FY2020 Annual Report

Organic and Carbon Nanomaterials Unit
Assistant Professor Akimitsu Narita


The unit is pursuing the synthesis of carbon nanomaterials with atomically precise structures, elucidation of their properties, and exploration of their applications. FY2020 was the third year of the unit, but the first year of operation physically at OIST after the opening of Lab4 in April 2020. Although the planned relocation of many of the unit members and start of the experiments were largely delayed due to the COVID-19, establishment of the laboratory has been mostly completed and the unit has welcomed Dr. Zakaria Ziadi (Staff Scientist), Dr. Goudappagouda (Postdoctoral Scholar), and Mr. Saurav Raj (Special Research Student), and hosted two OIST rotation students, Mr. Kuan-Lin Chen and Mr. Qizheng Zhang. Dr. Jingyun Tan and Dr. Hao Zhao have also joined the unit as Researcher (External) while waiting for their relocations. We have mainly worked on the synthesis of novel nanocarbon molecules with intriguing optical properties as well as exploration of new on-surface synthetic methods towards fabrication of atomically precise graphene nanoribbons (GNRs) on metal surfaces. We have commenced the JSPS KAKENHI project (Returning Researcher Development Research; 19K24686) in October 2020, which aims at the synthesis of helical nanographenes and graphene nanosolenoids, and also joined a EU project "LIGHT-CAP" as an extra-EU partner.

1. Staff

  • Dr. Zakaria Ziadi, Staff Scientist 
  • Dr. Xiushang Xu, Postdoctoral Scholar
  • Dr. Goudappagouda, Postdoctoral Scholar
  • Dr. Jingyun Tan, Researcher (External)
  • Dr. Hao Zhao, Researcher (External)
  • Mr. Saurav Raj, Special Research Student  
  • Mr. Kuan-Lin Chen, OIST Rotation Student (Jan.2021-Apr.2021)
  • Mr. Qizheng Zhang, OIST Rotation Student (Jan.2021-Apr.2021)
  • Ms. Ayumi Shimojima, Research Unit Administrator

2. Collaborations

2.1 Synthesis and Characterizations of Functional Polycyclic Aromatic Hydrocarbons and Atomically Precise Graphene Nanoribbons

  • Type of collaboration: Joint research
  • Researchers:
    • Professor Klaus Müllen, Max Planck Institute for Polymer Research, Mainz, Germany
    • Professor Roman Fasel, nanotech@surfaces laboratory, Empa – Swiss Federal Laboratories for Materials Science and Technology, Dübendorf, Switzerland
    • Professor Xinliang Feng, Faculty of Chemistry and Food Chemistry and Center for Advancing Electronics Dresden, Technical University of Dresden, Germany
    • Associate Professor Yunbin Hu, College of Chemistry and Chemical Engineering, Central South University, Changsha, China
    • Dr. Marco Di Giovannantonio, Consiglio Nazionale delle Ricerche (CNR), Istituto di Struttura della Materia (ISM), Roma, Italy

2.2 Investigations of Photoluminescence Properties of Carbon Nanomaterials 

  • Type of collaboration: Joint research
  • Researchers:
    • Professor Jean-Sébastien Lauret, Ecole Normale Supérieure de Paris Saclay, Orsay cedex, France
    • Dr. Stéphane Campidelli, CEA-Saclay, Gif sur Yvette, France

3. Activities and Findings

3.1 Synthesis and Characterizations of Large Polycyclic Aromatic Hydrocarbons as Atomically Precise Graphene Quantum Dots and Their Functionalization

Graphene quantum dots (GQDs) can serve as carbon-based fluorescent materials that are heavy-metal free and environmentally friendly, providing an alternative for semiconductor quantum dots. However, GQDs prepared by conventional methods typically have non-uniform and uncontrallable chemical structures, making it difficult to selectively obtain desired properties. In contrast, the methods of synthetic organic chemistry allows for fabrication of GQDs with atomically precise chemical structures, which are in principle equivalent to large polycyclic hydrocarbons (PAHs). Recently, a novel PAH, dibenzo[hi,st]ovalene (DBOV) has demonstrated very strong red emission and high thermal and photo stability, with properties virtually at the interface of organic dyes and semiconductor quantum dots (cf. publication 1 in 4.1.3 below). These features make DBOV derivatives particularly interesting for light-emitting device and bioimaging applications. For the latter, we have been working on syntheses of functionalized, water-soluble DBOVs that is capable of bioconjugation, and the first set of samples for the imaging experiments are expected to be ready in early FY2021. We have also pursued the syntheses of novel PAHs with unprecedented aromatic structures, and several compounds are currently under purification in parallel with the optimization of their synthesis. 

