Kyushu University Academic Staff Educational and Research Activities Database
List of Papers
Naoki Tanaka Last modified date:2023.10.12

Assistant Professor / Department of Applied Chemistry / Faculty of Engineering

1. Yuki Motoishi, Chearin Kim, Naoki Tanaka, Tsuyohiko Fujigaya, Molecular Assembly of Alkylated Fused Expanded Pyridinium for a Highly Conductive Anion-Exchange Membrane, Chemistry of Materials,, 2023.09.
2. Naoki Tanaka, Itsuki Yamaguchi, Ryohei Yamaguchi, Tsuyohiko Fujigaya, Study of electron doping mechanism in single-walled carbon nanotubes using dimethylbenzimidazole, Faraday Discussion,, 2023.07.
3. Yuki Motoishi, Naoki Tanaka, Tsuyohiko Fujigaya, Postmodification of highly delocalized cations in an azide-based polymer via copper-catalyzed cycloaddition for anion exchange membranes, Polymer Journal,, 55, 171-180, 2022.11.
4. Tomohiro Shiraki, Rioe Saito, Hayato Saeki, Naoki Tanaka, Koji Harano, Tsuyohiko Fujigaya, Defect Photoluminescence from Alkylated Boron Nitride Nanotubes, Chemistry Letters, 10.1246/cl.220467, 52, 1, 44-47, 2022.11.
5. Yin Kan Phua, Weerathunga don Terrence Dhammika, Wu Dan, Kim Chaerin, Samindi Jayawickrama, Naoki Tanaka, Tsuyohiko Fujigaya, Effect of Surface Roughness of Carbon Nanotube-based Catalyst Layer for Polymer Electrolyte Membrane Fuel Cell Performance, Sustainable Energy & Fuels, 6, 11422-11425, 2022.09.
6. Yin Kan Phua, Don Terrence Dhammika Weerathunga, Dan Wu, Chaerin Kim, Samindi Madhubha Jayawickrama, Naoki Tanaka, Tsuyohiko Fujigaya, Effect of carbon nanotube-based catalyst layer surface roughness on polymer electrolyte membrane fuel cell performance, Sustainable Energy & Fuels, 10.1039/d2se00857b, 6, 4636-4644, 2022.09, One of the advantages of CNT-based fuel cell catalysts is the formation of free-standing sheets based on filtration. The sheets have a smoother side depending on the filtration direction, which result in the higher performance in the cell..
7. Dan Wu, Samindi Jayawickrama, Naoki Tanaka, Tsuyohiko Fujigaya, Effect of Polymer-coating on Acetylene Black for Durability of Polymer Electrolyte Membrane Fuel Cell, Journal Power Sources, 549, 2022.05.
8. Ahmed E. Mansour, Ana M. Valencia, Dominique Lungwitz, Berthold Wegner, Naoki Tanaka, Yoshiaki Shoji, Takanori Fukushima, Andreas Opitz, Caterina Cocchi, Norbert Koch , Understanding the evolution of the Raman spectra of molecularly p-doped poly(3-hexylthiophene-2,5-diyl): signatures of polarons and bipolarons, Physical Chemistry Chemical Physics, DOI, 24, 3109-3118, 2022.01.
9. Yoshiaki Shoji, Naoki Tanaka, Yasuhiro Ikabata, Hayato Sakai, Taku Hasobe, Norbert Koch, Hiromi Nakai, Takanori Fukushima, Tetraaryldiborane(4) Can Emit Dual Fluorescence Responding to the Structural Change around the B–B Bond, Angewandte Chemie International Edition, 2021.10, ジメシチルボリニウムイオンの還元的カップリングにより、これまで単離が困難であったテトラメシチルジボラン(4)(Mes4B2)の合成に成功した。メシチル基による立体保護により、Mes4B2は化学的に極めて安定であり、水中でも安定に存在できる。Mes4B2は、溶液中でも固体状態でも460nmと620nmの二重蛍光を有することが明らかになった。理論計算の結果、励起S1状態のMes4B2はねじれた形状または平面形状をとり、それぞれ短波長蛍光または長波長蛍光の原因であることがわかった。二重蛍光の強度比は媒体の粘度に敏感であることから、この特徴を利用してMes4B2は粘度センサーとしての可能性が示唆された。.
