1
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Song S, Pinar Solé A, Matěj A, Li G, Stetsovych O, Soler D, Yang H, Telychko M, Li J, Kumar M, Chen Q, Edalatmanesh S, Brabec J, Veis L, Wu J, Jelinek P, Lu J. Highly entangled polyradical nanographene with coexisting strong correlation and topological frustration. Nat Chem 2024; 16:938-944. [PMID: 38374456 DOI: 10.1038/s41557-024-01453-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 01/17/2024] [Indexed: 02/21/2024]
Abstract
Open-shell nanographenes exhibit unconventional π-magnetism arising from topological frustration or strong electron-electron interaction. However, conventional design approaches are typically limited to a single magnetic origin, which can restrict the number of correlated spins or the type of magnetic ordering in open-shell nanographenes. Here we present a design strategy that combines topological frustration and electron-electron interactions to fabricate a large fully fused 'butterfly'-shaped tetraradical nanographene on Au(111). We employ bond-resolved scanning tunnelling microscopy and spin-excitation spectroscopy to resolve the molecular backbone and reveal the strongly correlated open-shell character, respectively. This nanographene contains four unpaired electrons with both ferromagnetic and anti-ferromagnetic interactions, harbouring a many-body singlet ground state and strong multi-spin entanglement, which is well described by many-body calculations. Furthermore, we study the magnetic properties and spin states in the nanographene using a nickelocene magnetic probe. The ability to imprint and characterize many-body strongly correlated spins in polyradical nanographenes paves the way for future advancements in quantum information technologies.
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Affiliation(s)
- Shaotang Song
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Andrés Pinar Solé
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic
| | - Adam Matěj
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic
| | - Guangwu Li
- Department of Chemistry, National University of Singapore, Singapore, Singapore
- Center of Single-Molecule Sciences, Frontiers Science Center for New Organic Matter, College of Electronic Information and Optical Engineering, Nankai University, Tianjin, China
| | | | - Diego Soler
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Huimin Yang
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Mykola Telychko
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Jing Li
- Department of Chemistry, National University of Singapore, Singapore, Singapore
| | - Manish Kumar
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | - Qifan Chen
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic
| | | | - Jiri Brabec
- Department of Theoretical Chemistry, J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic
| | - Libor Veis
- Department of Theoretical Chemistry, J. Heyrovsky Institute of Physical Chemistry, Czech Academy of Sciences, Prague, Czech Republic.
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, Singapore, Singapore.
| | - Pavel Jelinek
- Institute of Physics, Czech Academy of Sciences, Prague, Czech Republic.
- Regional Centre of Advanced Technologies and Materials, Czech Advanced Technology and Research Institute, Palacký University Olomouc, Olomouc, Czech Republic.
| | - Jiong Lu
- Department of Chemistry, National University of Singapore, Singapore, Singapore.
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore, Singapore.
- National University of Singapore (Suzhou) Research Institute, Suzhou, China.
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2
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Spalenza PEP, de Souza FAL, Amorim RG, Scheicher RH, Scopel WL. A high density nanopore 3-triangulene kagome lattice. NANOSCALE 2024; 16:9911-9916. [PMID: 38686534 DOI: 10.1039/d4nr00910j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
Nanopore-containing two-dimensional materials have been explored for a wide range of applications including filtration, sensing, catalysis, energy storage and conversion. Triangulenes have recently been experimentally synthesized in a variety of sizes. In this regard, using these systems as building blocks, we theoretically examined 3-triangulene kagome crystals with inherent holes of ∼12 Å diameter and a greater density array of nanopores (≥1013 cm-2) compared to conventional 2D systems. The energetic, electronic, and transport properties of pristine and B/N-doped 3-triangulene kagome crystals were evaluated through a combination of density functional theory and non-equilibrium Green's function method. The simulated scanning tunneling microscopy images clearly capture electronic perturbation around the doped sites, which can be used to distinguish the pristine system from the doped systems. The viability of precisely controlling the band structure and transport properties by changing the type and concentration of doping atoms is demonstrated. The findings presented herein can potentially widen the applicability of these systems that combine unique electronic properties and intrinsically high-density pores, which can pave the way for the next generation of nanopore-based devices.
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Affiliation(s)
| | | | - Rodrigo G Amorim
- Departamento de Física, ICEx, Universidade Federal Fluminense - UFF, Volta Redonda, RJ, Brazil.
| | - Ralph H Scheicher
- Division of Materials Theory, Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
| | - Wanderlã Luis Scopel
- Departamento de Física, Universidade Federal do Espírito Santo - UFES, Vitória, ES, Brazil.
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3
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Izu AE, Matxain JM, Casanova D. Reverse intersystem crossing mechanisms in doped triangulenes. Phys Chem Chem Phys 2024; 26:11459-11468. [PMID: 38563957 DOI: 10.1039/d4cp00304g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Thermally activated delayed fluorescence (TADF) has emerged as one of the most promising strategies in the quest for organic light emitting diodes with optimal performance. This computational study dissects the mechanistic intricacies of the central photophysical step, reverse intersystem crossing (rISC) in N and B doped triangulenes as potential multi-resonance TADF compounds. Optimal molecular patterns conducive to efficient rISC, encompassing dopant atom size, number, and distribution, are identified. Additionally, we assess various electronic structure methods for characterizing TADF-relevant molecular systems. The findings identify the distinct role of the direct and mediated mechanisms in rISC, and provide insights into the design of advanced TADF chromophores for next-generation OLED technology.
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Affiliation(s)
- Asier E Izu
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain.
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), PK 1072, 20080 Donostia, Euskadi, Spain
| | - Jon M Matxain
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain.
- Polimero eta Material Aurreratuak: Fisika, Kimika eta Teknologia Saila, Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU), PK 1072, 20080 Donostia, Euskadi, Spain
| | - David Casanova
- Donostia International Physics Center (DIPC), 20018 Donostia, Euskadi, Spain.
- IKERBASQUE, Basque Foundation for Science, 48009 Bilbao, Euskadi, Spain
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4
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Xu S, Zhang Y, Zang C, Liu J, Jin W, Lefkidis G, Hübner W, Li C. Unlocking Ultrafast Spin Transfer in Single-Magnetic-Center-Decorated Triangulene Systems. J Phys Chem Lett 2024; 15:3929-3937. [PMID: 38568181 DOI: 10.1021/acs.jpclett.4c00469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/12/2024]
Abstract
Triangulene, as a typical open-shell graphene fragment, has attracted widespread attention for nanospintronics, promising to serve as building blocks in spin-logic units. Here, using ab initio calculations, we systematically study the laser-induced ultrafast spin-dynamic processes on triangulene nanoflakes, decorated with a transition-metal atom. The results reveal a competition between the induced magnetic center and the carbon edge of the triangulene, resulting in the coexistence of dual spin-density-distribution patterns on such single-magnetic-center systems, thus opening up possibilities of complex spin-dynamic scenarios beyond the spin flip. Interestingly, no matter what direction the spin points to, it is possible to achieve reversible spin-transfer processes using the same laser pulse. Increasing the pool of elementary processes to contain not only spin-direction-dependent but also spin-direction-independent scenarios allows for more versatile spin-logic operations, including classical handling of information and quantum computing. In the present work, we suggest downscaling nanospintronic devices by integrating triangulene-based nanostructures.
