Exploration of Heteroaromatic and Antiaromatic Atomically Precise Nanographenes

• Applicant: Professor Dr. Xinliang Feng
• Subject Area: Preparatory and Physical Chemistry of Polymers ; Polymer Materials
• Term: from 2018 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 391979941

• Final Report Year: 2021

Final Report Abstract

Since its first isolation in 2004, graphene has attracted enormous attention due to its exceptional electronic, optical and mechanical properties. Although graphene shows extremely high charge carrier mobility, the lack of band gap in graphene limits its applications in most electronic devices. As a result of quantum confinement, the structurally confined nanoscale graphene fragments, namely, nanographenes (NGs) and graphene nanoribbons (GNRs), show non-zero band gaps, which are attractive for nextgeneration semiconductor applications. Recent experimental and theoretical studies implied that the electronic structure and physicochemical properties of NGs and GNRs are largely governed by their size, topology and edge structures. Moreover, hetero-atom doing in NGs and GNRs was emerged as a powerful method to tune their optical, electronic and magnetic properties. Such properties are highly dependent not only on the heteroatom type (i.e., sulfur, nitrogen, or boron) but also on the doping position and concentration. For example, we firstly achieved the dimerization of polycyclic aromatic azomethine ylide (PAMY) on surfaces and further proved that thermally induced dehydrogenation can produce fully cyclized pyrazine-embedded antiaromatic hexaperi-hexabenzocoronene. However, the heteroatom doping in NGs and GNRs remains elusive due to the limited synthetic strategies. In this joint Sino-German proposal, we have brought together the TU Dresden (TUD), a leader in synthetic carbon nanostructures, and leaders in fundamental and applied surface science at the Institute of Physics of the Chinese Academy of Sciences (IoPCAS), to establish a new field of research in heteroatom-doped cove-edged and isoelectronic zigzag-edged, as well as antiaromatic nanographene science. The IoPCAS is known for having the largest availability of UHV surface science equipment worldwide. Within this project period, different classes of heteroatom-doped NGs and GNRs were synthesized with the combination of in-solution and on-surface chemistry, including the S-doped GNRs, S-doped helical NGs, N-doped NGs and GNRs, as well as the NBN-doped peri-acenes and zigzag-edged GNRs, etc. Moreover, we also found several interesting reactions, such as the 1,4-boron migration toward B-doped NGs, the force-activated reversible isomerization of a single molecule, and the selective hierarchical C-H bond activation on surface. Overall, this proposal has stimulated the mobility of researchers between both countries within this key and strategic field of research, which opened up a new research direction in the nanographene chemistry.

Publications

• Tailoring Bond Topologies in Open-Shell Graphene Nanostructures, ACS Nano 2018, 12, 11917-11927
  S. Mishra, T. Lohr, C. Pignedoli, J. Liu, R. Berger, J. Urgel, K. Müllen, X. Feng, P. Ruffieux, R. Fasel
  
• Tuning the morphology of chevron-type graphene nanoribbons by choice of annealing temperature. Nano Res. 2018, 11, 6190-6196
  Y. Cao, J. Qi, Y.-F. Zhang, L. Huang, Q. Zheng, X. Lin, Z. Cheng, Y.-Y. Zhang, X. Feng, S. Du
  
• NBN-embedded polycyclic aromatic hydrocarbons containing pentagonal and heptagonal rings. Org. Lett. 2019, 21, 1354-1358
  Y. Fu, K. Zhang, E. Dmitrieva, F. Liu, J. Ma, J. J. Weigand, A. A. Popov, R. Berger, W. Pisula, J. Liu
  
• Polycyclic Aromatic Hydrocarbons Containing a Pyrrolopyridazine Core, Chempluschem 2019, 84, 613-618
  M. Richter, Y. Fu, E. Dmitrieva, J. Weigand, A. Popov, R. Berger, J. Liu, X. Feng
  