3.2 On-Surface Synthesis of Graphene Nanoribbons 

Graphene nanoribbons (GNRs) are nanometer-wide strips of graphene, which show intriguing edge-structure-dependent electronic properties (cf. publication 1 in 4.1.2 below). Through atomically precise control of the edge structures of GNRs using the bottom-up synthesis method, it is possible to modulate the bandgap and also to induce localized spins at specific peripheral sites (cf. publications 3, 8 in 4.1.1). We have continued to explore new molecular precursors for the bottom-up synthesis of unprecedented GNRs on metals surface, in collaboration with the group of Prof. Roman Fasel at Empa. In FY2019, we have designed and synthesized 8,8'-dibromo-5,5'-bibenzo[rst]pentaphene a new monomer precursor in an attempt to synthesize N = 8 armchair GNRs, which are theoretically predicted to have a very small bandgap. Unfortunately, this monomer failed to provided the desired GNR, but led to the formation of two unprecedented GQDs, dibenzohexacenohexacene and dibenzopentaphenoheptaphene, which could be unambiguously visualized by noncontact atomic force microscopy (nc-AFM) (publication 4 in 4.1.1). On the other hand, we had also synthesized monomer precursors bearing o-tolyl groups, and succeeded in the synthesis of novel pentagon-fused GNRs through the on-surface activation and cyclization of benzylic C-H groups (Nano Res. 2021, to be included in the list of FY2021). We have also synthesized other monomer precursors for the on-surface synthesis of unique GNRs with low bandgaps and/or localized electronic states, which are currenlty under investigations. 

4. Publications

4.1 Journals

4.1.1 Original Research Articles
  1. Q. Chen, M. Baumgarten, M. Wagner, Y. Hu, I. C.-Y. Hou, A. Narita,* K. Müllen,* Dicyclopentaannelated Hexa-peri-hexabenzocoronenes with a Singlet Biradical Ground State. Angew. Chem. Int. Ed. 2021, Early View, DOI: 10.1002/anie.202102932.
  2. Z. Qiu, C.-W. Ju, L. Frédéric, Y. Hu, D. Schollmeyer, G. Pieters,* K. Müllen,* A. Narita,* Amplification of Dissymmetry Factors in π-Extended [7]- and [9]Helicenes. J. Am. Chem. Soc. 2021143, 4661–4667.
  3. P. P. Shinde, J. Liu, T. Dienel, O. Gröning, T. Dumslaff, M. Mühlinghaus, A. Narita, K. Müllen, C. A. Pignedoli, R. Fasel, P. Ruffieux, D. Passerone, Graphene nanoribbons with mixed cove-cape-zigzag edge structure. Carbon 2021175, 50–59.
  4. X. Xu, A. Kinikar, M. D. Giovannantonio, P. Ruffieux, K. Müllen,* R. Fasel,* A. Narita,* On-Surface Synthesis of Dibenzohexacenohexacene and Dibenzopentaphenoheptaphene. Bull. Chem. Soc. Jpn. 202194, 997–999. (Invited contribution to BCSJ Diamond collection: Frontiers of Molecular Science)
  5. H. Chang, H. Liu, E. Dmitrieva, Q. Chen, J. Ma, P. He, P. Liu, A. A. Popov, X.-Y. Cao, X.-Y. Wang, Y. Zou, A. Narita, K. Müllen, H. Peng, Y. Hu, Furan-containing double tetraoxa[7]helicene and its radical cation. Chem. Commun202056, 15181–15184.
  6. Y. Zhou, X. Tao, G. Chen, R. Lu, D. Wang, M.-X. Chen, E. Jin, J. Yang, H.-W. Liang, Y. Zhao, X. Feng, A. Narita,* K. Müllen,* Multilayer stabilization for fabricating high-loading single-atom catalysts. Nat. Commun202011, 5892.
  7. Z. Qiu, S. Asako,* Y. Hu, C.-W. Ju, T. Liu, L. Rondin, D. Schollmeyer, J.-S. Lauret, K. Müllen,* A. Narita,* Negatively Curved Nanographene with Heptagonal and [5]Helicene Units. J. Am. Chem. Soc2020142, 14814–14819.
  8. Q. Sun, X. Yao, O. Gröning, K. Eimre, C. A. Pignedoli, K. Müllen, A. Narita,* R. Fasel, P. Ruffieux,* Coupled Spin States in Armchair Graphene Nanoribbons with Asymmetric Zigzag Edge Extensions. Nano Lett202020, 6429–6436.
  9. I. C.-Y. Hou, F. Berger, A. Narita,* K. Müllen,* S. Hecht,* Proton‐Gated Ring‐Closure of a Negative Photochromic Azulene‐Based Diarylethene. Angew. Chem. Int. Ed202059, 18532–18536.
  10. M. Di Giovannantonio,* X. Yao, K. Eimre, J. I. Urgel, P. Ruffieux, C. A. Pignedoli,* K. Müllen,* R. Fasel, A. Narita,* Large-Cavity Coronoids with Different Inner and Outer Edge Structures. J. Am. Chem. Soc2020142, 12046–12050.
  11. I. C.-Y. Hou, Q. Sun, K. Eimre, M. Di Giovannantonio, J. I. Urgel, P. Ruffieux, A. Narita,* R. Fasel,* K. Müllen,* On-Surface Synthesis of Unsaturated Carbon Nanostructures with Regularly Fused Pentagon–Heptagon Pairs. J. Am. Chem. Soc2020142, 10291–10296. (Selected as the Supplementary Cover
4.1.2 Review Article
  1. Z. Chen,* A. Narita,* K. Müllen,* Graphene Nanoribbons: On-Surface Synthesis and Integration into Electronic Devices. Adv. Mater202032, 2001893.
4.1.3 Articles without peer-review
  1. X. Xu, Q. Chen, A. Narita,* Synthesis and Characterization of Dibenzo[hi,st]ovalene as a Highly Fluorescent Polycyclic Aromatic Hydrocarbon and Its π-Extension to Circumpyrene. J. Synth. Org. Chem., Jpn. 202078, 1094–1104 (有機化学合成協会誌).
  2. 成田明光, 0次元〜2次元カーボンナノマテリアルのボトムアップ精密合成, 日本セラミックス協会誌「セラミックス」, 2020, 55, 8.  (A. Narita, Bottom-up Precision Synthesis of 0 ~ 2-Dimensional Carbon Nanomaterials, Ceramics Japan, 2020, 55, 8, 556–559.)