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Affiliation(s)
- Shuai Xu
- Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China
| | - Yiming Zhang
- Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
- School of Science, Xi'an University of Architecture and Technology, Xi'an 710055, China
| | - Congfei Zang
- Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China
| | - Jing Liu
- Institute of Theoretical Chemistry, Ulm University, 89081 Ulm, Germany
| | - Wei Jin
- School of Physics and Information Technology, Shaanxi Normal University, Xi'an 710119, China
| | - Georgios Lefkidis
- Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
- Department of Physics, RPTU Kaiserslautern-Landau, P.O. Box 3049, 67653 Kaiserslautern, Germany
| | - Wolfgang Hübner
- Department of Physics, RPTU Kaiserslautern-Landau, P.O. Box 3049, 67653 Kaiserslautern, Germany
| | - Chun Li
- Department of Engineering Mechanics, Northwestern Polytechnical University, Xi'an 710072, China
- Research & Development Institute of Northwestern Polytechnical University in Shenzhen, Shenzhen 518057, China
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5
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Zhu X, Li K, Liu J, Wang Z, Ding Z, Su Y, Yang B, Yan K, Li G, Yu P. Topological Structure Realized in Cove-Edged Graphene Nanoribbons via Incorporation of Periodic Pentagon Rings. J Am Chem Soc 2024; 146:7152-7158. [PMID: 38421279 DOI: 10.1021/jacs.4c00270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Cove-edged zigzag graphene nanoribbons are predicted to show metallic, topological, or trivial semiconducting band structures, which are precisely determined by their cove offset positions at both edges as well as the ribbon width. However, due to the challenge of introducing coves into zigzag-edged graphene nanoribbons, only a few cove-edged graphene nanoribbons with trivial semiconducting bandgaps have been realized experimentally. Here, we report that the topological band structure can be realized in cove-edged graphene nanoribbons by embedding periodic pentagon rings on the cove edges through on-surface synthesis. Upon noncontact atomic force microscopy and scanning tunneling spectroscopy measurements, the chemical and electronic structures of cove-edged graphene nanoribbons with periodic pentagon rings have been characterized for different lengths. Combined with theoretical calculations, we find that upon inducing periodic pentagon rings the cove-edged graphene nanoribbons exhibit nontrivial topological structures. Our results provide insights for the design and understanding of the topological character in cove-edged graphene nanoribbons.
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Affiliation(s)
- Xujie Zhu
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Kezhen Li
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Jian Liu
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Zhou Wang
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Zhihao Ding
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Yunlong Su
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Bo Yang
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - KaKing Yan
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
| | - Gang Li
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
- ShanghaiTech Laboratory for Topological Physics, ShanghaiTech University, 201210 Shanghai, China
| | - Ping Yu
- School of Physical Science and Technology, ShanghaiTech University, 201210 Shanghai, China
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6
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Inoue T, Matsuura Y, Horii K, Konishi A, Nishida JI, Yasuda M, Kawase T. N-2,6-Di(isopropyl)phenyl-2-azaphenalenyl radical cations. Chem Commun (Camb) 2024; 60:1735-1738. [PMID: 38240365 DOI: 10.1039/d3cc05968e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
N-2,6-Di(isopropyl)phenyl-2-azaphenalenyl radical cations were obtained as a dark brown air-sensitive crystalline compound. The high HOMA values and the ACID calculation indicate relatively high aromatic character of a 5,8-di-tert-butyl derivative, and clean generation of a derivative without tert-butyl groups indicates that the di(isopropyl)phenyl group is sufficient for hampering the formation of the σ-dimer.
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Affiliation(s)
- Takeru Inoue
- Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280, Japan.
| | - Yuuka Matsuura
- Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280, Japan.
| | - Koki Horii
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
| | - Akihito Konishi
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Jun-Ichi Nishida
- Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280, Japan.
| | - Makoto Yasuda
- Department of Applied Chemistry, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871, Japan.
- Innovative Catalysis Science Division, Institute for Open and Transdisciplinary Research Initiatives (ICS-OTRI), Osaka University, Suita, Osaka 565-0871, Japan
| | - Takeshi Kawase
- Graduate School of Engineering, University of Hyogo, Himeji, Hyogo 671-2280, Japan.
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7
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Zhao C, Huang Q, Valenta L, Eimre K, Yang L, Yakutovich AV, Xu W, Ma J, Feng X, Juríček M, Fasel R, Ruffieux P, Pignedoli CA. Tailoring Magnetism of Graphene Nanoflakes via Tip-Controlled Dehydrogenation. PHYSICAL REVIEW LETTERS 2024; 132:046201. [PMID: 38335341 DOI: 10.1103/physrevlett.132.046201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/14/2023] [Accepted: 12/15/2023] [Indexed: 02/12/2024]
Abstract
Atomically precise graphene nanoflakes called nanographenes have emerged as a promising platform to realize carbon magnetism. Their ground state spin configuration can be anticipated by Ovchinnikov-Lieb rules based on the mismatch of π electrons from two sublattices. While rational geometrical design achieves specific spin configurations, further direct control over the π electrons offers a desirable extension for efficient spin manipulations and potential quantum device operations. To this end, we apply a site-specific dehydrogenation using a scanning tunneling microscope tip to nanographenes deposited on a Au(111) substrate, which shows the capability of precisely tailoring the underlying π-electron system and therefore efficiently manipulating their magnetism. Through first-principles calculations and tight-binding mean-field-Hubbard modeling, we demonstrate that the dehydrogenation-induced Au-C bond formation along with the resulting hybridization between frontier π orbitals and Au substrate states effectively eliminate the unpaired π electron. Our results establish an efficient technique for controlling the magnetism of nanographenes.
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Affiliation(s)
- Chenxiao Zhao
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Qiang Huang
- Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden 01062, Germany
| | - Leoš Valenta
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Kristjan Eimre
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Lin Yang
- Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden 01062, Germany
| | - Aliaksandr V Yakutovich
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Wangwei Xu
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern 3012, Switzerland
| | - Ji Ma
- Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden 01062, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle 06120, Germany
| | - Xinliang Feng
- Faculty of Chemistry and Food Chemistry, and Center for Advancing Electronics Dresden, Technical University of Dresden, Dresden 01062, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, Halle 06120, Germany
| | - Michal Juríček
- Department of Chemistry, University of Zurich, Zurich 8057, Switzerland
| | - Roman Fasel
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
- Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, Bern 3012, Switzerland
| | - Pascal Ruffieux
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
| | - Carlo A Pignedoli
- Empa-Swiss Federal Laboratories for Materials Science and Technology, Dübendorf 8600, Switzerland
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8
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Ruan L, Luo W, Zhang H, Liu P, Shi Y, An P. Cycl[2,2,4]azine-embedded non-alternant nanographenes containing fused antiaromatic azepine ring. Chem Sci 2024; 15:1511-1519. [PMID: 38274082 PMCID: PMC10806646 DOI: 10.1039/d3sc05515a] [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: 10/17/2023] [Accepted: 12/14/2023] [Indexed: 01/27/2024] Open
Abstract
The development of non-alternant nanographenes has attracted considerable attention due to their unique photophysical properties. Herein, we reported a novel aza-doped, non-alternant nanographene (NG) 1 by embedding the cycl[2,2,4]azine unit into the benzenoid NG framework. Single-crystal X-ray diffractometry suggests saddle or twisted nonplanar geometry of the entire backbone of 1 and coplanar conformation of the cycl[2,2,4]azine unit. DFT calculation together with solid structure indicates that NG 1 possesses significant local antiaromaticity in the azepine ring. By oxidative process or trifluoroacetic acid treatment, this nanographene can transform into a mono-radical cation, which was confirmed by UV/Vis absorption, 1H NMR, and electron paramagnetic resonance (EPR) spectroscopy. The antiaromaticity/aromaticity switching of the azepine ring on 1˙+ from 1 enables the high stability of this radical cation, which remained intact for over 1 day. Due to the electron-donating nature of the nitrogen and the unique electronic structure, NG 1 exhibits strong electron-donating properties, as proved by the intermolecular charge transfer towards C60 with a high association constant. Furthermore, selective modification of NG 1 was accomplished by Vilsmeier reaction, and the derivatives 7 and 8 with substituted benzophenone were obtained. The photophysical and electronic properties can be tuned by the introduction of different electronic groups in benzophenone.
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Affiliation(s)
- Lan Ruan
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Wanhua Luo
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Haifan Zhang
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Peng Liu
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Yong Shi
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
| | - Peng An
- School of Chemical Science and Technology, Yunnan University Kunming 650091 P. R. China
- Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan University Kunming 650091 P. R. China
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9
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Jacobse P, Daugherty MC, Čerņevičs K, Wang Z, McCurdy RD, Yazyev OV, Fischer FR, Crommie MF. Five-Membered Rings Create Off-Zero Modes in Nanographene. ACS NANO 2023; 17:24901-24909. [PMID: 38051766 PMCID: PMC10753889 DOI: 10.1021/acsnano.3c06006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2023] [Revised: 11/18/2023] [Accepted: 12/01/2023] [Indexed: 12/07/2023]
Abstract
The low-energy electronic structure of nanographenes can be tuned through zero-energy π-electron states, typically referred to as zero-modes. Customizable electronic and magnetic structures have been engineered by coupling zero-modes through exchange and hybridization interactions. Manipulation of the energy of such states, however, has not yet received significant attention. We find that attaching a five-membered ring to a zigzag edge hosting a zero-mode perturbs the energy of that mode and turns it into an off-zero mode: a localized state with a distinctive electron-accepting character. Whereas the end states of typical 7-atom-wide armchair graphene nanoribbons (7-AGNRs) lose their electrons when physisorbed on Au(111) (due to its high work function), converting them into off-zero modes by introducing cyclopentadienyl five-membered rings allows them to retain their single-electron occupation. This approach enables the magnetic properties of 7-AGNR end states to be explored using scanning tunneling microscopy (STM) on a gold substrate. We find a gradual decrease of the magnetic coupling between off-zero mode end states as a function of GNR length, and evolution from a more closed-shell to a more open-shell ground state.
