研究者詳細 - 吉田　健文

論文 - 吉田　健文

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Macro- and atomic-scale observations of a one-dimensional heterojunction in a nickel and palladium nanowire complex

Masanori Wakizaka, Shohei Kumagai, Hashen Wu, Takuya Sonobe, Hiroaki Iguchi, Takefumi Yoshida, Masahiro Yamashita, Shinya Takaishi

Nature Communications ( Springer Science and Business Media LLC ) 13 ( 1 ) 2022年12月 [査読有り]

<title>Abstract</title>The creation of low-dimensional heterostructures for intelligent devices is a challenging research topic; however, macro- and atomic-scale connections in one-dimensional (1D) electronic systems have not been achieved yet. Herein, we synthesize a heterostructure comprising a 1D Mott insulator [Ni(chxn)<sub>2</sub>Br]Br<sub>2</sub> (<bold>1</bold>; chxn = 1<italic>R</italic>-2<italic>R</italic>-diaminocyclohexane) and a 1D Peierls or charge-density-wave insulator [Pd(chxn)<sub>2</sub>Br]Br<sub>2</sub> (<bold>2</bold>) using stepwise electrochemical growth. It can be considered as the first example of electrochemical liquid-phase epitaxy applied to molecular-based heterostructures with a macroscopic scale. Moreover, atomic-resolution scanning tunneling microscopy images reveal a modulation of the electronic state in the heterojunction region with a length of five metal atoms (~ 2.5 nm), that is a direct evidence for the atomic-scale connection of <bold>1</bold> and <bold>2</bold>. This is the first time that the heterojunction in the 1D chains has been shown and examined experimentally at macro- and atomic-scale. This study thus serves as proof of concept for heterojunctions in 1D electronic systems.

161Dy synchrotron-radiation-based Mössbauer absorption spectroscopy

Ryo Masuda, Shinji Kitao, Hiroyuki Tajima, Hiroki Taniguchi, Takaya Mitsui, Kosuke Fujiwara, Yoshitaka Yoda, Nobumoto Nagasawa, Daisuke Ishikawa, Alfred. Q. R. Baron, Takefumi Yoshida, Tetsu Sato, Keiichi Katoh, Hisao Kobayashi, Makoto Seto

Hyperfine Interactions ( Springer Science and Business Media LLC ) 243 ( 1 ) 2022年12月 [査読有り]

We demonstrate a measurement system for synchrotron-radiation-based Mössbauer absorption spectra with 161Dy using the 25.7 keV nuclear first excited state. Mössbauer spectra of DyF3, Dy metal and DyPc2 (Pc = phthalocyaninato) were obtained and the parameters for the hyperfine structure of 161Dy nuclei in them were evaluated to demonstrate the feasibility of this method. Isomer shifts showed that Dy atoms in all of them are in trivalent state although those in Dy metal was in the region of trivalent metal region. The magnetic hyperfine field of Dy metal of 569 ± 1 T agreed with the literature of the Mössbauer experiments. That of DyPc2 of 489 ± 1 T was reasonable because the ground state of DyPc2 were in the state of Jz = ±13/2. Considering the highly penetrative nature of the 25.7 keV incident radiation, it will be straightforward to apply this method for the study of materials under various conditions such as high pressure, high magnetic fields, and reactive atmospheres.

Porous Mn2+ Magnet with a Pt–Cl Framework: Correlation between Water Vapor Adsorption/Desorption and Slow Magnetic Relaxation

Hirotaka Nakajima, Kaiji Uchida, Takefumi Yoshida, Yoji Horii, Tetsu Sato, Zhang Luming, Satoshi Yamashita, Yasuhiro Nakazawa, Verdad C. Agulto, Makoto Nakajima, Brian K. Breedlove, Masahiro Yamashita, Hiroaki Iguchi, Shinya Takaishi (担当区分：責任著者 )

ChemPhysChem ( Wiley ) e202200618 2022年10月 [査読有り]