10. Hoon Han, Hiroto Miura, Yuki Motoishi, Naoki Tanaka, Tsuyohiko Fujigaya, Development of Proton Exchange Membrane Based on Trifluoromethanesulfonylimide-grafted Polybenzimidazole, Polymer Journal, 2021.08.
11. Yuki Motoishi, Naoki Tanaka, Tsuyohiko Fujigaya, Synthesis and Anion Conductivity of Anion-Exchange Membrane with Fused Expanded Pyridinium Structure as Cationic Moiety, Chemistry Letters, 2021.05.
12. Ryohei Yamaguchi, Taiki Ishii, Masamichi Matsumoto, Borah Angana, Naoki Tanaka, Kaito Oda, Motohiro Tomita, Takanobu Watanabe, Tsuyohiko Fujigaya, Thermal Deposition Method for p–n Patterning of Carbon Nanotube Sheets for Planar-type Thermoelectric Generator, Journal of Materials Chemistry A, 2021.05.
13. Naoki Tanaka, Aoi Hamasuna, Takuto Uchida, Ryohei Yamaguchi, Taiki Ishii, Aleksandar Staylkov, Tsuyohiko Fujigaya, Electron doping of single-walled carbon nanotubes using pyridine-boryl radicals, Chemical Communications, 10.1039/D1CC01354H, 57, 49, 6019-6022, 2021.05, Pyridine-boryl (py-boryl) radicals serve as efficient electron-doping reagents for single-walled carbon nanotubes (SWCNTs). The doping mechanism comprises electron transfer from the py-boryl radical to the SWCNT. The formation of a stable py-boryl cation is essential for efficient doping; the captodative effect of the py-boryl cation is important to this process..
14. Beatrice Adelizzi, Pongphak Chidchob, Naoki Tanaka, Brigitte A. G. Lamers, Stefan C. J. Meskers, Soichiro Ogi, Anja R. A. Palmans, Shigehiro Yamaguchi, E. W. Meijer, Long-Lived Charge-Transfer State from B–N Frustrated Lewis Pairs Enchained in Supramolecular Copolymers, Journal of the American Chemical Society, 2020.09, 近年開発が盛んに行われている機能性超分子ポリマーの作製に向けて、今回新たにフラストレイテドルイスペアーを組み込んだ超分子共重合体を作製し、その特異な光学特性を明らかにした。また共重合体の微細構造を分光測定、理論化学計算から考察し、集積体形成のメカニズムを評価した。.
15. Berthold Wegner, Dominique Lungwitz, Ahmed E. Mansour, Claudia E. Tait, Naoki Tanaka, Tianshu Zhai, Steffen Duhm, Michael Forster, Jan Behrends, Yoshiaki Shoji, Andreas Opitz, Ullrich Scherf, Emil J. W. List‐Kratochvil, Takanori Fukushima, Norbert Koch, An Organic Borate Salt with Superior p‐Doping Capability for Organic Semiconductors, Advanced Science, 10.1002/advs.202001322, 7, 2001322, 2020.07.
16. Formation of environmentally stable hole-doped graphene films with instantaneous and high-density carrier doping via a boron-based oxidant
Large-area graphene films have substantial potential for use as next-generation electrodes because of their good chemical stability, high flexibility, excellent carrier mobility, and lightweight structure. However, various issues remain unsolved. In particular, high-density carrier doping within a short time by a simple method, and air stability of doped graphene films, are highly desirable. Here, we demonstrate a solution-based high-density (>10(14) cm(-2) ) hole doping approach that promises to push the performance limit of graphene films. The reaction of graphene films with a tetrakis(pentafluorophenyl)borate salt, containing a two-coordinate boron cation, achieves doping within an extremely short time (4 s), and the doped graphene films are air stable for at least 31 days. X-ray photoelectron spectroscopy reveals that the graphene films are covered by the chemically stable anions, resulting in an improved stability in air. Moreover, the doping reduces the transmittance by only 0.44 +/- 0.23%. The simplicity of the doping process offers a viable route to the large-scale production of functional graphene electrodes..
