Faculty Profiles - YOSHIDA Takefumi

Published Papers - YOSHIDA Takefumi

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Dual-Redox System of Metallo-Supramolecular Polymers for Visible-to-Near-IR Modulable Electrochromism and Durable Device Fabrication

Sanjoy Mondal, Dines Chandra Santra, Yoshikazu Ninomiya, Takefumi Yoshida, Masayoshi Higuchi

ACS Applied Materials & Interfaces ( American Chemical Society (ACS) ) 12 ( 52 ) 58277 - 58286 2020.12 [Refereed]

Dual-redox metallo-supramolecular polymers with a zigzag structure (polyFe-N and polyRu-N) were successfully synthesized by 1:1 complexation of a redox-active Fe(II) or Ru(II) ion and 4,4-bis(2,2:6,2-terpyridinyl)phenyl-triphenylamine (L-TPA) as a redox-active ligand. The polymers had high solubility in methanol, and the polymer solutions showed dark brown (polyFe-N) or orange-red (polyRu-N) coloration. UV-vis spectra of the polymers displayed a strong metal-to-ligand charge transfer (MLCT) absorption in the visible region. Cyclic voltammograms of the polymer films exhibited two pairs of reversible redox waves. The first redox at similar to 0.5 V versus Ag/Ag+ was assigned to the redox in the triphenylamine (TPA) moiety of L-TPA, and the second redox at 0.8 V versus Ag/Ag+ (polyFe-N) or 0.9 V versus Ag/Ag+ (polyRu-N) was given to the redox of Fe(II)/(III) or Ru(II)/(III), respectively. Upon applying a positive potential of more than 0.5 V versus Ag/Ag+ to the polymer films, a new absorption at similar to 820 nm in the near-infrared (NIR) region appeared with wide tailing to the longer wavelength. It is considered that the new absorption in the NIR region is caused by the polaron band of the oxidized ligand in the polymers. When the applied potential was increased to 1.0 V versus Ag/Ag+ (polyFe-N) or 1.1 V versus Ag/Ag+ (polyRu-N), the maximum wavelength of the new absorption in the NIR region shifted to 885-900 nm and the absorbance was further enhanced with disappearance of the MLCT absorption. Eventually, the original colors of the polymers were faint to light green. This visible-to-NIR electrochromism was reversible, and maximum optical contrast (Delta T) reached 52% in the visible region and 80% in the NIR region. A prototype solid-state device with the polymer was fabricated for practical utilization, exhibiting excellent cycle stability of >4000 cycles with maintaining high optical contrast from the visible-to-NIR range.

Correction to: Synchrotron-radiation-based Mössbauer absorption spectroscopy with high resonant energy nuclides (Hyperfine Interactions, (2019), 240, 1, (120), 10.1007/s10751-019-1672-x)

Ryo Masuda, Kohei Kusada, Takefumi Yoshida, Shinji Michimura, Yasuhiro Kobayashi, Shinji Kitao, Hiroyuki Tajima, Takaya Mitsui, Hirokazu Kobayashi, Hiroshi Kitagawa, Makoto Seto

Hyperfine Interactions 241 ( 1 ) 2020.12 [Refereed]

One-Pot Synthesis of Three-Dimensionally Hyperbranched Eu/Fe-Based Heterometallo-Supramolecular Polymers as Thermally Tough Proton-Conducting Nanoparticles

Yemineni S. L. V. Narayana, Utpal Rana, Chanchal Chakraborty, Takefumi Yoshida, Masayoshi Higuchi

ACS Applied Polymer Materials ( American Chemical Society (ACS) ) 2020.08 [Refereed]

Ni(II)-Based Metallosupramolecular Polymer with Carboxylic Acid Groups: A Stable Platform for Smooth Imidazole Loading and the Anhydrous Proton Channel Formation

Yemineni S L V Narayana, Takefumi Yoshida, Manas Kumar Bera, Sanjoy Mondal, Masayoshi Higuchi

ACS Omega ( American Chemical Society (ACS) ) 5 ( 24 ) 14796 - 14804 2020.06 [Refereed]

Dual-Branched Dense Hexagonal Fe(II)-Based Coordination Nanosheets With Red-to-Colorless Electrochromism and the Durable Device Fabrication

Sanjoy Mondal, Yoshikazu Ninomiya, Takefumi Yoshida, Taizo Mori, Manas Kumar Bera, Katsuhiko Ariga, Masayoshi Higuchi