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Affiliation(s)
- Peter
H. Jacobse
- Department
of Physics, University of California, Berkeley, California 94720, United States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
| | - Michael C. Daugherty
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Kristia̅ns Čerņevičs
- Institute
of Physics, Ecole Polytechnique Fédérale
de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Ziyi Wang
- Department
of Physics, University of California, Berkeley, California 94720, United States
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Kavli
Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Ryan D. McCurdy
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | - Oleg V. Yazyev
- Institute
of Physics, Ecole Polytechnique Fédérale
de Lausanne (EPFL), 1015 Lausanne, Switzerland
| | - Felix R. Fischer
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Kavli
Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
- Bakar
Institute
of Digital Materials for the Planet, Division of Computing, Data Science,
and Society, University of California, Berkeley, California 94720, United States
| | - Michael F. Crommie
- Department
of Physics, University of California, Berkeley, California 94720, United States
- Materials
Sciences Division, Lawrence Berkeley National
Laboratory, Berkeley, California 94720, United States
- Kavli
Energy NanoSciences Institute at the University of California, Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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10
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Zhang H, Lu J, Zhao XJ, Li B, Zhou H, Zhang Y, Niu G, Fu B, Gao L, Tan YZ, Cai J. Length-Dependent Magnetic Evolution of Anthenes on Au(111). Angew Chem Int Ed Engl 2023; 62:e202315216. [PMID: 37933811 DOI: 10.1002/anie.202315216] [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: 10/09/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 11/08/2023]
Abstract
Nanographenes with zigzag edges, for example, anthenes, exhibit a unique nonbonding π-electron state, which can be described as a spin-polarized edge state that yields specific magnetic ground state. However, prior researches on the magnetism of anthenes with varying lengths on a surface is lacking. This study systematically fabricated anthenes with inherent zigzag carbon atoms of different lengths ranging from bisanthene to hexanthene. Their magnetic evolution on the Au(111) surface was analyzed through bond-resolved scanning probe techniques and density functional theory calculations. The analyses revealed a transition in magnetic properties associated with the length of the anthenes, arising from the imbalance between hybridization energy and the Coulomb repulsion between valence electrons. With the increasing length of the anthenes, the ground state transforms gradually from a closed-shell to an antiferromagnetic open-shell singlet, exhibiting a weak exchange coupling of 4 meV and a charge transfer-induced doublet. Therefore, this study formulated a chemically tunable platform to explore size-dependent π magnetism at the atomic scale, providing a framework for research in organic spintronics.
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Affiliation(s)
- Hui Zhang
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Jianchen Lu
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Xin-Jing Zhao
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Baijin Li
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Hangjing Zhou
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Yong Zhang
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Gefei Niu
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Boyu Fu
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
| | - Lei Gao
- Faculty of Science, Kunming University of Science and Technology, Kunming, 650500, China
| | - Yuan-Zhi Tan
- State Key Laboratory for Physical Chemistry of Solid Surfaces, Collaborative Innovation Center of Chemistry for Energy Materials, and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, 361005, China
| | - Jinming Cai
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, Kunming, 650093, China
- Southwest United Graduate School, Kunming, 650093, China
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11
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Calupitan JP, Berdonces-Layunta A, Aguilar-Galindo F, Vilas-Varela M, Peña D, Casanova D, Corso M, de Oteyza DG, Wang T. Emergence of π-Magnetism in Fused Aza-Triangulenes: Symmetry and Charge Transfer Effects. NANO LETTERS 2023; 23:9832-9840. [PMID: 37870305 PMCID: PMC10722538 DOI: 10.1021/acs.nanolett.3c02586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 10/16/2023] [Accepted: 10/17/2023] [Indexed: 10/24/2023]
Abstract
On-surface synthesis has paved the way toward the fabrication and characterization of conjugated carbon-based molecular materials that exhibit π-magnetism such as triangulenes. Aza-triangulene, a nitrogen-substituted derivative, was recently shown to display rich on-surface chemistry, offering an ideal platform to investigate structure-property relations regarding spin-selective charge transfer and magnetic fingerprints. Herein, we study electronic changes upon fusion of single molecules into larger dimeric derivatives. We show that the closed-shell structure of aza-triangulene on Ag(111) leads to closed-shell dimers covalently coupled through sterically accessible carbon atoms. Meanwhile, its open-shell structure on Au(111) leads to coupling via atoms displaying a high spin density, resulting in symmetric or asymmetric products. Interestingly, whereas all dimers on Au(111) exhibit similar charge transfer properties, only asymmetric ones show magnetic fingerprints due to spin-selective charge transfer. These results expose clear relationships among molecular symmetry, charge transfer, and spin states of π-conjugated carbon-based nanostructures.
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Affiliation(s)
- Jan Patrick Calupitan
- Centro
de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
- Donostia
International Physics Center, 20018 San Sebastián, Spain
| | - Alejandro Berdonces-Layunta
- Centro
de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
- Donostia
International Physics Center, 20018 San Sebastián, Spain
| | - Fernando Aguilar-Galindo
- Departamento
de Química, Universidad Autónoma
de Madrid, 28049 Madrid, Spain
- Institute
for Advanced Research in Chemical Sciences (IAdChem), Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Manuel Vilas-Varela
- Centro
Singular de Investigación en Química Biolóxica
e Materiais Moleculares (CiQUS) and Departamento de Química
Orgánica, Universidade de Santiago
de Compostela, 15782 Santiago de Compostela, Spain
| | - Diego Peña
- Centro
Singular de Investigación en Química Biolóxica
e Materiais Moleculares (CiQUS) and Departamento de Química
Orgánica, Universidade de Santiago
de Compostela, 15782 Santiago de Compostela, Spain
| | - David Casanova
- Donostia
International Physics Center, 20018 San Sebastián, Spain
- Ikerbasque, Basque Foundation
for Science, 48009 Bilbao, Spain
| | - Martina Corso
- Centro
de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
- Donostia
International Physics Center, 20018 San Sebastián, Spain
| | - Dimas G. de Oteyza
- Centro
de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
- Donostia
International Physics Center, 20018 San Sebastián, Spain
- Nanomaterials
and Nanotechnology Research Center (CINN), CSIC-UNIOVI-PA, 33940 El Entrego, Spain
| | - Tao Wang
- Centro
de Física de Materiales (CFM-MPC), CSIC-UPV/EHU, 20018 San Sebastián, Spain
- Donostia
International Physics Center, 20018 San Sebastián, Spain
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12
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Shu C, Yang Z, Rajca A. From Stable Radicals to Thermally Robust High-Spin Diradicals and Triradicals. Chem Rev 2023; 123:11954-12003. [PMID: 37831948 DOI: 10.1021/acs.chemrev.3c00406] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2023]
Abstract
Stable radicals and thermally robust high-spin di- and triradicals have emerged as important organic materials due to their promising applications in diverse fields. New fundamental properties, such as SOMO/HOMO inversion of orbital energies, are explored for the design of new stable radicals, including highly luminescent ones with good photostability. A relation with the singlet-triplet energy gap in the corresponding diradicals is proposed. Thermally robust high-spin di- and triradicals, with energy gaps that are comparable to or greater than a thermal energy at room temperature, are more challenging to synthesize but more rewarding. We summarize a number of high-spin di- and triradicals, based on nitronyl nitroxides that provide a relation between the experimental pairwise exchange coupling constant J/k in the high-spin species vs experimental hyperfine coupling constants in the corresponding monoradicals. This relation allows us to identify outliers, which may correspond to radicals where J/k is not measured with sufficient accuracy. Double helical high-spin diradicals, in which spin density is delocalized over the chiral π-system, have been barely explored, with the sole example of such high-spin diradical possessing alternant π-system with Kekulé resonance form. Finally, we discuss a high-spin diradical with electrical conductivity and derivatives of triangulene diradicals.