We report the water adsorption/desorption behavior and dynamic magnetic properties of the Pt-Cl chain complex [{[Pt(en)2 ][PtCl2 (en)2 ]}3 ][{(MnCl5 )Cl3 }2 ] ⋅ 12H2 O (1). Upon heating 1 in a vacuum, we obtained the dehydrated form [{[Pt(en)2 ][PtCl2 (en)2 ]}3 ][{(MnCl5 )Cl3 }2 ] (1DH). The framework structures of 1 and 1DH are identical, and both complexes underwent slow magnetic relaxation. However, the magnetic relaxation times for 1DH were shorter than those for 1, meaning that the dynamic magnetic properties were controlled upon water vapor adsorption/desorption. From detailed analyses of the dynamic magnetic behavior, a phonon-bottleneck effect contributes to the magnetic relaxation processes. We discuss the mechanism for the changes in the magnetic relaxation processes upon dehydration in terms of the heat capacity and thermal conductivity.

Hydrogen bonding propagated phase separation in quasi-epitaxial single crystals: a Pd-Br molecular insulator

Takefumi Yoshida, Shinya Takaishi, Laurent Guérin, Tatsuhiro Kojima, Hiroyoshi Ohtsu, Masaki Kawano, Tatsuya Miyamoto, Hiroshi Okamoto, Kenichi Kato, Masaki Takata, Yuka Hosomi, Shoji Yoshida, Hidemi Shigekawa, Hisaaki Tanaka, Shin-ichi Kuroda, Hiroaki Iguchi, Brian K. Breedlove, Zhao-Yang Li, Masahiro Yamashita (担当区分：筆頭著者,　責任著者 )

Inorganic Chemistry ( American Chemical Society (ACS) ) 61 ( 35 ) 14067 - 14074 2022年09月

Ni(III) Mott–Hubbard-like State Containing High-Spin Ni(II) in a Semiconductive Bromide-Bridged Ni-Chain Compound

Masanori Wakizaka, Mohammad Rasel Mian, Takefumi Yoshida, Tetsu Sato, Hisaaki Tanaka, Tatsuya Miyamoto, Hiroshi Okamoto, Shinya Takaishi, Hiroaki Iguchi, Masahiro Yamashita

Inorganic Chemistry ( American Chemical Society (ACS) ) 61 ( 25 ) 9504 - 9513 2022年06月 [査読有り]

Halogen-bridged linear chain metal complexes (MX-Chains) are fascinating compounds that have a quasi-one-dimensional (1D) electronic system. In this study, we synthesized the first Ni-based MX-Chain compound having hydroxy groups, i.e., [Ni(dabdOH)2Br]Br2·[Ni(dabdOHx)2Br]0.5·(2-PrOH)0.25·(MeOH)0.25(1·solvent, x = ∼0.6, dabdOH = (2S,3S)-2,3-diaminobutane-1,4-diol). Single-crystal X-ray diffraction revealed that the MX-Chains in 1·solvent formed sheets and single-chain structures in the superlattice. It suggested an MH-like state, whereas the polarized reflection and Raman spectra suggested a CDW-like state. Magnetic and electron spin resonance measurements revealed that both high-spin Ni(II) (∼15%) and low-spin Ni(III) (∼85%) sites are present in the chain structures, i.e., the metal sites show mixed valency. Therefore, we concluded that 1·solvent adopts an intermediate state between the MH and CDW states. Moreover, a single crystal of 1·solvent exhibited semiconductive characteristics along the chain direction. This finding represents a new structural and electronic state of 1D electronic systems as well as MX-Chains.