ACS Applied Materials & Interfaces ( American Chemical Society (ACS) ) 12 ( 28 ) 31896 - 31903 2020.06 [Refereed]

Highly dense hexagonal Fe(II)-based coordination nanosheets (CONASHs) were designed by dual-branching, at the metal-coordination moieties and the tritopic ligands, which successfully obtained a liquid/liquid interface by the complexation of Fe(II) ions and the tritopic bidentate ligands. The 1:1 complexation was confirmed by titration. The obtained Fe(II)-based nanosheets were fully characterized by small-angle X-ray scattering (SAXS), atomic force microscopy (AFM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray photoelectron spectroscopy (XPS). A monolayer of the sheets was obtained, employing the Langmuir-Blodgett (LB) method, and the determined thickness was similar to 2.5 nm. The polymer nanosheets exhibited red-to-colorless electrochromism because the electrochemical redox transformation between Fe(II) and Fe (III) ions controlled the appearance/disappearance of the metal (ion)-to-ligand charge-transfer (MLCT) absorption. The poor pi-conjugation in the tritopic ligands contributed to the highly colorless electrochromic state. A solid-state device, with the robust polymer film, exhibited excellent electrochromic (EC) properties, with high optical contrast (Delta T > 65%) and high durability after repeated color changes for >15 000 cycles, upon applying low-operating voltages (+1.5/0 V).

Electrochromic Fe(II)-Based Metallo-Supramolecular Polymers: Color Modulation by Spacer Modification in Bisterpyridine Ligand

Yoshikazu Ninomiya, Takefumi Yoshida, Masayoshi Higuchi

Chemistry Letters ( The Chemical Society of Japan ) 49 ( 9 ) 1003 - 1005 2020.05 [Refereed]

We synthesized Fe(II)-based metallo-supramolecular polymers with bisterpyridines bearing ethynylene, phenylene, and durene as spacer (polyFeL1-3) and investigated the effect of the spacer modification on the electrochromic properties. We revealed the redox potential and MLCT absorption of polymers were greatly influenced by the spacer alteration. PolyFeL1-3 exhibited different colors; blue, bluish purple, and purple, respectively. Blue- and purple-colored electrochromic devices were successfully fabricated using polyFeL1 and polyFeL3. The electrochromic color changes were observed upon applying +3V for bleaching or -3V for coloring.

Transparent Supercapacitor Display with Redox-Active Metallo-Supramolecular Polymer Films

Sanjoy Mondal, Takefumi Yoshida, Subrata Maji, Katsuhiko Ariga, Masayoshi Higuchi

ACS APPLIED MATERIALS & INTERFACES ( AMER CHEMICAL SOC ) 12 ( 14 ) 16342 - 16349 2020.04 [Refereed]

The use of metallo-supramolecular polymer (MSP) as a thin-film-based redox supercapacitor electrode material is reported for the first time. Fe(II)- and Ru(II)-based MSPs (polyFe and polyRu, respectively) were synthesized by complexation of appropriate metal salts with 4',4 ''-(1,4-phenylene)bis-2,2':6',2 ''-terpyridine, and thin films of these polymers were prepared by spray coating onto an indium tin oxide glass substrate. A study of the energy storage performances of the polyFe and polyRu films in a nonaqueous electrolyte system revealed volumetric capacitances of similar to 62.6 +/- 3 F/cm(3) for polyFe and 98.5 +/- 7 F/cm(3) for polyRu at a current density of 2 A/cm(3). To improve the energy storage performance over a wider potential range, asymmetric supercapacitor (ASC) displays were fabricated with suitable combinations of the MSPs as cathodic materials and Prussian blue as the anodic counter material in a sandwich configuration with a transparent polymeric ion gel as the electrolyte. The fabricated ASCs showed a maximum volumetric energy density (similar to 10-18 mW h/cm(3)) that was higher than that of lithium thin-film batteries and a power density (7 W/cm(3)) comparable to that of conventional electrolyte capacitors, with superb cyclic stability for 10 000 cycles. To demonstrate the practical use of the MSP, the illumination of a light-emitting diode bulb was powered by a laboratory-made device. This work should inspire the development of high-performance thin-film flexible supercapacitors based on MSPs as active cathodic materials.