• Force-activated isomerization of a single molecule. J. Am. Chem. Soc. 2020, 142, 10673-10680
  J. Qi, Y. Gao, H. Jia, M. Richter, L. Huang, Y. Cao, H. Yang, Q. Zheng, R. Berger, J. Liu, X. Lin, H. Lu, Z. Cheng, M. Ouyang, X. Feng, S. Du, H. Gao
  
• On-Surface Synthesis of NBN-Doped Zigzag-Edged Graphene Nanoribbons. Angew. Chem. Int. Ed. 2020, 59 (23), 8873-8879
  Y. Fu, H. Yang, Y. Gao, L. Huang, R. Berger, J. Liu, H. Lu, Z. Cheng, S. Du, H. J. Gao
  
• Polycyclic aromatic chains on metals and insulating layers by repetitive [3+ 2] cycloadditions. Nat. Commun. 2020, 11, 1490-1497
  A. Riss, M. Richter, A. P. r. Paz, X.-Y. Wang, R. Raju, Y. He, J. Ducke, E. Corral, M. Wuttke, K. Seufert, M. Garnica, A. Rubio, J. V. Barth, A. Narita, K. Müllen, R. Berger, X.Feng, C. Palma, W. Auwärter
  
• A Modular Cascade Synthetic Strategy Toward Structurally Constrained Boron-doped Polycyclic Aromatic Hydrocarbons. Angew. Chem. Int. Ed. 2021
  J. J. Zhang, L. Yang, F. Liu, Y. Fu, J. Liu, A. A. Popov, J. Ma, X. Feng
  
• Fabrication of sulfur-doped cove-edged graphene nanoribbons on Au (111). Chin. Phy. B 2021, 30, 077306
  H. Yang, Y. Gao, W. Niu, X. Chang, L. Huang, J. Liu, Y. Mai, X. Feng, S. Du, H.-J. Gao
  
• NBN-Doped Bis-Tetracene and Peri-Tetracene: Synthesis and Characterization. Angew. Chem. Int. Ed. 2021
  Y. Fu, X. Chang, H. Yang, E. Dmitrieva, Y. Gao, J. Ma, L. Huang, J. Liu, H. Lu, Z. Cheng
  
• NBN-doped nanographene embedded with five-and seven-membered rings on Au (111) surface. Chin. Phy. B 2021, 30, 056802
  H. Yang, Y. Cao, Y. Gao, Y. Fu, L. Huang, J. Liu, X. Feng, S. Du, H.-J. Gao
  
• One-Pot Synthesis of Boron-Doped Polycyclic Aromatic Hydrocarbons via 1, 4-Boron Migration. Angew. Chem. Int. Ed. 2021, 60, 2833-2838
  J. J. Zhang, M. C. Tang, Y. Fu, K. H. Low, J. Ma, L. Yang, J. J. Weigand, J. Liu, V. W. W. Yam, X. Feng
  
• One-Pot Synthesis of Boron-Doped Polycyclic Aromatic Hydrocarbons via 1, 4-Boron Migration. Angew. Chem. Int. Ed. 2021, 60, 2833-2838
  J. J. Zhang, M. C. Tang, Y. Fu, K. H. Low, J. Ma, L. Yang, J. J. Weigand, J. Liu, V. W. W. Yam, X. Feng
  
• Sulfur-Doped Nanographenes Containing Multiple Subhelicenes. Org. Lett. 2021, 23, 2069-2073
  W. Niu, Y. Fu, H. Komber, J. Ma, X. Feng, Y. Mai, J. Liu
  
• Synthesis and Self-Assembly Behavior of Double Ullazine- Based Polycyclic Aromatic Hydrocarbons. Org. Mater. 2021, 3, 198-203
  M. Richter, M. Borkowski, Y. Fu, E. Dmitrieva, A. A. Popov, J. Ma, T. Marszalek, W. Pisula, X. Feng