Horii Yoji

Faculty Division of Natural Sciences Research Group of ChemistryAssistant Professor
Last Updated :2025/04/14

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Profile Information

  • Name (Japanese)

    Horii

  • Name (Kana)

    Yoji

Research Areas

  • Natural sciences, Bio-, chemical, and soft-matter physics

Research History

  • Apr. 2025 - Present, Kagawa University, Faculty of Engineering and Design, Japan
  • Apr. 2020 - Mar. 2025, Nara Women's University, 助教
  • Sep. 2019 - Mar. 2020, 東北大学材料科学高等研究所, 助教
  • May 2019 - Sep. 2019, Tohoku University, 技術補佐員
  • Apr. 2017 - Mar. 2019, 大阪大学大学院理学研究科附属構造熱科学研究センター, 特任研究員
  • Apr. 2014 - Mar. 2017, 東北大学大学院理学研究科, 日本学術振興会特別研究員

Education

  • Apr. 2014 - Mar. 2017, 東北大学大学院理学研究科化学専攻
  • Apr. 2012 - Mar. 2014, 東北大学大学院理学研究科化学専攻
  • Apr. 2008 - Mar. 2012, 東北大学理学部化学科

Teaching Experience

  • Apr. 2021 - Present
  • Apr. 2021 - Present
  • Oct. 2023 - Apr. 2024
  • Oct. 2023 - Mar. 2024
  • Apr. 2023 - Aug. 2023
  • Apr. 2020 - Mar. 2022

Professional Memberships

  • 日本熱測定学会
    May 2017 - Present
  • 日本化学会
    Feb. 2012 - Present
  • 錯体化学会
    2012 - Present

Academic Activities

  • 第60回熱測定討論会実行委員, Academic society etc, 織田 昌幸, 26 Sep. 2024 - 28 Sep. 2024
  • 熱測定学会誌「熱測定」編集委員, Peer review etc, Apr. 2022 - Mar. 2023
  • 第54回熱測定ワークショップ 温度制御のための電子回路作成講習会運営, Academic society etc, 21 Aug. 2018 - 22 Aug. 2018

