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Qin L, Xie J, Wu B, Hong H, Yang S, Ma Z, Li C, Zhang G, Zhang XS, Liu K, Zhang D. Axially Chiral Nonbenzenoid Nanographene with Second Harmonic Generation Property. J Am Chem Soc 2024; 146:12206-12214. [PMID: 38637324 DOI: 10.1021/jacs.4c03007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/20/2024]
Abstract
Chiral nanographenes (NGs) have garnered significant interest as optoelectronic materials in recent years. While helically chiral NGs have been extensively studied, axially chiral NGs have only witnessed limited examples, with no prior reports of axially chiral nonbenzenoid NGs. Herein we report an axially chiral nonbenzenoid nanographene featuring six pentagons and four heptagons. This compound, denoted as 2, was efficiently synthesized via an efficient Pd-catalyzed aryl silane homocoupling reaction. The presence of two bulky 3,5-di-tert-butylphenyl groups around the axis connecting the two nonbenzenoid PAH (AHR) segments endows 2 with atropisomeric chirality and high racemization energy barrier, effectively preventing racemization of both R- and S-enantiomers at room temperature. Optically pure R-2 and S-2 were obtained by chiral HPLC separation, and they exhibit circular dichroism (CD) activity at wavelengths up to 660 nm, one of the longest wavelengths with CD responses reported for the chiral NGs. Interestingly, racemic 2 forms a homoconfiguration π-dimer in the crystal lattice, belonging to the I222 chiral space group. Consequently, this unique structure renders crystals of 2 with a second harmonic generation (SHG) response, distinguishing it from all the reported axially chiral benzenoid NGs. Moreover, R-2 and S-2 also exhibit SHG-CD properties.
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Affiliation(s)
- Liyuan Qin
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Jin Xie
- School of Physics, Peking University, Beijing 100871, P. R. China
| | - Botao Wu
- College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
| | - Hao Hong
- School of Physics, Peking University, Beijing 100871, P. R. China
| | - Suyu Yang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Zhuangzhuang Ma
- College of Chemistry, Green Catalysis Center, Zhengzhou University, Zhengzhou, Henan 450000, P. R. China
| | - Cheng Li
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Guanxin Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
| | - Xi-Sha Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
| | - Kaihui Liu
- School of Physics, Peking University, Beijing 100871, P. R. China
| | - Deqing Zhang
- Beijing National Laboratory for Molecular Sciences, CAS Key Laboratory of Organic Solids, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
- University of Chinese Academy of Sciences, Beijing 100049, P. R. China
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Biswas K, Chen Q, Obermann S, Ma J, Soler-Polo D, Melidonie J, Barragán A, Sánchez-Grande A, Lauwaet K, Gallego JM, Miranda R, Écija D, Jelínek P, Feng X, Urgel JI. On-Surface Synthesis of Non-Benzenoid Nanographenes Embedding Azulene and Stone-Wales Topologies. Angew Chem Int Ed Engl 2024; 63:e202318185. [PMID: 38299925 DOI: 10.1002/anie.202318185] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/26/2024] [Accepted: 01/30/2024] [Indexed: 02/02/2024]
Abstract
The incorporation of non-benzenoid motifs in graphene nanostructures significantly impacts their properties, making them attractive for applications in carbon-based electronics. However, understanding how specific non-benzenoid structures influence their properties remains limited, and further investigations are needed to fully comprehend their implications. Here, we report an on-surface synthetic strategy toward fabricating non-benzenoid nanographenes containing different combinations of pentagonal and heptagonal rings. Their structure and electronic properties were investigated via scanning tunneling microscopy and spectroscopy, complemented by computational investigations. After thermal activation of the precursor P on the Au(111) surface, we detected two major nanographene products. Nanographene Aa-a embeds two azulene units formed through oxidative ring-closure of methyl substituents, while Aa-s contains one azulene unit and one Stone-Wales defect, formed by the combination of oxidative ring-closure and skeletal ring-rearrangement reactions. Aa-a exhibits an antiferromagnetic ground state with the highest magnetic exchange coupling reported up to date for a non-benzenoid containing nanographene, coexisting with side-products with closed shell configurations resulted from the combination of ring-closure and ring-rearragement reactions (Ba-a , Ba-s , Bs-a and Bs-s ). Our results provide insights into the single gold atom assisted synthesis of novel NGs containing non-benzenoid motifs and their tailored electronic/magnetic properties.