Hidden Heterometallic Interaction Emerging from Resonant Inelastic X-ray Scattering in Luminescent Tb–Pt Molecules

Takefumi Yoshida, Ahmed Shabana, David Chukwuma Izuogu, Kentaro Fuku, Tetsu Sato, Haitao Zhang, Yukina Yamamoto, Jun Kamata, Hitomi Ohmagari, Miki Hasegawa, Goulven Cosquer, Shinya Takaishi, Takuma Kaneko, Tomoya Uruga, Yasuhiro Iwasawa, Masahiro Yamashita (担当区分：筆頭著者,　責任著者 )

J. Phys. Chem. C ( American Chemical Society ) 2022年04月 [査読有り]

A Novel π-d Conjugated Cobalt Tetraaza[14]annulene based Atomically Dispersed Electrocatalyst for Efficient CO Reduction

Zhifu Liang, Ting Zhang, Pengfei Cao, Takefumi Yoshida, Weiqiang Tang, Xiang Wang, Yong Zuo, Pengyi Tang, Marc Heggen, Rafal E. Dunin-Borkowski, Joan Ramon Morante, Andreu Cabot, Masahiro Yamashita, Jordi Arbiol

Chemical Engineering Journal ( Elsevier BV ) 136129 - 136129 2022年03月 [査読有り]

Elucidating 2D Charge‐Density‐Wave Atomic Structure in an MX–Chain by the 3D‐ΔPair Distribution Function Method**

Laurent Guérin, Takefumi Yoshida, Edoardo Zatterin, Arkadiy Simonov, Dmitry Chernyshov, Hiroaki Iguchi, Bertrand Toudic, Shinya Takaishi, Masahiro Yamashita (担当区分：責任著者 )

ChemPhysChem ( Wiley ) 23 ( 6 ) 2022年02月 [査読有り]

Insight into the Gd–Pt Bond: Slow Magnetic Relaxation of a Heterometallic Gd–Pt Complex

Takefumi Yoshida, Ahmed Shabana, Haitao Zhang, David Chukwuma Izuogu, Tetsu Sato, Kentaro Fuku, Hitoshi Abe, Yoji Horii, Goulven Cosquer, Norihisa Hoshino, Tomoyuki Akutagawa, Alex J. W. Thom, Shinya Takaishi, Masahiro Yamashita (担当区分：筆頭著者,　責任著者 )

Bulletin of the Chemical Society of Japan ( The Chemical Society of Japan ) 95 ( 3 ) 513 - 521 2022年02月 [査読有り]

Lanthanide (Ln) compounds are common research targets in the field of magnetism and optics. Their properties arise from the electron localized in the f-orbital. Moreover, the effect of the covalency between lanthanide and ligands on magnetism attracted significant attention. We provided insight into the Gd–Pt bond (of the heterometallic Ln-Pt complexes: {[Pt(PhSAc)4]Ln[(PhSAc)4Pt]} NEt4·2DMF (Ln = Y(0), La(1), Gd(2); PhSAc = thiobenzoate, NEt4 = tetraethylammonium)); single-crystal polarized X-ray absorption near edge structure (XANES) reveal the electronic states around metal ion, where spectra of Gd-LIII edges show the Gd–Pt direction has the highest covalency (less ionic) around Gd ion in 2. In addition, calculating natural bonding (NBO) analysis, natural population analysis (NPA), LOL, and atoms in molecules (AIM), ab initio calculations reveal the role of metallic and organic ligands in the electronic and magnetic properties of Ln complexes. The slow magnetization relaxation of the Gd complex, which has not been reported previously in the Pt–Gd–Pt system, was observed up to 45K, the highest temperature reported to date among isolated Gd-complexes.

Electro-Oxidation Reaction of Methanol over La2–xSrxNiO4+δ Ruddlesden–Popper Oxides

Preetha Chandrasekharan Meenu, Pralok K. Samanta, Takefumi Yoshida, Niall J. English, Santanu Prasad Datta, Satyapaul A. Singh, Srikanta Dinda, Chanchal Chakraborty, Sounak Roy

ACS Applied Energy Materials ( American Chemical Society (ACS) ) 5 ( 1 ) 503 - 515 2022年01月 [査読有り]

Solid polymorphism and dynamic magnetic properties of dodecylated vanadyl-porphyrinato complex: Spin-lattice relaxations modulated by phase stabilisation