17. Chemical hole doping into large-area transition metal dichalcogenide monolayers using boron-based oxidant
Hole carrier doping into single-crystalline transition metal dichalcogenide (TMDC) films can be achieved with various chemical reagents. However, large-area polycrystalline TMDC monolayers produced by a chemical vapor deposition (CVD) growth method have yet to be chemically doped. Here, we report that a salt of a two-coordinate boron cation, Mes(2)B(+) (Mes: 2,4,6-trimethylphenyl group), with a chemically stable tetrakis( pentafluorophenyl) borate anion, [(C6F5)(4)B](-), can serve as an efficient hole-doping reagent for large-area CVD-grown tungsten diselenide (WSe2) films. Upon doping, the sheet resistance of large-area polycrystalline WSe2 monolayers decreased from 90 G Omega/sq to 3.2 k Omega/sq. (C) 2018 The Japan Society of Applied Physics.
18. Naoki Tanaka, Yoshiaki Shoji, Daisuke Hashizume, Manabu Sugimoto, Takanori Fukushima, Formation of an Isolable Divinylborinium Ion through Twofold 1,2-Carboboration between a Diarylborinium Ion and Diphenylacetylene, Angewandte Chemie - International Edition, 10.1002/anie.201701730, 56, 19, 5312-5316, 2017.03, © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Borinium ions, that is, two-coordinate boron cations, are the most electron-deficient isolable boron compounds. As borinium ions have only four formal valence electrons on boron, they should show a strong tendency to accept electron pairs on the boron atom to fill its valence shell. Thus chemical reactions of borinium ions are expected to give products in which the coordination number of boron is increased from two to three or four. However, contrary to this expectation, we found that the dimesitylborinium ion (Mes2B+) undergoes twofold 1,2-carboboration reactions with two equivalents of diphenylacetylene to yield an unprecedented borinium ion (1+) with two substituted vinyl groups on the boron center. NMR spectroscopy and X-ray diffraction analysis of 1+, together with electronic-structure calculations, revealed that the positive charge is delocalized over the entire π-conjugated system. The fact that the chemical transformation of a borinium ion gives rise to a different borinium ion without a change in the coordination number is remarkable and should provide new insight into the chemistry of the Group 13 elements..
19. Highly air- and moisture-stable hole-doped carbon nanotube films achieved using boron-based oxidant
Hole doping into carbon nanotubes can be achieved. However, the doped nanotubes usually suffer from the lack of air and moisture stability, thus, they eventually lose their improved electrical properties. Here, we report that a salt of the two-coordinate boron cation Mes2B+(Mes: 2,4,6-trimethylphenyl group) can serve as an efficient hole-doping reagent to produce nanotubes with markedly high stability in the presence of air and moisture. Upon doping, the resistances of the nanotubes decreased, and these states were maintained for one month in air. The hole-doped nanotube films showed a minimal increase in resistance even upon humidification with a relative humidity of 90%..
20. A two-coordinate boron cation featuring C-B + -C bonding
Two-coordinate boron cations (R 2 B +), referred to as borinium ions, are chemical species in which the boron bears only four valence electrons, and that are isoelectronic with hypothetical carbon dications (R 2 C 2+). Although lone-pair-donating substituents such as amino groups have enabled the isolation of several borinium ions, diarylated and dialkylated borinium derivatives remain entirely unexplored. Here, we present the synthesis, structure and reactivity of the dimesitylborinium ion, which displays unexpectedly high thermal stability. X-ray crystallography and 11 B NMR spectroscopy, supported by density functional theory calculations, reveal that the borinium ion adopts a linear two-coordinate structure in both the solid state and in solution. The boron centre is stabilized by p € bonding from the mesityl groups and is free from coordination by the counterion or solvent molecules. This diarylborinium ion possesses exceptional Lewis acidity, accepting a pair of electrons from CO 2 to cause an unusual deoxygenation reaction. © 2014 Macmillan Publishers Limited..