atomic remote delocalization index analyses. The C atom between B and N as an interconnecting bridge strengthens the electron delocalization of the conjugate path, which is the essence of the significant enhancement of the molecular aromaticity from B9N9 to B6C6N6. This work elucidates that within the framework of the isoelectronicity of C18, different methods of atomic doping can achieve molecules with completely different properties.
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Affiliation(s)
- Yang Wu
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Zeyu Liu
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Tian Lu
- Beijing Kein Research Center for Natural Sciences, Beijing 100022, China
| | - Mesías Orozco-Ic
- Donostia International Physics Center (DIPC), Donostia 20018, Euskadi, Spain
| | - Jingbo Xu
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Xiufen Yan
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Jiaojiao Wang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
| | - Xia Wang
- School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212100, China
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Kozáková S, Alharzali N, Černušák I. Cyclo[ n]carbons and catenanes from different perspectives: disentangling the molecular thread. Phys Chem Chem Phys 2023; 25:29386-29403. [PMID: 37901943 DOI: 10.1039/d3cp03887d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2023]
Abstract
All-carbon atomic rings, cyclo[n]carbons, have recently attracted vivid attention of experimentalists and theoreticians. Among them, cyclo[18]carbon is the most studied system. In this paper, we summarize and review various properties of cyclo[n]carbons, emphasising the aspects of their aromaticity/antiaromaticity. In the first part, the trends in bonding patterns and selected aromaticity indices with the increasing size of the rings are discussed. In the second part we explore the properties of catenane models based on interlocked cyclo[18]carbon rings from different perspectives and investigate their behaviour under the action of external force using computational experiments.
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Affiliation(s)
- Silvia Kozáková
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 84215 Bratislava, Slovakia.
| | - Nissrin Alharzali
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 84215 Bratislava, Slovakia.
| | - Ivan Černušák
- Department of Physical and Theoretical Chemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 84215 Bratislava, Slovakia.
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Sun L, Zheng W, Gao W, Kang F, Zhao M, Xu W. On-surface synthesis of aromatic cyclo[10]carbon and cyclo[14]carbon. Nature 2023; 623:972-976. [PMID: 38030782 DOI: 10.1038/s41586-023-06741-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 10/11/2023] [Indexed: 12/01/2023]
Abstract
All-carbon materials based on sp2-hybridized atoms, such as fullerenes1, carbon nanotubes2 and graphene3, have been much explored due to their remarkable physicochemical properties and potential for applications. Another unusual all-carbon allotrope family are the cyclo[n]carbons (Cn) consisting of two-coordinated sp-hybridized atoms. They have been studied in the gas phase since the twentieth century4-6, but their high reactivity has meant that condensed-phase synthesis and real-space characterization have been challenging, leaving their exact molecular structure open to debate7-11. Only in 2019 was an isolated C18 generated on a surface and its polyynic structure revealed by bond-resolved atomic force microscopy12,13, followed by a recent report14 on C16. The C18 work trigged theoretical studies clarifying the structure of cyclo[n]carbons up to C100 (refs. 15-20), although the synthesis and characterization of smaller Cn allotropes remains difficult. Here we modify the earlier on-surface synthesis approach to produce cyclo[10]carbon (C10) and cyclo[14]carbon (C14) via tip-induced dehalogenation and retro-Bergman ring opening of fully chlorinated naphthalene (C10Cl8) and anthracene (C14Cl10) molecules, respectively. We use atomic force microscopy imaging and theoretical calculations to show that, in contrast to C18 and C16, C10 and C14 have a cumulenic and cumulene-like structure, respectively. Our results demonstrate an alternative strategy to generate cyclocarbons on the surface, providing an avenue for characterizing annular carbon allotropes for structure and stability.
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Affiliation(s)
- Luye Sun
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China
| | - Wei Zheng
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China
| | - Wenze Gao
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China
| | - Faming Kang
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China
| | - Mali Zhao
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China
| | - Wei Xu
- Interdisciplinary Materials Research Center, School of Materials Science and Engineering, Tongji University, Shanghai, People's Republic of China.
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Trapping of Small Molecules within Single or Double Cyclo[18]carbon Rings. Molecules 2023; 28:molecules28052157. [PMID: 36903404 PMCID: PMC10004474 DOI: 10.3390/molecules28052157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/22/2023] [Accepted: 02/23/2023] [Indexed: 03/02/2023] Open
Abstract
The encapsulation of a set of small molecules, H2, CO, CO2, SO2, and SO3, by a circular C18 ring is investigated by quantum calculations. These ligands lie near the center of the ring but, with the exception of H2, are disposed roughly perpendicular to the ring plane. Their binding energies with the C18 vary from 1.5 kcal/mol for H2 up to 5.7 kcal/mol for SO2, and the bonding is dominated by dispersive interactions spread over the entire ring. The binding of these ligands on the outside of the ring is weaker but allows the opportunity for each to bond covalently with the ring. A pair of C18 units lie parallel to one another. This pair can bind each of these ligands in the area between them with only small perturbations of the double ring geometry. The binding energies of these ligands to this double ring configuration are amplified by some 50% compared to the single ring systems. The presented data concerning the trapping of small molecules may have larger implications regarding hydrogen storage or air pollution reduction.
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