■Ⅱ．研究活動実績

Published Papers

  • Refereed, Journal of the American Chemical Society, American Chemical Society (ACS), Anisotropy of Spin–Lattice Relaxation Time (T1) for Oxo-Vanadium(IV) and Nitrido Chromium(V) Porphyrins, Sandra S. Eaton; Tsutomu Yamabayashi; Yoji Horii; Masahiro Yamashita; Gareth R. Eaton, 12 Apr. 2025, Scientific journal, 10.1021/jacs.5c01962
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  • Refereed, Crystal Growth & Design, American Chemical Society (ACS), Distinctive Magnetic Relaxation Behavior of Ln(III) Single-Molecule Magnets with a Conducting Organic π Donor System, Nobuto Funakoshi; Masanori Wakizaka; Qingyun Wan; Yongbing Shen; Haitao Zhang; Hiroshi Ito; Hiroaki Iguchi; Ryuta Ishikawa; Yoji Horii; Brian K. Breedlove; Shinya Takaishi; Masahiro Yamashita, 06 Apr. 2025, Scientific journal, 10.1021/acs.cgd.5c00120
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  • Refereed, Angewandte Chemie International Edition, Wiley, First Encapsulation of Organometallic Single‐Molecule Magnet into Single‐Walled Carbon Nanotubes, Haitao Zhang; Ryo Nakanishi; Takefumi Yoshida; Masahiko Nishijima; Koji Harano; Yoji Horii; Masahiro Yamashita, An air‐sensitive DyCp3 (Cp− = cyclopentadienyl) single‐molecule magnet (SMM) complex (1) was encapsulated into single‐walled carbon nanotubes (SWCNTs) to construct hybrid materials that are resistant to moisture and oxygen. The hybrid materials with independent slow‐magnetic‐relaxing centers are expected to become a key component of the next generation of information process devices based on spintronics. The resilience to moisture and oxygen further broadens its manufacturing methods and application scenarios. Furthermore, upon encapsulation into SWCNTs, DyCp3 exhibited clear ac frequency dependence in the ac magnetic susceptibility at a zero‐dc field. This indicates that the guest molecule's slow magnetic relaxation properties are preserved, which is crucial and necessary to realize SMMs‐based quantum information processing, by allowing a sufficient time window for quantum gate operations. Our result exemplifies that encapsulation of air‐sensitive organometallic SMMs into SWCNTs enhances their chemical stability and their magnetic relaxation time at a zero‐dc magnetic field, which provides a novel method for their further applications., 16 Mar. 2025, Scientific journal, 10.1002/anie.202503979
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  • Refereed, Crystal Growth & Design, American Chemical Society (ACS), Lanthanide-Based Single-Molecule Magnets Derived from Lacunary Polyoxometalates, Kenta Hirakawa; Yoshihiro Sekine; Fumiya Kobayashi; Yoji Horii; Hikaru Zenno; Manabu Nakaya; Shinya Hayami, 13 Mar. 2025, Scientific journal, 10.1021/acs.cgd.5c00111
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  • Refereed, Inorganic chemistry, Spin-Crossover Transitions of Solid Solutions of FeII Complexes with Fluorine- and Chlorine-Substituted Schiff-Base Ligands, Hqsal5F and Hqsal5Cl., Shoichi Tatsumi; Hitomi Noda; Miyu Umeda; Takamasa Kagotani; Kunihisa Sugimoto; Takayoshi Kuroda-Sowa; Saho Tamayose; Yoji Horii; Hal Suzuki, Spin-crossover (SCO) transitions of solid solutions of FeII complexes coordinated with fluorine- and chlorine-substituted Schiff-base ligands, [FeII(qsal5F)x(qsal5Cl)2-x] (x = 0.0-2.0, qsal5X = 5-halogeno-N-(8'-quinolyl)-2-hydroxy-1-salicylaldimine), were investigated by magnetic, single-crystal X-ray diffraction, and heat-capacity measurements. The SCO transition temperature decreases from 310.5 to 148.8 K as x increases from 0.0 to 2.0. At 0.0 ≤ x ≤ 1.0, both ΔtrsH and ΔtrsS decrease with increasing x, whereas ΔtrsH slightly decreases but ΔtrsS is almost constant at 1.5 ≤ x ≤ 2.0, showing that the x-dependence of Ttrs is mainly caused by variation in ΔtrsH. The different trend at 0.0 ≤ x ≤ 1.0 and 1.5 ≤ x ≤ 2.0 is because of different crystal structures of the HS state (monoclinic at 0.0 ≤ x ≤ 1.0 and orthorhombic at 1.5 ≤ x ≤ 2.0). Density functional theory calculations reveal that the single-point energy in the HS state decreases with an increase in x, indicating that the decrease in ΔtrsH is partly caused by a molecular distortion induced by the partial replacement of halogen species. The molar heat capacity of the HS state decreases as x increases, showing that changes in vibrational motions also contribute to variation of ΔtrsH., 04 Mar. 2025, Scientific journal, True, 10.1021/acs.inorgchem.4c04959
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  • Not Refereed, American Chemical Society (ACS), Molecular thermal engine based on a highly flexible elastic crystal, Hinako Kato; Yoji Horii; Chiharu Watanabe; Toshiyuki Sasaki; Kouhei Ichiyanagi; Mariko Noguchi; Hiroki Fujimori; Taro Yamamoto; Hal Suzuki; Yuichi Hirai; Takahito Ohmura; Keigo Yano; Shotaro Hayashi; Takashi Kajiwara, Materials that exhibit actuation behaviour in response to external stimuli have a wide range of applications owing to their ability to convert input energy into mechanical work. Light and chemicals are common sources of input energy. However, actuation using thermal energy from ambient-temperature sources remains challenging. In this study, we introduce novel elastic crystals composed of dodecylated porphyrin molecules that exhibit high flexibility and deformation in response to temperature changes. When a crystal is loaded with a small weight and positioned between high- and low-temperature heat sources, it exhibited continuous, large, and rapid oscillations. These oscillations persisted for at least 160 h, corresponding to 3.9 million deformation cycles, as long as the temperature difference was maintained. This study presents the first example of a molecular crystal functioning as an engine that can extract kinetic energy from static and ambient-temperature sources., 09 Jan. 2025, Manuscript.pdf, Preprint, False, 10.26434/chemrxiv-2025-tpnjj
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  • Refereed, Dalton Transactions, Royal Society of Chemistry (RSC), Spin dynamics phenomena of a cerium(iii) double-decker complex induced by intramolecular electron transfer, Kana Kobayashi; Michiyuki Suzuki; Tetsu Sato; Yoji Horii; Takefumi Yoshida; Brian. K. Breedlove; Masahiro Yamashita; Keiichi Katoh, By applying the IET to the spin dynamics of Ce porphyrinoid-based complexes, it is possible to investigate the effects of dynamic disorder on SMM properties., 17 Apr. 2024, 53, 28, 11664, 11677, Scientific journal, 10.1039/d4dt00436a
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  • Refereed, Journal of Materials Chemistry C, Royal Society of Chemistry (RSC), Two-dimensional metal–organic nanosheets composed of single-molecule magnets: structural modulation and enhanced magnetism utilizing the steric hindrance effect, Ikumi Aratani; Yoji Horii; Yoshinori Kotani; Hitoshi Osawa; Hajime Tanida; Toshiaki Ina; Takeshi Watanabe; Yohko F. Yano; Akane Mizoguchi; Daisuke Takajo; Takashi Kajiwara, Tuning the bulkiness of the single-molecule magnet (SMM) alters the structures of SMM-nanosheets, which results in enhanced perpendicular magnetic anisotropy and SMM properties., 2024, 12, 2, 724, 735, Scientific journal, 10.1039/d3tc03360k
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  • Refereed, Chemistry – A European Journal, Wiley, Magnetic Relaxations of Chromium Nitride Porphyrinato Complexes Driven by the Anisotropic g‐Factor, Tsutomu Yamabayashi; Yoji Horii; Zhao‐Yang Li; Masahiro Yamashita, Abstract