4.2 Books and other one-time publications

Nothing to report

4.3 Oral and Poster Presentations

Invited Talks at Conferences and Symposiums
  1. Narita, A. 新規多環芳香族炭化水素やグラフェンナノリボンの合成と機能開拓, 有機若手ワークショップ (online), Kyoto University, Kyoto, Japan, November 12, 2020.
  2. Narita, A. Bottom-Up Solution Synthesis of Structurally Well-Defined Graphene Nanoribbons—Modulation of the Width and Edge Functionalization, 2020 Virtual MRS Spring/Fall Meeting & Exhibit, November 28, 2020.
  3. Narita, A. グラフェンナノリボンの合成と新規多環芳香属炭化水素への展開, GTR Chemistry Workshop 2020 (online), Nagoya University, Nagoya, Japan, December 7, 2020.
  4. Narita, A. グラフェンナノリボンやグラフェン量子ドットのボトムアップ精密合成, Graphene Oxide Symposium (online), Kumamoto University, Kumamoto, Japan, December 11, 2020 
  5. Narita, A. 低次元ナノカーボン材料の精密合成 (Precision Synthesis of Low-Dimensional Nanocarbon Materials), The 101st Chemical Society of Japan Annual Meeting (online Meeting), March 19, 2021.
  1. Narita, A. Bottom-Up Chemical Synthesis of Atomically Precise Graphene Nanostructures. Virtual DCMIC Seminar Series, Zoom, Department of Chemistry, Materials and Chemical Engineering “Giulio Natta” (CMIC), Polytechnic University of Milan, Italy, November 27, 2020.
  2. Narita, A. Synthesis and Applications of Functional Polycyclic Aromatic Hydrocarbons and Graphene Nanoribbons, Invited Seminar (online), Department of Applied Chemistry, The University of Tokyo, November 30, 2020.

5. Intellectual Property Rights and Other Specific Achievements

Nothing to report

6. Meetings and Events

Nothing to report

7. Other

Nothing to report