Reversible four-color electrochromism triggered by the electrochemical multi-step redox of Cr-based metallo-supramolecular polymers

Takefumi Yoshida, Yoshikazu Ninomiya, Masayoshi Higuchi （Part： Lead author )

RSC ADVANCES ( ROYAL SOC CHEMISTRY ) 10 ( 18 ) 10904 - 10909 2020.03 [Refereed]

Four color electrochromism (yellow, magenta, blue, and navy) has been achieved in Cr(iii)-based metallo-supramolecular polymers (polyCr), which were synthesized by 1 : 1 complexation of Cr ions and 1,4-di[[2,2 ':6 ',2 ''-terpyridin]-4 '-yl]benzene (L). The polymer structure was determined by X-ray absorption fine structure (XAFS) measurement and X-ray photoelectron spectroscopy (XPS). The molecular weight of polyCr was calculated as 3.2 x 10(7) Da using right angle light scattering (RALS). The EXAFS fitting indicated that the bond distances of Cr-N are 2.020 angstrom and 2.208 angstrom. A film of polyCr shows multi-color electrochromism (EC) or absorption: a sharp peak at 380 nm at 0 V vs. Ag/Ag+ (yellow), a sharp peak at 510 nm and a broad peak at 800 nm at -0.6 V vs. Ag/Ag+ (magenta), a broad peak at 610 nm and between 700-900 nm at -1.2 V vs. Ag/Ag+ (blue), a broad peak between 450-900 nm at -1.8 V vs. Ag/Ag+ (navy). The transmittances change (Delta T), the switching times for coloring and bleaching (T-c, T-b) and the coloration efficiency (eta(c), eta(b)): [Delta T, (T-c, T-b), (eta(c), eta(b))] were [39.2%, (5.56 s, 1.39 s), (169 cm(2) C-1, 230 cm(2) C-1)] at 510 nm between -0.6 and 0.2 V vs. Ag/Ag+, [67.0%, (6.93 s, 2.52 s), (138 cm(2) C-1, 172 cm(2) C-1)] at 610 nm between -1.2 and 0.2 V vs. Ag/Ag+, [86.1%, (6.80 s, 3.03 s), (167 cm(2) C-1, 134 cm(2) C-1)] at 780 nm between -1.8 and 0.2 V vs. Ag/Ag+, respectively, during the cycles. The durability experiment indicates that polyCr shows an EC property for at least 100 cycles.

Proton Conductivity of Metallo-Supramolecular Polymer Boosted by Lithium Ions

Yemineni S. L. V. Narayana, Takefumi Yoshida, Chanchal Chakraborty, Manas Kumar Bera, Masayoshi Higuchi

ACS APPLIED POLYMER MATERIALS ( AMER CHEMICAL SOC ) 2 ( 2 ) 326 - 334 2020.02 [Refereed]

This is a report to reveal the role of alkali metal ions on proton transfer in metallo-supramolecular polymers (MSPs). We successfully synthesized europium(III)-based MSPs with different counter cations (Li+, Na+, and K+) (polyEu-M+, M = Li, Na, and K, respectively) via 1:1 complexation of Eu(III) salt and tetracarboxylic acid-substituted bisterpyridine in the presence of metal hydroxide (MOH, M = Li, Na, and K). We found that the proton conductivity was dramatically changed by the countercation species of the polymer. Among the three polymers, polyEu-Li+ showed the highest proton conductivity (1.54 x 10(-2) S cm(-1)) at 95% relative humidity (RH) and 75 degrees C and also exhibited the lowest activation energy 0.14 eV at 95% RH. PolyEu-Li+ presented high water uptake (14.58), which was measured by the mass change (%) with respective reference mass, compared with polyEu-Na+ (13.08) and polyEu-K+ (11.50) at 95% RH. The results indicate that effective proton channels enabled by water molecules were formed in the presence of Li+.

Precise Synthesis of Alternate Fe(II)/Os(II)-Based Bimetallic Metallo-Supramolecular Polymer

Manas K. Bera, Yoshikazu Ninomiya, Takefumi Yoshida, Masayoshi Higuchi

MACROMOLECULAR RAPID COMMUNICATIONS ( WILEY-V C H VERLAG GMBH ) 41 ( 1 ) 2020.01 [Refereed]

A novel terpyridine-based bimetallic metallo-supramolecular polymer (polyFeOs) containing alternately complexed Fe(II) and Os(II) ions is synthesized. For precise synthesis of the polymer, a new three-step synthetic pathway is developed to obtain a high yield (%) of product in each step. The first step is the synthesis of dibromo terpyridine-Os(II) complex in 87% yield, the second step is the synthesis of bisterpyridine ligand containing Os(II) (OsL1) in 74% yield, and the last step is the synthesis of polyFeOs in 90% yield. The polyFeOs exhibits high thermal stability with two degradation temperatures at around 390 and 690 degrees C, which indicate thermal evaporation of the counter anions (Cl- and BF4-) and degradation of the coordination bonds, respectively. The combination of two different metal ions in polyFeOs results in an enlarged optical window (lambda = 315-675 nm) and two highly stable reversible redox states, which can be of huge interest for potential optical, electro-optical, and electrochemical applications.