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Affiliation(s)
- Chan Shu
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Zhimin Yang
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, Nebraska 68588-0304, United States
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13
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Lawrence J, He Y, Wei H, Su J, Song S, Wania Rodrigues A, Miravet D, Hawrylak P, Zhao J, Wu J, Lu J. Topological Design and Synthesis of High-Spin Aza-triangulenes without Jahn-Teller Distortions. ACS NANO 2023; 17:20237-20245. [PMID: 37791737 DOI: 10.1021/acsnano.3c05974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/05/2023]
Abstract
The atomic doping of open-shell nanographenes enables precise tuning of their electronic and magnetic states, which is crucial for their promising potential applications in optoelectronics and spintronics. Among this intriguing class of molecules, triangulenes stand out with their size-dependent electronic properties and spin states, which can also be influenced by the presence of dopant atoms and functional groups. However, the occurrence of Jahn-Teller distortions in such systems can have a crucial impact on their total spin and requires further theoretical and experimental investigation. In this study, we examine the nitrogen-doped aza-triangulene series via a combination of density functional theory and on-surface synthesis. We identify a general trend in the calculated spin states of aza-[n]triangulenes of various sizes, separating them into two symmetry classes, one of which features molecules that are predicted to undergo Jahn-Teller distortions that reduce their symmetry and thus their total spin. We link this behavior to the location of the central nitrogen atom relative to the two underlying carbon sublattices of the molecules. Consequently, our findings reveal that neutral centrally doped aza-triangulenes have one less radical than their undoped counterparts, irrespective of their predicted symmetry. We follow this by demonstrating the on-surface synthesis of π-extended aza-[5]triangulene, a large member of the higher symmetry class without Jahn-Teller distortions, via a simple one-step annealing process on Cu(111) and Au(111). Using scanning probe microscopy and spectroscopy combined with theoretical calculations, we prove that the molecule is positively charged on the Au(111) substrate, with a high-spin quintet state of S = 2, the same total spin as undoped neutral [5]triangulene. Our study uncovers the correlation between the dopant position and the radical nature of high-spin nanographenes, providing a strategy for the design and development of these nanographenes for various applications.
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Affiliation(s)
- James Lawrence
- Department of Chemistry, National University of Singapore, 117543 Singapore
| | - Yuanyuan He
- College of Material and Textile Engineering, Key Laboratory of Yarn Materials Forming and Composite Processing Technology of Zhejiang Province, Jiaxing University, Jiaxing 314001, Zhejiang, People's Republic of China
| | - Haipeng Wei
- Department of Chemistry, National University of Singapore, 117543 Singapore
| | - Jie Su
- Department of Chemistry, National University of Singapore, 117543 Singapore
| | - Shaotang Song
- Department of Chemistry, National University of Singapore, 117543 Singapore
| | | | - Daniel Miravet
- Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Pawel Hawrylak
- Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
- Institute for Functional Intelligent Materials, National University of Singapore, 117544 Singapore
| | - Jianwei Zhao
- College of Material and Textile Engineering, Key Laboratory of Yarn Materials Forming and Composite Processing Technology of Zhejiang Province, Jiaxing University, Jiaxing 314001, Zhejiang, People's Republic of China
| | - Jishan Wu
- Department of Chemistry, National University of Singapore, 117543 Singapore
| | - Jiong Lu
- Department of Chemistry, National University of Singapore, 117543 Singapore
- Institute for Functional Intelligent Materials, National University of Singapore, 117544 Singapore
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14
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Wang Y, Wang Z, Qiu Z, Zhang X, Chen J, Li J, Narita A, Müllen K, Palma CA. Hydrogenation of Hexa- peri-hexabenzocoronene: An Entry to Nanographanes and Nanodiamonds. ACS NANO 2023; 17:18832-18842. [PMID: 37729013 DOI: 10.1021/acsnano.3c03538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
The fabrication of atomically precise nanographanes is a largely unexplored frontier in carbon-sp3 nanomaterials, enabling potential applications in phononics, photonics and electronics. One strategy is the hydrogenation of prototypical nanographene monolayers and multilayers under vacuum conditions. Here, we study the interaction of atomic hydrogen, generated by a hydrogen source and hydrogen plasma, with hexa-peri-hexabenzocoronene on gold using integrated time-of-flight mass spectrometry, scanning tunneling microscopy and Raman spectroscopy. Density functional tight-binding molecular dynamics is employed to rationalize the conversion to sp3 carbon atoms. The resulting hydrogenation of hexa-peri-hexabenzocoronene molecules is demonstrated computationally and experimentally, and the potential for atomically precise hexa-peri-hexabenzocoronene-derived nanodiamond fabrication is proposed.
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Affiliation(s)
- Yan Wang
- School of Physics, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, People's Republic of China
| | - Zishu Wang
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, People's Republic of China
- University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
| | - Zijie Qiu
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Xiaoxi Zhang
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, People's Republic of China
- University of Chinese Academy of Sciences, 100049 Beijing, People's Republic of China
| | - Jianing Chen
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, People's Republic of China
| | - Juan Li
- School of Physics, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
- Advanced Research Institute of Multidisciplinary Sciences, Beijing Institute of Technology, 100081 Beijing, People's Republic of China
| | - Akimitsu Narita
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Klaus Müllen
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Carlos-Andres Palma
- Institute of Physics, Chinese Academy of Sciences, 100190 Beijing, People's Republic of China
- Department of Physics & IRIS Adlershof, Humboldt-Universität zu Berlin, Newtonstraße 15, 12489 Berlin, Germany
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15
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Vilas-Varela M, Romero-Lara F, Vegliante A, Calupitan JP, Martínez A, Meyer L, Uriarte-Amiano U, Friedrich N, Wang D, Schulz F, Koval NE, Sandoval-Salinas ME, Casanova D, Corso M, Artacho E, Peña D, Pascual JI. On-Surface Synthesis and Characterization of a High-Spin Aza-[5]-Triangulene. Angew Chem Int Ed Engl 2023; 62:e202307884. [PMID: 37604782 DOI: 10.1002/anie.202307884] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/11/2023] [Accepted: 08/17/2023] [Indexed: 08/23/2023]
Abstract
Triangulenes are a class of open-shell triangular graphene flakes with total spin increasing with their size. In the last years, on-surface-synthesis strategies have permitted fabricating and engineering triangulenes of various sizes and structures with atomic precision. However, direct proof of the increasing total spin with their size remains elusive. In this work, we report the combined in-solution and on-surface synthesis of a large nitrogen-doped triangulene (aza-[5]-triangulene) on a Au(111) surface, and the detection of its high-spin ground state. Bond-resolved scanning tunneling microscopy images uncovered radical states distributed along the zigzag edges, which were detected as weak zero-bias resonances in scanning tunneling spectra. These spectral features reveal the partial Kondo screening of a high-spin state. Through a combination of several simulation tools, we find that the observed distribution of radical states is explained by a quintet ground state (S=2), instead of the quartet state (S=3/2) expected for the neutral species. This confirms that electron transfer to the metal substrate raises the spin of the ground state. We further provide a qualitative description of the change of (anti)aromaticity introduced by N-substitution, and its role in the charge stabilization on a surface, resulting in an S=2 aza-triangulene on Au(111).