Yoji Horii, Momo Makino, Taro Yamamoto, Shoichi Tatsumi, Hal Suzuki, Mariko Noguchi, Takefumi Yoshida, Takashi Kajiwara, Zhaoyang Li, Masahiro Yamashita

Inorganic Chemistry Frontiers ( Royal Society of Chemistry (RSC) ) 2022年 [査読有り]

A Novel Π-D Conjugated Cobalt Tetraaza[14]Annulene Organic Framework for Efficient Electrocatalytic Co2 Reduction

Zhifu Liang, Ting Zhang, Pengfei Cao, Takefumi Yoshida, Weiqiang Tang, Xiang Wang, Pengyi Tang, Marc Heggen, Rafal E. Dunin-Borkowski, Joan Ramon Morante, andreu cabot, Masahiro Yamashita, Jordi Arbiol

SSRN Electronic Journal ( Elsevier BV ) 2022年

擬一次元ハロゲン架橋金属錯体における相転移及び相分離現象の解明

吉田健文 (担当区分：筆頭著者,　最終著者,　責任著者 )

熱測定 49 ( 4 ) 146 - 152 2022年 [査読有り] [招待有り]

Melamine-Induced Synthesis of a Structurally Perfect Kagomé Antiferromagnet

Yongbing Shen, Kunihisa Sugimoto, Satoshi Yamashita, Takefumi Yoshida, Yasuhiro Nakazawa, Brian. K. Breedlove, Haitao Zhang, Masahiro Yamashita

Chemical Communications ( Royal Society of Chemistry (RSC) ) 58 ( 23 ) 3763 - 3766 2022年 [査読有り]

フロギストン

熱測定 49 181 - 184 2022年

Ru(II)-Based Metallo-Supramolecular Polymer with Tetrakis(N-methylbenzimidazolyl)bipyridine for a Durable, Nonvolatile, and Electrochromic Device Driven at 0.6 V

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

ACS Applied Materials & Interfaces ( American Chemical Society (ACS) ) 13 ( 26 ) 31153 - 31162 2021年06月 [査読有り]

Low-voltage operation, high durability, and long memory time are demanded for electrochromic (EC) display device applications. Metallo-supramolecular polymers (MSPs), composed of a metal ion and ditopic ligand, are one of the recently developed EC materials, and the ligand modification is expected to tune the redox potential of MSP. In order to lower the redox potential of MSP, tetrakis(N-methylbenzimidazolyl)bipyridine (L-Bip) was designed as an electronically rich ligand. Ru-based MSP (polyRu-LBip) was successfully synthesized by 1:1 complexation of RuCl2(DMSO)(4) with LBip. The molecular weight (M-w) was high (8.8 x 10(6) Da) enough to provide a simple H-1 NMR spectrum, of which the proton peaks could be assigned by the comparison with the spectrum of the corresponding mono-Ru complex. The redox potential (E-1/2) between Ru(II/III) was 0.51 V versus Ag/Ag+, which was much lower than the redox potential of previously reported Ru-based MSP with bis(terpyridyl)benzene (0.95 V vs Ag/Ag+). The polymer film exhibited reversible, distinct color changes between violet and light green-yellow upon applying very low potentials of 0 and 0.6 V vs Ag/Ag+, respectively. The appearance and disappearance of the metal-to-ligand charge transfer absorption by the electrochemical redox between Ru(II/III) were confirmed using in situ spectro-electrochemical measurement. A solid-state EC device with polyRu-L-Bip was revealed to have large optical contrast (Delta T 54%), fast response time (1.37 s for bleaching and 0.67 s for coloration), remarkable coloration efficiency (571 cm(2)/C), and high durability for the repeated color changes more than 20,000 cycles. The device also showed a long optical memory time of up to 19 h to maintain 40% to the initial contrast under the open circuit conditions. It is considered that the stabilization of the Ru(III) state by L-Bip suppressed the self-coloring to Ru(II) inside the device.