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Affiliation(s)
- Kalyan Biswas
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Qifan Chen
- Institute of Physics of the Czech Academy of Science, CZ-16253, Praha, Czech Republic
- Faculty of Mathematics and Physics, Charles University, V Holešovičkách 2, 180 00, Praha, Czech Republic
| | - Sebastian Obermann
- Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, D-01069, Dresden, Germany
| | - Ji Ma
- Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, D-01069, Dresden, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany
| | - Diego Soler-Polo
- Institute of Physics of the Czech Academy of Science, CZ-16253, Praha, Czech Republic
| | - Jason Melidonie
- Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, D-01069, Dresden, Germany
| | - Ana Barragán
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Ana Sánchez-Grande
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
| | - Koen Lauwaet
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
| | - José M Gallego
- Instituto de Ciencia de Materiales de Madrid (ICMM), CSIC, Cantoblanco, 28049, Madrid, Spain
| | - Rodolfo Miranda
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
- Departamento de Física de la Materia Condensada, Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - David Écija
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
- Unidad de Nanomateriales avanzados, IMDEA Nanoscience, Unidad asociada al CSIC por el ICMM, 28049, Madrid, Spain
| | - Pavel Jelínek
- Institute of Physics of the Czech Academy of Science, CZ-16253, Praha, Czech Republic
- Regional Centre of Advanced Technologies and Materials, Palacký University Olomouc, 771 46, Olomouc, Czech Republic
| | - Xinliang Feng
- Center for Advancing Electronics Dresden (cfaed) & Faculty of Chemistry and Food Chemistry, Technische Universität Dresden, D-01069, Dresden, Germany
- Max Planck Institute of Microstructure Physics, Weinberg 2, 06120, Halle, Germany
| | - José I Urgel
- IMDEA Nanoscience, C/Faraday 9, Campus de Cantoblanco, 28049, Madrid, Spain
- Unidad de Nanomateriales avanzados, IMDEA Nanoscience, Unidad asociada al CSIC por el ICMM, 28049, Madrid, Spain
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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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Liu B, Chen M, Liu X, Fu R, Zhao Y, Duan Y, Zhang L. Bespoke Tailoring of Graphenoid Sheets: A Rippled Molecular Carbon Comprising Cyclically Fused Nonbenzenoid Rings. J Am Chem Soc 2023; 145:28137-28145. [PMID: 38095317 DOI: 10.1021/jacs.3c10303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2023]
Abstract
The incorporation of nonbenzenoid rings into the hexagonal networks of graphenoid nanostructures is of immense importance for electronic, magnetic, and mechanical properties, but the underlying mechanisms of nonbenzenoid ring fusion are rather unexplored. Here, we report the synthesis and characterization of a rippled C84 molecular carbon, which contains 10 nonbenzenoid rings (five-, seven-, and eight-membered rings) that are contiguously fused to give a cyclic geometry. The fused nonbenzenoid rings impart high solubility, configurational stability, multiple reversible redox behaviors, unique aromaticity, and a narrow band gap to the system. Moreover, this carbon nanostructure allows for further functionalization via electrophilic substitution and metalation reactions, enabling access to finely tuned derivatives. Interestingly, both the bowl-shaped and planar conformations of the core in molecular carbon are observed in the solid state. Additionally, this molecular carbon displays ambipolar transport characteristics.
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Affiliation(s)
- Binbin Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Meng Chen
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Xinyue Liu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Ruihua Fu
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yubo Zhao
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Yuxiao Duan
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
| | - Lei Zhang
- Beijing Advanced Innovation Center for Soft Matter Science and Engineering, State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029, China
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