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Affiliation(s)
- Manuel Vilas-Varela
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-, Santiago de Compostela, Spain
| | | | | | - Jan Patrick Calupitan
- Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, 20018, Donostia-San Sebastián, Spain
- Donostia International Physics Center (DIPC), 20018, Donostia-San Sebastián, Spain
| | - Adrián Martínez
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-, Santiago de Compostela, Spain
| | - Lorenz Meyer
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
| | | | | | - Dongfei Wang
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
| | - Fabian Schulz
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
| | | | | | - David Casanova
- Donostia International Physics Center (DIPC), 20018, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
| | - Martina Corso
- Centro de Física de Materiales CSIC/UPV-EHU-Materials Physics Center, 20018, Donostia-San Sebastián, Spain
| | - Emilio Artacho
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
- Theory of Condensed Matter, Cavendish Laboratory, University of Cambridge, J. J. Thomson Ave., Cambridge, CB3 0HE, UK
| | - Diego Peña
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CiQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782-, Santiago de Compostela, Spain
| | - José Ignacio Pascual
- CIC nanoGUNE-BRTA, 20018, Donostia-San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, 48009, Bilbao, Spain
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16
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Yu H, Heine T. Magnetic Coupling Control in Triangulene Dimers. J Am Chem Soc 2023; 145:19303-19311. [PMID: 37610306 PMCID: PMC10485925 DOI: 10.1021/jacs.3c05178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Indexed: 08/24/2023]
Abstract
Metal-free magnetism remains an enigmatic field, offering prospects for unconventional magnetic and electronic devices. In the pursuit of such magnetism, triangulenes, endowed with inherent spin polarization, are promising candidates to serve as monomers to construct extended structures. However, controlling and enhancing the magnetic interactions between the monomers persist as a significant challenge in molecular spintronics, as so far only weak antiferromagnetic coupling through the linkage has been realized, hindering their room temperature utilization. Herein, we investigate 24 triangulene dimers using first-principles calculations and demonstrate their tunable magnetic coupling (J), achieving unprecedented strong J values of up to -144 meV in a non-Kekulé dimer. We further establish a positive correlation between bandgap, electronic coupling, and antiferromagnetic interaction, thereby providing molecular-level insights into enhancing magnetic interactions. By twisting the molecular fragments, we demonstrate an effective and feasible approach to control both the sign and strength of J by tuning the balance between potential and kinetic exchanges. We discover that J can be substantially boosted at planar configurations up to -198 meV. We realize ferromagnetic coupling in nitrogen-doped triangulene dimers at both planar and largely twisted configurations, representing the first example of ferromagnetic triangulene dimers that cannot be predicted by the Ovchinnikov rule. This work thus provides a practical strategy for augmenting magnetic coupling and open up new avenues for metal-free ferromagnetism.
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Affiliation(s)
- Hongde Yu
- Faculty
of Chemistry and Food Chemistry, Technische
Universität Dresden, Bergstraße 66c, 01062 Dresden, Germany
| | - Thomas Heine
- Faculty
of Chemistry and Food Chemistry, Technische
Universität Dresden, Bergstraße 66c, 01062 Dresden, Germany
- Institute
of Resource Ecology, Helmholtz Zentrum Dresden-Rossendorf, Permoserstraße 15, 04318 Leipzig, Germany
- Department
of Chemistry, Yonsei University, Seodaemun-gu, Seoul 120-749, Republic of Korea
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17
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Du Q, Su X, Liu Y, Jiang Y, Li C, Yan K, Ortiz R, Frederiksen T, Wang S, Yu P. Orbital-symmetry effects on magnetic exchange in open-shell nanographenes. Nat Commun 2023; 14:4802. [PMID: 37558678 PMCID: PMC10412602 DOI: 10.1038/s41467-023-40542-0] [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: 09/30/2022] [Accepted: 08/01/2023] [Indexed: 08/11/2023] Open
Abstract
Open-shell nanographenes appear as promising candidates for future applications in spintronics and quantum technologies. A critical aspect to realize this potential is to design and control the magnetic exchange. Here, we reveal the effects of frontier orbital symmetries on the magnetic coupling in diradical nanographenes through scanning probe microscope measurements and different levels of theoretical calculations. In these open-shell nanographenes, the exchange energy exhibits a remarkable variation between 20 and 160 meV. Theoretical calculations reveal that frontier orbital symmetries play a key role in affecting the magnetic coupling on such a large scale. Moreover, a triradical nanographene is demonstrated for investigating the magnetic interaction among three unpaired electrons with unequal magnetic exchange, in agreement with Heisenberg spin model calculations. Our results provide insights into both theoretical design and experimental realization of nanographene materials with different exchange interactions through tuning the orbital symmetry, potentially useful for realizing magnetically operable graphene-based nanomaterials.
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Affiliation(s)
- Qingyang Du
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Xuelei Su
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Yufeng Liu
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Yashi Jiang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Can Li
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - KaKing Yan
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China
| | - Ricardo Ortiz
- Donostia International Physics Center (DIPC) - UPV/EHU, 20018, San Sebastián, Spain.
| | - Thomas Frederiksen
- Donostia International Physics Center (DIPC) - UPV/EHU, 20018, San Sebastián, Spain.
- IKERBASQUE, Basque Foundation for Science, 48013, Bilbao, Spain.
| | - Shiyong Wang
- Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Shenyang National Laboratory for Materials Science, School of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai, 200240, China.
- Tsung-Dao Lee Institute, Shanghai Jiao Tong University, Shanghai, 200240, China.
| | - Ping Yu
- School of Physical Science and Technology, ShanghaiTech University, 201210, Shanghai, China.
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18
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Sarkar S, Au-Yeung KH, Kühne T, Waentig A, Ryndyk DA, Heine T, Cuniberti G, Feng X, Moresco F. Adsorption and reversible conformational change of a thiophene based molecule on Au(111). Sci Rep 2023; 13:10627. [PMID: 37391525 DOI: 10.1038/s41598-023-37661-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 06/25/2023] [Indexed: 07/02/2023] Open
Abstract
We present a low temperature scanning tunneling microscope investigation of a prochiral thiophene-based molecule that self-assembles forming islands with different domains on the Au(111) surface. In the domains, two different conformations of the single molecule are observed, depending on a slight rotation of two adjacent bromothiophene groups. Using voltage pulses from the tip, single molecules can be switched between the two conformations. The electronic states have been measured with scanning tunneling spectroscopy, showing that the electronic resonances are mainly localized at the same positions in both conformations. Density-functional theory calculations support the experimental results. Furthermore, we observe that on Ag(111), only one configuration is present and therefore the switching effect is suppressed.
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Affiliation(s)
- Suchetana Sarkar
- Center for Advancing Electronics Dresden, TU Dresden, 01062, Dresden, Germany
| | - Kwan Ho Au-Yeung
- Center for Advancing Electronics Dresden, TU Dresden, 01062, Dresden, Germany
| | - Tim Kühne
- Center for Advancing Electronics Dresden, TU Dresden, 01062, Dresden, Germany
| | - Albrecht Waentig
- Center for Advancing Electronics Dresden, TU Dresden, 01062, Dresden, Germany
- Chair of Molecular Functional Materials and Faculty of Chemistry and Food Chemistry, TU Dresden, 01062, Dresden, Germany
| | - Dmitry A Ryndyk
- Theoretical Chemistry, TU Dresden, 01062, Dresden, Germany
- Institute for Materials Science, TU Dresden, 01062, Dresden, Germany
| | - Thomas Heine
- Theoretical Chemistry, TU Dresden, 01062, Dresden, Germany
| | | | - Xinliang Feng
- Center for Advancing Electronics Dresden, TU Dresden, 01062, Dresden, Germany
- Chair of Molecular Functional Materials and Faculty of Chemistry and Food Chemistry, TU Dresden, 01062, Dresden, Germany
| | - Francesca Moresco
- Center for Advancing Electronics Dresden, TU Dresden, 01062, Dresden, Germany.
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19
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Yu H, Sun J, Heine T. Predicting Magnetic Coupling and Spin-Polarization Energy in Triangulene Analogues. J Chem Theory Comput 2023. [PMID: 37263582 DOI: 10.1021/acs.jctc.3c00175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Triangulene and its analogue metal-free magnetic systems have garnered increasing attention since their discovery. Predicting the magnetic coupling and spin-polarization energy with quantitative accuracy is beyond the predictive power of today's density functional theory (DFT) due to their intrinsic multireference character. Herein, we create a benchmark dataset of 25 magnetic systems with nonlocal spin densities, including the triangulene monomer, dimer, and their analogues. We calculate the magnetic coupling (J) and spin-polarization energy (ΔEspin) of these systems using complete active space self-consistent field (CASSCF) and coupled-cluster methods as high-quality reference values. This reference data is then used to benchmark 22 DFT functionals commonly used in material science. Our results show that, while some functionals consistently correctly predict the qualitative character of the ground state, achieving quantitative accuracy with small relative errors is currently not feasible. PBE0, M06-2X, and MN15 are predicting the correct electronic ground state for all systems investigated here and also have the lowest mean absolute error for predicting both ΔEspin (0.34, 0.32, and 0.31 eV) and J (11.74, 12.66, and 10.64 meV). They may therefore also serve as starting points for higher-level methods such as the GW or the random phase approximation. As other functionals fail for the prediction of the ground state, they cannot be recommended for metal-free magnetic systems.