One-Step Synthesis of a Three-Dimensionally Hyperbranched Fe(II)-Based Metallo-Supramolecular Polymer Using an Asymmetrical Ditopic Ligand for Durable Electrochromic Films with Wide Absorption, Large Optical Contrast, and High Coloration Efficiency

Yemineni S. L. V. Narayana, Sanjoy Mondal, Utpal Rana, Yoshikazu Ninomiya, Dines Chandra Santra, Takefumi Yoshida, Masayoshi Higuchi

ACS Applied Electronic Materials ( American Chemical Society (ACS) ) 3 ( 5 ) 2044 - 2055 2021年04月 [査読有り]

For the development of durable electrochromic (EC) materials with wide absorption, large optical contrast, and high coloration efficiency, a three-dimensionally hyperbranched Fe(II)-based metallo-supramolecular polymer (polyFe3-D) was one-step synthesized by the complexation of an Fe(II) salt and an asymmetrical ditopic ligand (L) containing terpyridine (tpy) and phenanthroline (phen) moieties, according to the formation of a 1:2 complex of Fe(II) and tpys (Fe-tpys) and a 1:3 complex of Fe(II) and phens (Fe-phens). The formation of Fe-tpys and Fe-phens was confirmed by the appearance of two metal-to-ligand charge transfer (MLCT) absorptions in the visible area during the titration experiment. The molecular weight (M-w) of polyFe-3D was determined to 3.96 x 10(5) Da by a size-exclusion chromatography-viscometry measurement. PolyFe-3D with the two different Fe(II) complexes (Fe-typs and Fe-phens) exhibited a pair of redox waves for Fe(II/III) (E-1/2 = 0.74 V vs Ag/Ag+) reversibly in the cyclic voltammograms. The linear relationship between the peak current and the root of the scan rate during redox suggested a diffusion-controlled redox reaction. The spin-coated polymer film showed reversible EC changes between magenta and pale green, caused by the redox of Fe(II/III). A wide visible region from 430 to 640 nm was covered with the two MLCT absorptions of the Fe-tpys and Fe-phens moieties. The broad MLCT absorption disappeared upon applying 1.2 V vs Ag/Ag+ and reappeared at 0 V vs Ag/Ag+. The EC changes were revealed to have both a large transmittance change (Delta T) with 70% at 573 nm and a very high coloration efficiency (eta) with 689 cm(2)/C. The coloration efficiency exceeded those of the reported linear (one-dimensional), two-dimensional nanosheeted, and three-dimensional hyperbranched Fe(II)-based metallo-supramolecular polymers. A polyFe-3D film showed high durability for the EC changes of more than 1000 cycles. A solid-state simple device fabricated using polyFe-3D exhibited reversible EC changes of more than 1000 cycles without degradation.

Emergence of Metallic Conduction and Cobalt(II)-Based Single-Molecule Magnetism in the Same Temperature Range

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

Journal of the American Chemical Society ( American Chemical Society (ACS) ) 143 ( 13 ) 4891 - 4895 2021年04月 [査読有り]

Single-molecule magnets exhibit magnetic bistabililties at the molecular level, making them promising for molecule-based spintronics due to high magnetic densities. The incorporation of SMM behavior and electrical conductivity in one compound is rare because these two physical properties often do not operate in the same temperature range, which further hinders their use in practical applications. Here we present an organic-inorganic molecular hybrid, β″-(BEDO-TTF)3[Co(pdms)2]·(MeCN)(H2O)2 (BO3) (BEDO-TTF = bis(ethylenedioxy)tetrathiafulvalene and H2pdms = 1,2-bis(methanesulfonamido)benzene), which manifests both metallic conduction (electrical conductivity up to 1000 S cm-1 at 12 K under 2.0 gigapascal pressure) and SMM behavior in the temperature range 12-26 K for the first time.

An unusual Pd(iii) oxidation state in the Pd–Cl chain complex with high thermal stability and electrical conductivity

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

Dalton Transactions ( Royal Society of Chemistry (RSC) ) 50 ( 5 ) 1614 - 1619 2021年 [査読有り]

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年12月 [査読有り]

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.

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