Electrochromic Os-based metallo-supramolecular polymers: electronic state tracking by in situ XAFS, IR, and impedance spectroscopies

Takefumi Yoshida, Manas Kumar Bera, Yemineni S. L. V. Narayana, Sanjoy Mondal, Hitoshi Abe, Masayoshi Higuchi

RSC Advances ( Royal Society of Chemistry (RSC) ) 10 ( 41 ) 24691 - 24696 2020 [Refereed]

An Organic‐Inorganic Hybrid Exhibiting Electrical Conduction and Single‐Ion‐Magnetism

Yongbing Shen, Goulven Cosquer, Hiroshi Ito, David Chukwuma Izuogu, Alex J.W. Thom, Toshiaki Ina, Tomoya Uruga, Takefumi Yoshida, Shinya Takaishi, Brian K. Breedlove, Zhao-Yang Li, Masahiro Yamashita

Angew. Chem. Ed. Int. 59 2399 - 2406 2020 [Refereed]

Ionic-Caged Heterometallic Bismuth–Platinum Complex Exhibiting Electrocatalytic CO2 Reduction

Yoshida Takefumi, Ahsan Md. Habib, Haitao Zhang, David Chukwuma Izuogu, Hitoshi Abe, Hiroyoshi Ohtsu, Tadashi Yamaguchi, Brian K. Breedlove, Alexander James William Thom, Masahiro Yamashita （Part： Lead author,　Corresponding author )

Dalton Trans. 2020 [Refereed]

Simultaneous manifestation of metallic conductivity and single-molecule magnetism in a layered molecule-based compound

Yongbing Shen, Hiroshi Ito, Haitao Zhang, Hideki Yamochi, Seiu Katagiri, Shinji K. Yoshina, Akihiro Otsuka, Manabu Ishikawa, Goulven Cosquer, Kaiji Uchida, Carmen Herrmann, Takefumi Yoshida, Brian K. Breedlove, Masahiro Yamashita

Chemical Science ( Royal Society of Chemistry (RSC) ) 11 ( 41 ) 11154 - 11161 2020 [Refereed]

Emergence of electrical conductivity in a flexible coordination polymer by using chemical reduction

Kentaro Fuku, Momoka Miyata, Shinya Takaishi, Takefumi Yoshida, Masahiro Yamashita, Norihisa Hoshino, Tomoyuki Akutagawa, Hiroyoshi Ohtsu, Masaki Kawano, Hiroaki Iguchi

Chemical Communications ( Royal Society of Chemistry (RSC) ) 56 ( 61 ) 8619 - 8622 2020 [Refereed]

Periodicity of Single‐Molecule Magnet Behaviour of Heterotetranuclear Lanthanide Complexes Across the Lanthanide Series: A Compendium

David Chukwuma Izuogu, Yoshida Takefumi, Goulven Cosquer, Jonnie N. Asegbeloyin, Haitao Zhang, Alex J. W. Thom, Masahiro Yamashita

Chem. Eur. J. 2020 [Refereed]

Conductive zigzag Pd(III)–Br chain complex realized by multiple-hydrogen-bond approach

Mohammad Rasel Mian, Unjila Afrin, Hiroaki Iguchi, Shinya Takaishi, Takefumi Yoshida, Tatsuya Miyamoto, Hiroshi Okamoto, Hisaaki Tanaka, Shin-ichi Kuroda, Masahiro Yamashita

CrystEngComm 22 ( 23 ) 3999 - 4004 2020 [Refereed]

© The Royal Society of Chemistry 2020. Coexistence of zigzag structure and the uncommon Pd(iii) oxidation state in quasi-1D halogen-bridged metal complexes was realized in a conductive Br-bridged Pd chain complex, [Pd(dabdOH)2Br]SO4·3H2O (2), for the first time. Intra- and interchain hydrogen-bond networks among the (2S,3S)-2,3-diaminobutane-1,4-diol (dabdOH) ligand and SO42−and H2O molecules support this unusual structure and electronic state. The electrical conductivity of2reached 0.05 S cm−1at room temperature.