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Affiliation(s)
- Hongde Yu
- Faculty of Chemistry and Food Chemistry, TU Dresden, 01069 Dresden, Germany
| | - Jianwei Sun
- Department of Physics and Engineering Physics, Tulane University, New Orleans, Louisiana 70118, United States
| | - Thomas Heine
- Faculty of Chemistry and Food Chemistry, TU Dresden, 01069 Dresden, Germany
- Institute of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, 04316 Leipzig, Germany
- Department of Chemistry, Yonsei University and IBS CNM, Seoul 120-749, Korea
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20
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Turco E, Bernhardt A, Krane N, Valenta L, Fasel R, Juríček M, Ruffieux P. Observation of the Magnetic Ground State of the Two Smallest Triangular Nanographenes. JACS AU 2023; 3:1358-1364. [PMID: 37234116 PMCID: PMC10207087 DOI: 10.1021/jacsau.2c00666] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 02/02/2023] [Accepted: 02/02/2023] [Indexed: 05/27/2023]
Abstract
Fusion of three benzene rings in a triangular fashion gives rise to the smallest open-shell graphene fragment, the phenalenyl radical, whose π-extension leads to an entire family of non-Kekulé triangular nanographenes with high-spin ground states. Here, we report the first synthesis of unsubstituted phenalenyl on a Au(111) surface, which is achieved by combining in-solution synthesis of the hydro-precursor and on-surface activation by atomic manipulation, using the tip of a scanning tunneling microscope. Single-molecule structural and electronic characterizations confirm its open-shell S = 1/2 ground state that gives rise to Kondo screening on the Au(111) surface. In addition, we compare the phenalenyl's electronic properties with those of triangulene, the second homologue in the series, whose S = 1 ground state induces an underscreened Kondo effect. Our results set a new lower size limit in the on-surface synthesis of magnetic nanographenes that can serve as building blocks for the realization of new exotic quantum phases of matter.
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Affiliation(s)
- Elia Turco
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Annika Bernhardt
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Nils Krane
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
| | - Leoš Valenta
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Roman Fasel
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
- Department
of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern, 3012 Bern, Switzerland
| | - Michal Juríček
- Department
of Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Pascal Ruffieux
- nanotech@surfaces
Laboratory, Empa−Swiss Federal Laboratories
for Materials Science and Technology, 8600 Dübendorf, Switzerland
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21
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Wang T, Fan Q, Zhu J. Steering On-Surface Reactions by Kinetic and Thermodynamic Strategies. J Phys Chem Lett 2023; 14:2251-2262. [PMID: 36821589 DOI: 10.1021/acs.jpclett.3c00001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
On-surface synthesis has emerged as a powerful tool to fabricate various functional low-dimensional nanostructures with atomic precision, thus becoming a promising platform for the preparation of next-generation semiconductive, magnetic, and topological nanodevices. With the aid of scanning tunneling microscopy/spectroscopy and noncontact atomic force microscopy, both the chemical structures and physical properties of the obtained products can be well characterized. A major challenge in this field is how to efficiently steer reaction pathways and improve the yield/quality of products. To address this problem, in recent years various kinetic and thermodynamic strategies have been successfully employed to control on-surface reactions. In this Perspective, we discuss these strategies in view of basic reaction steps on surfaces, including molecular adsorption, diffusion, and reaction. We hope this Perspective will help readers to deepen the understanding of the mechanisms of on-surface reactions and rationally design reaction procedures for the fabrication of high-quality functional nanomaterials on surfaces.
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Affiliation(s)
- Tao Wang
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
- Donostia International Physics Center, San Sebastián 20018, Spain
| | - Qitang Fan
- Hefei National Research Center for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics, University of Science and Technology of China, Hefei 230026, P. R. China
| | - Junfa Zhu
- Department of Pharmacy, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, and National Synchrotron Radiation Laboratory, University of Science and Technology of China, Hefei 230029, P. R. China
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22
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Lipton-Duffin J, MacLeod J. Innovations in nanosynthesis: emerging techniques for precision, scalability, and spatial control in reactions of organic molecules on solid surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2023; 35:183001. [PMID: 36876935 DOI: 10.1088/1361-648x/acbc01] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/30/2022] [Accepted: 02/13/2023] [Indexed: 06/18/2023]
Abstract
The surface science-based approach to synthesising new organic materials on surfaces has gained considerable attention in recent years, owing to its success in facilitating the formation of novel 0D, 1D and 2D architectures. The primary mechanism used to date has been the catalytic transformation of small organic molecules through substrate-enabled reactions. In this Topical Review, we provide an overview of alternate approaches to controlling molecular reactions on surfaces. These approaches include light, electron and ion-initiated reactions, electrospray ionisation deposition-based techniques, collisions of neutral atoms and molecules, and superhydrogenation. We focus on the opportunities afforded by these alternative approaches, in particular where they may offer advantages in terms of selectivity, spatial control or scalability.
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Affiliation(s)
- Josh Lipton-Duffin
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Australia
- Central Analytical Research Facility, Queensland University of Technology (QUT), Brisbane, Australia
| | - Jennifer MacLeod
- School of Chemistry and Physics and Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, Australia
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23
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Zhang H, Pink M, Wang Y, Rajca S, Rajca A. High-Spin S = 3/2 Ground-State Aminyl Triradicals: Toward High-Spin Oligo-Aza Nanographenes. J Am Chem Soc 2022; 144:19576-19591. [PMID: 36251959 PMCID: PMC10438970 DOI: 10.1021/jacs.2c09241] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report high-spin aminyl triradicals with near-planar triphenylene backbones. Near-planarity of the fused aminyl radicals and the 2,6,10-triphenylene ferromagnetic coupling unit (FCU), magnetically equivalent to three fused 3,4'-biphenyl FCUs, assures an effective 2pπ-2pπ overlap within the cross-conjugated π-system, leading to an S = 3/2 (quartet) ground state that is well separated from low-spin excited doublet states. Thermal populations of the low-spin (S = 1/2) excited states are detectable both by SQUID magnetometry and electron paramagnetic resonance (EPR) spectroscopy, providing doublet-quartet energy gaps, ΔEDQ, corresponding to >85% population of the quartet ground states at room temperature. Notably, EPR-based determination of ΔEDQ relies on direct detection of the quartet ground state and doublet excited states. The ΔEDQ values are 1.0-1.1 kcal mol-1, with the more sterically shielded triradical having the larger value. The half-life of the more sterically shielded triradical in 2-methyltetrahydrofuran (2-MeTHF) is about 6 h at room temperature. The less sterically shielded triradical in 2-MeTHF decomposes at 158 K with a half-life of about 4 h, while at 195 K, the half-life is still about 2 h. The dominant products of the decay of triradicals are the corresponding triamines, suggesting hydrogen atom abstraction from the solvent as the primary mechanism. This study expands the frontier of the open-shell PAHs/nanographenes, of which the unique electronic, nonlinear optical, and magnetic properties could be useful in the development of novel organic electronics, photonics, and spintronics.
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Affiliation(s)
- Hui Zhang
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, United States
| | - Maren Pink
- IUMSC, Department of Chemistry, Indiana University, Bloomington, IN 47405-7102, United States
| | - Ying Wang
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, United States
| | - Suchada Rajca
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, United States
| | - Andrzej Rajca
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588-0304, United States
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24
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Wei H, Hou X, Xu T, Zou Y, Li G, Wu S, Geng Y, Wu J. Solution‐Phase Synthesis and Isolation of An Aza‐Triangulene and Its Cation in Crystalline Form. Angew Chem Int Ed Engl 2022; 61:e202210386. [DOI: 10.1002/anie.202210386] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Indexed: 11/07/2022]
Affiliation(s)
- Haipeng Wei
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
| | - Xudong Hou
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Tingting Xu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Ya Zou
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Guangwu Li
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Shaofei Wu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
| | - Yanhou Geng
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
| | - Jishan Wu
- Department of Chemistry National University of Singapore 3 Science Drive 3 Singapore 117543 Singapore
- Joint School of National University of Singapore and Tianjin University International Campus of Tianjin University Binhai New City Fuzhou 350207 China
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25
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Friedrich N, Menchón RE, Pozo I, Hieulle J, Vegliante A, Li J, Sánchez-Portal D, Peña D, Garcia-Lekue A, Pascual JI. Addressing Electron Spins Embedded in Metallic Graphene Nanoribbons. ACS NANO 2022; 16:14819-14826. [PMID: 36037149 PMCID: PMC9527809 DOI: 10.1021/acsnano.2c05673] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Spin-hosting graphene nanostructures are promising metal-free systems for elementary quantum spintronic devices. Conventionally, spins are protected from quenching by electronic band gaps, which also hinder electronic access to their quantum state. Here, we present a narrow graphene nanoribbon substitutionally doped with boron heteroatoms that combines a metallic character with the presence of localized spin 1/2 states in its interior. The ribbon was fabricated by on-surface synthesis on a Au(111) substrate. Transport measurements through ribbons suspended between the tip and the sample of a scanning tunneling microscope revealed their ballistic behavior, characteristic of metallic nanowires. Conductance spectra show fingerprints of localized spin states in the form of Kondo resonances and inelastic tunneling excitations. Density functional theory rationalizes the metallic character of the graphene nanoribbon due to the partial depopulation of the valence band induced by the boron atoms. The transferred charge builds localized magnetic moments around the boron atoms. The orthogonal symmetry of the spin-hosting state's and the valence band's wave functions protects them from mixing, maintaining the spin states localized. The combination of ballistic transport and spin localization into a single graphene nanoribbon offers the perspective of electronically addressing and controlling carbon spins in real device architectures.
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Affiliation(s)
| | - Rodrigo E. Menchón
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
| | - Iago Pozo
- CiQUS,
Centro Singular de Investigación en Química Biolóxica
e Materiais Moleculares, 15705 Santiago de Compostela, Spain
| | | | | | - Jingcheng Li
- CIC
nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
| | - Daniel Sánchez-Portal
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Centro
de Física de Materiales CSIC-UPV/EHU, 20018 Donostia-San Sebastián, Spain
| | - Diego Peña
- CiQUS,
Centro Singular de Investigación en Química Biolóxica
e Materiais Moleculares, 15705 Santiago de Compostela, Spain
| | - Aran Garcia-Lekue
- Donostia
International Physics Center (DIPC), 20018 Donostia-San Sebastián, Spain
- Ikerbasque,
Basque Foundation for Science, 48013 Bilbao, Spain
| | - José Ignacio Pascual
- CIC
nanoGUNE-BRTA, 20018 Donostia-San Sebastián, Spain
- Ikerbasque,
Basque Foundation for Science, 48013 Bilbao, Spain
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26
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de Oteyza DG, Frederiksen T. Carbon-based nanostructures as a versatile platform for tunable π-magnetism. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2022; 34:443001. [PMID: 35977474 DOI: 10.1088/1361-648x/ac8a7f] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
Emergence ofπ-magnetism in open-shell nanographenes has been theoretically predicted decades ago but their experimental characterization was elusive due to the strong chemical reactivity that makes their synthesis and stabilization difficult. In recent years, on-surface synthesis under vacuum conditions has provided unprecedented opportunities for atomically precise engineering of nanographenes, which in combination with scanning probe techniques have led to a substantial progress in our capabilities to realize localized electron spin states and to control electron spin interactions at the atomic scale. Here we review the essential concepts and the remarkable advances in the last few years, and outline the versatility of carbon-basedπ-magnetic materials as an interesting platform for applications in spintronics and quantum technologies.
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Affiliation(s)
- Dimas G de Oteyza
- Nanomaterials and Nanotechnology Research Center (CINN), CSIC-UNIOVI-PA, E-33940 El Entrego, Spain
- Donostia International Physics Center (DIPC)-UPV/EHU, E-20018 San Sebastián, Spain
| | - Thomas Frederiksen
- Donostia International Physics Center (DIPC)-UPV/EHU, E-20018 San Sebastián, Spain
- Ikerbasque, Basque Foundation for Science, E-48013 Bilbao, Spain
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27
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Wei H, Hou X, Xu T, Zou Y, Li G, Wu S, Geng Y, Wu J. Solution‐Phase Synthesis and Isolation of An Aza‐Triangulene and Its Cation in Crystalline Form. Angew Chem Int Ed Engl 2022. [DOI: 10.1002/ange.202210386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Haipeng Wei
- National University of Singapore Chemistry SINGAPORE
| | - Xudong Hou
- National University of Singapore Chemistry SINGAPORE
| | - Tingting Xu
- National University of Singapore Chemistry SINGAPORE
| | - Ya Zou
- National University of Singapore Chemistry SINGAPORE
| | - Guangwu Li
- National University of Singapore Chemistry SINGAPORE
| | - Shaofei Wu
- National University of Singapore Chemistry SINGAPORE
| | - Yanhou Geng
- National University of Singapore Chemistry SINGAPORE
| | - Jishan Wu
- National University of Singapore Chemistry 3 Science Drive 3 117543 Singapore SINGAPORE
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28
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Yang XQ, Duan JJ, Su J, Peng X, Yi ZY, Li RN, Lu J, Wang SF, Chen T, Wang D. Aromatic Ring Fusion to Benzoporphyrin via γ- ortho Cyclodehydrogenation on a Ag(111) Surface. ACS NANO 2022; 16:13092-13100. [PMID: 35913404 DOI: 10.1021/acsnano.2c05819] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Aromatic ring fusion to porphyrins and their derivatives represents an attractive route to tune the molecular conjugation and thus expand their functionalities. Here, we report the expansion of the aromatic π-system of palladium tetraphenyltetrabenzoporphyrins (Pd-TPTBP) via surface-assisted γ-ortho cyclodehydrogenation on Ag(111). The chemical transformation of Pd-TPTBP into different products at an elevated temperature of 600 K was revealed at the single-molecule level using bond-resolved scanning tunneling microscopy with a CO-functionalized tip. We captured a series of γ-ortho cyclodehydrogenation products, wherein the maximum extent to which the reaction can progress is associated with 7-fold C-C formation to afford nearly planar γ-ortho fused porphyrins with 66 conjugated π-electrons. In addition, a small number of molecules undergo C-C bond dissociation of meso-phenyl at elevated temperature, producing fully planar γ-ortho fused products lacking one or two phenyl moieties. Scanning tunneling spectroscopy measurements and DFT calculations suggest the electronic gap of the γ-ortho fused porphyrin decreases compared to that of the precursor. The HOMO and LUMO of the planar γ-ortho fused products are localized on the partially fused benzo moieties and the meso-position, respectively.
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Affiliation(s)
- Xue-Qing Yang
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, People's Republic of China
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, People's Republic of China
| | - Jun-Jie Duan
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Jie Su
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Xinnan Peng
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
| | - Zhen-Yu Yi
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Ruo-Ning Li
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, People's Republic of China
| | - Jiong Lu
- Department of Chemistry, National University of Singapore, 3 Science Drive 3, Singapore 117543, Singapore
- Institute for Functional Intelligent Materials, National University of Singapore, Singapore 117544, Singapore
| | - Sheng-Fu Wang
- Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules, College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062, People's Republic of China
| | - Ting Chen
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, People's Republic of China
| | - Dong Wang
- Key Laboratory of Molecular Nanostructure and Nanotechnology and Beijing National Laboratory for Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences (CAS), Beijing 100190, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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29
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Yang CC, Zheng XL, Chen J, Tian WQ, Li WQ, Yang L. Spin engineering of triangulenes and application for nano nonlinear optical materials design. Phys Chem Chem Phys 2022; 24:18529-18542. [PMID: 35899847 DOI: 10.1039/d2cp02915d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The recently synthesized triangulenes with non-bonding edge states could have broad potential applications in magnetics, spintronics and electro-optics if they have appropriate electronic structure modulation. In the present work, strategies based on molecular orbital theory through heteroatom doping are proposed to redistribute, reduce or eliminate the spin of triangulenes for novel functional materials design, and the role of B, N, NBN, and BNB in such intended electronic structure manipulation is scrutinized. π-Extended triangulenes with tunable electronic properties could be potential nonlinear optical (NLO) materials with appropriate inhibition of their polyradical nature. The elimination of spin is achieved by B, N, NBN, and BNB doping with the intended geometric arrangement for enhanced polarity. Intended doping of BNB results in an optimal structure with large static first hyperpolarizability (〈β0〉) as well as strong Hyper-Rayleigh scattering (HRS) βHRS(-2ω; ω, ω) (ω = 1064.0 nm), TG7-BNB-ba with a large 〈β0〉 (18.85 × 10-30 esu per heavy atom) and βHRS (1.15 × 10-28 esu per heavy atom) much larger than that of a synthesized triangular molecule (1.12 × 10-30 esu of 〈β0〉 per heavy atom and 5.04 × 10-30 esu of βHRS per heavy atom). The strong second order NLO responses in the near-infrared and visible regions, particularly the strong sum frequency generation, make these B or (and) N doped triangulenes promising candidates for the fabrication of novel carbon-based optoelectronic devices and micro-NLO devices.