Electrochromic devices using Fe(II)-based metallo-supramolecular polymer: Introduction of ionic liquid as electrolyte to enhance the thermal stability

Sanjoy Mondal, Takefumi Yoshida, Masayoshi Higuchi

JOURNAL OF THE SOCIETY FOR INFORMATION DISPLAY ( WILEY ) 27 ( 11 ) 661 - 666 2019.11 [Refereed] [Invited]

We fabricated electrochromic (EC) devices with Fe(II)-based metallo-supramolecular polymer (polyFe), 1-butyl-1-methyl-pyrrolidinium bis(trifluoromethanesulfonyl)imide (BMPyr(NTf)(2)) ionic liquid (IL), and Prussian blue (PB) as electrochromic layer, electrolyte layer, and counter layer, respectively. Thermal stability and ionic conductivity of BMPyr(NTf)(2) IL was measured by thermogravimetric analysis (TGA) and impedance analysis to be 380 degrees C and approximately 7.8 x 10(-4) S/cm, respectively. The fabricated device showed reversible electrochromism between bluish-violet and colorless by applying +3.0/-1.5 V alternately. The 65% of the original EC contrast remained in the device after the repeated changes for 100 cycles at 100 degrees C.

Thermally stable electrochromic devices using Fe(II)-based metallo-supramolecular polymer

Sanjoy Mondal, Takefumi Yoshida, Utpal Rana, Manas Kumar Bera, Masayoshi Higuchi

SOLAR ENERGY MATERIALS AND SOLAR CELLS ( ELSEVIER ) 200 110000 2019.09 [Refereed] [Invited]

A solid-state electrochromic (EC) device with high thermal durability was successfully fabricated by the combination of Fe(II)-based metallo-supramolecular polymer (polyFe) as a cathodically coloring EC layer, a poly (methyl methacrylate)-based solid-state electrolyte layer, and Prussian blue (PB) as an anodically coloring EC layer between two indium tin oxide (ITO)-coated glass conducting substrates. Spray coating technique was used to make polyFe film on ITO-glass. Counter materials were investigated to improve the long-term durability and performance of solid state devices. The polyFe layer thickness was optimized at 240 +/- 50 nm, resulting in better electrochromic performance of the fabricated device with transmittance change of similar to 54% and 95% cyclic stability after 1000 cycles with a short response time by applying voltages of +2.7 V and -1.3 V reversibly. Importantly, the thermal stability of the fabricated solid device was also explored, and we achieved maximum temperature stability at 100 degrees C with 50% retention of device properties in this study.

Construction of Coordination Nanosheets Based on Tris(2,2 '-bipyridine)-Iron-(Fe2+) Complexes as Potential Electrochromic Materials

Manas Kumar Bera, Taizo Mori, Takefumi Yoshida, Katsuhiko Ariga, Masayoshi Higuchi

ACS APPLIED MATERIALS & INTERFACES ( AMER CHEMICAL SOC ) 11 ( 12 ) 11893 - 11903 2019.03 [Refereed]

The coordination nanosheets (CONASHs) are emerging as a new class of functional two-dimensional materials, which are one of the most active research areas of chemistry and physics in this decade. Despite the success of various structural and functional CONASHs, the development of a new molecular structure to discover alluring functional CONASHs remains challenging. Herein, we report successful preparation of two novel CONASHs (NBP1 and NBP2) through coordination between one of the unexplored molecular frameworks of bis(2,2'-bipyridine)-based ligands (BP1 and BP2) and Fe2+ ions. Using a liquid-liquid interface as a platform, large-scale thin films of multilayer CONASHs have been prepared without any support, which can be deposited onto any desired substrate. Detailed characterization of the CONASHs using various microscopic and spectroscopic techniques reveals homogeneous and flat morphology of nanometer thickness with the quantitative formation of tris(2,2'-bipyridine)-Fe2+ complex motifs in the nanosheet frameworks. The color of the films has been tuned from blue to magenta by the suitable molecular design of the ligands. Owing to the insolubility of the CONASH films in any solvent and the presence of redox-active Fe2+, we explore the functionality of these nanostructured thin films deposited on indium tin oxide as electrochromic materials. The CONASHs exhibit color-to-colorless and color-to-color electrochromic transitions with attractive response times, switching stabilities, and coloration efficiencies. Finally, we demonstrate solid-state electrochromic devices of the CONASHs operated at a potential range of +2.5 to -2.5 V, which are electrochemically stable for several switching cycles, suggesting that these CONASHs are potential electrochromic materials for next-generation display applications.

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