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Affiliation(s)
- Cui-Cui Yang
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Huxi Campus, Chongqing 401331, China.
| | - Xue-Lian Zheng
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Huxi Campus, Chongqing 401331, China.
| | - Jiu Chen
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Huxi Campus, Chongqing 401331, China.
| | - Wei Quan Tian
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, College of Chemistry and Chemical Engineering, Chongqing University, Huxi Campus, Chongqing 401331, China.
| | - Wei-Qi Li
- Department of Physics, Harbin Institute of Technology, Harbin 150001, China.,Technology Innovation Center of Materials and Devices at Extreme Environment, School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China. .,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan 030006, P. R. China
| | - Ling Yang
- Wenzhou Institute, University of Chinese Academy of Sciences, 1 Jinlian Street, Wenzhou 325001, China.
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30
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Wen ECH, Jacobse PH, Jiang J, Wang Z, McCurdy RD, Louie SG, Crommie MF, Fischer FR. Magnetic Interactions in Substitutional Core-Doped Graphene Nanoribbons. J Am Chem Soc 2022; 144:13696-13703. [PMID: 35867847 DOI: 10.1021/jacs.2c04432] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The design of a spin imbalance within the crystallographic unit cell of bottom-up engineered 1D graphene nanoribbons (GNRs) gives rise to nonzero magnetic moments within each cell. Here, we demonstrate the bottom-up assembly and spectroscopic characterization of a one-dimensional Kondo spin chain formed by a chevron-type GNR (cGNR) physisorbed on Au(111). Substitutional nitrogen core doping introduces a pair of low-lying occupied states per monomer within the semiconducting gap of cGNRs. Charging resulting from the interaction with the gold substrate quenches one electronic state for each monomer, leaving behind a 1D chain of radical cations commensurate with the unit cell of the ribbon. Scanning tunneling microscopy (STM) and spectroscopy (STS) reveal the signature of a Kondo resonance emerging from the interaction of S = 1/2 spin centers in each monomer core with itinerant electrons in the Au substrate. STM tip lift-off experiments locally reduce the effective screening of the unpaired radical cation being lifted, revealing a robust exchange coupling between neighboring spin centers. First-principles DFT-LSDA calculations support the presence of magnetic moments in the core of this GNR when it is placed on Au.
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Affiliation(s)
- Ethan Chi Ho Wen
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Peter H Jacobse
- Department of Physics, University of California, Berkeley, California 94720, United States
| | - Jingwei Jiang
- Department of Physics, University of California, Berkeley, California 94720, United States.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Ziyi Wang
- Department of Physics, University of California, Berkeley, California 94720, United States
| | - Ryan D McCurdy
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Steven G Louie
- Department of Physics, University of California, Berkeley, California 94720, United States.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Michael F Crommie
- Department of Physics, University of California, Berkeley, California 94720, United States.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Kavli Energy NanoSciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
| | - Felix R Fischer
- Department of Chemistry, University of California, Berkeley, California 94720, United States.,Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.,Kavli Energy NanoSciences Institute at the University of California Berkeley and the Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
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31
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Zhang Y, Lu J, Li B, Chen W, Xiong W, Ruan Z, Zhang H, Sun S, Chen L, Gao L, Cai J. On-surface synthesis and characterization of nitrogen-doped covalent-organic frameworks on Ag(111) substrate. J Chem Phys 2022; 157:031103. [DOI: 10.1063/5.0099995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Atomically precise fabrication of covalent-organic frameworks with well-defined heteroatom-dopant sites and further understanding of their electronic properties at the atomic level remain a challenge. Herein, we demonstrate the bottom-up synthesis of well-organized covalent-organic frameworks doped by nitrogen atoms on an Ag(111) substrate. Using high-resolution scanning tunneling microscopy and non-contact atomic force microscopy, the atomic structures of the intermediate metal–organic frameworks and the final covalent-organic frameworks are clearly identified. Scanning tunneling spectroscopy characterization reveals that the electronic bandgap of the as-formed N-doped covalent-organic framework is 2.45 eV, in qualitative agreement with the theoretical calculations. The calculated band structure together with the projected density of states analysis clearly unveils that the incorporation of nitrogen atoms into the covalent-organic framework backbone will remarkably tune the bandgap owing to the fact that the foreign nitrogen atom has one more electron than the carbon atom. Such covalent-organic frameworks may offer an atomic-scale understanding of the local electronic structure of heteroatom-doped covalent-organic frameworks and hold great promise for all relevant wide bandgap semiconductor technologies, for example, electronics, photonics, high-power and high-frequency devices, and solar energy conversion.
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Affiliation(s)
- Yong Zhang
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Jianchen Lu
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Baijin Li
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Weiben Chen
- College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen 518060, China
| | - Wei Xiong
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Zilin Ruan
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Hui Zhang
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Shijie Sun
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
| | - Long Chen
- State Key Laboratory of Supramolecular Structure and Materials, College of Chemistry, Jilin University, Changchun 130012, China
| | - Lei Gao
- Faculty of Science, Kunming University of Science and Technology, No. 727 Jingming South Road, Kunming 650500, China
| | - Jinming Cai
- Faculty of Materials Science and Engineering, Kunming University of Science and Technology, No. 68 Wenchang Road, Kunming 650093, China
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32
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Alcón I, Calogero G, Papior N, Antidormi A, Song K, Cummings AW, Brandbyge M, Roche S. Unveiling the Multiradical Character of the Biphenylene Network and Its Anisotropic Charge Transport. J Am Chem Soc 2022; 144:8278-8285. [PMID: 35476458 PMCID: PMC9100647 DOI: 10.1021/jacs.2c02178] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Recent progress in the on-surface synthesis and characterization of nanomaterials is facilitating the realization of new carbon allotropes, such as nanoporous graphenes, graphynes, and 2D π-conjugated polymers. One of the latest examples is the biphenylene network (BPN), which was recently fabricated on gold and characterized with atomic precision. This gapless 2D organic material presents uncommon metallic conduction, which could help develop innovative carbon-based electronics. Here, using first principles calculations and quantum transport simulations, we provide new insights into some fundamental properties of BPN, which are key for its further technological exploitation. We predict that BPN hosts an unprecedented spin-polarized multiradical ground state, which has important implications for the chemical reactivity of the 2D material under practical use conditions. The associated electronic band gap is highly sensitive to perturbations, as seen in finite temperature (300 K) molecular dynamics simulations, but the multiradical character remains stable. Furthermore, BPN is found to host in-plane anisotropic (spin-polarized) electrical transport, rooted in its intrinsic structural features, which suggests potential device functionality of interest for both nanoelectronics and spintronics.
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Affiliation(s)
- Isaac Alcón
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona 08193, Spain.,Institut für Chemie und Biochemie, Physikalische und Theoretische Chemie, Freie Universität Berlin, Arnimallee 22, Berlin 14195, Germany
| | - Gaetano Calogero
- CNR Institute for Microelectronics and Microsystems (CNR-IMM), Zona Industriale, Strada VIII, 5, Catania 95121, Italy
| | - Nick Papior
- Computing Center, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark
| | - Aleandro Antidormi
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona 08193, Spain
| | - Kenan Song
- Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), Thuwal 23955, Saudi Arabia
| | - Aron W Cummings
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona 08193, Spain
| | - Mads Brandbyge
- Department of Physics, Technical University of Denmark, Kongens Lyngby DK-2800, Denmark.,Center for Nanostructured Graphene (CNG), Kongens Lyngby DK-2800, Denmark
| | - Stephan Roche
- Catalan Institute of Nanoscience and Nanotechnology (ICN2), CSIC and BIST, Campus UAB, Bellaterra, Barcelona 08193, Spain.,ICREA-Institució Catalana de Recerca i Estudis Avançats, Barcelona 08070, Spain
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