    Molecule‐based magnetic materials are useful candidates as the spin qubit due to their long coherence time and high designability. The anisotropy of the g‐values of the metal complexes can be utilized to access the individual spin of the metal complexes, making it possible to achieve the scalable molecular spin qubit. For this goal, it is important to evaluate the effect of g‐value anisotropy on the magnetic relaxation behaviour. This study reports the slow magnetic relaxation behaviour of chromium nitride (CrN2+) porphyrinato complex (1), which is structurally and magnetically similar with the vanadyl (VO2+) porphyrinato complex (2) which is known as the excellent spin qubit. Detailed analyses for vibrational and dynamical magnetism of 1 and 2 revealed that g‐value anisotropy accelerates magnetic relaxations greater than the internal magnetic field from nuclear spin does. These results provide a design criterion for construction of multiple spin qubit based on g‐tensor engineering., 20 Nov. 2023, 30, 3, e202303082, Scientific journal, 10.1002/chem.202303082
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  • Refereed, European Journal of Inorganic Chemistry, Wiley, Slow Magnetic Relaxation of Ni(III) Complexes toward Molecular Spin Qubits, Keiga Toshima; Tetsu Sato; Yoji Horii; Kazunobu Sato; Kenji Sugisaki; B. K. Breedlove; Shinya Takaishi; Zhao‐Yang Li; Masahiro Yamashita, Abstract

    Molecule‐based magnetic materials are promising candidates for molecular spin qubits, which utilize spin relaxation behavior. Various kinds of transition metal complexes with S=1/2 have been reported to act as spin qubits with long spin‐spin relaxation times (T2). However, the spin qubit properties of low‐spin Ni(III) complexes are not as well known since Ni(III) compounds are often unstable. We report here the slow magnetic relaxation behavior and T2 values for three kinds of low‐spin Ni(III) based complexes with S=1/2 under magnetically diluted conditions. [Ni(cyclam)X2]Y (cyclam=1,4,8,11‐tetraazacyclotetradecane) with octahedral structures and [Ni(mnt)2]− (mnt=maleonitriledithiolate) with a square‐planar structure underwent slow magnetic relaxations in the presence of a dc magnetic bias field. From electron spin resonance (ESR) spectroscopy, the Ni(III) complexes exhibited observable T2, indicating that Ni(III) complexes are promising candidates for use as molecule‐based spin qubits., 04 May 2023, 26, 19, e202300125, Scientific journal, 10.1002/ejic.202300125
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  • Refereed, The Journal of Physical Chemistry C, American Chemical Society (ACS), Slow Magnetic Relaxation of Linear Trinuclear M(II)–Gd(III)–M(II) Complexes with D3 Point Group Symmetry (M(II) = Zn(II) and Mg(II)), Yuka Masuda; Shiomi Sakata; Saori Kayahara; Natsumi Irie; Maiko Kofu; Yohei Kono; Toshiro Sakakibara; Yoji Horii; Takashi Kajiwara, 06 Feb. 2023, 127, 6, 3295, 3306, Scientific journal, 10.1021/acs.jpcc.2c08323
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  • Chemical Communications, Royal Society of Chemistry (RSC), Molecular elastic crystals exhibiting slow magnetic relaxations, Hinako Kato; Yoji Horii; Mariko Noguchi; Hiroki Fujimori; Takashi Kajiwara, Elastic crystals exhibiting slow magnetic relaxation behaviour were constructed by combining alkyl-substituted porphyrins and copper(ii) ions., 2023, 59, 98, 14587, 14590, Scientific journal, 10.1039/d3cc04770a
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  • Refereed, Journal of Materials Chemistry C, Royal Society of Chemistry (RSC), Construction of a two-dimensional metal-organic framework with a perpendicular magnetic anisotropy composed of single-molecule magnets, Ikumi Aratani; Yoji Horii; Daisuke Takajo; Yoshinori Kotani; Hitoshi Osawa; Takashi Kajiwara, The use of single-molecule magnets (SMMs) as memory devices can dramatically increase information storage capacity. However, a regular array of SMMs needs to be constructed on a substrate to access..., 2023, 11, 6, 2082, 2088, Scientific journal, 10.1039/d2tc04963e
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  • Refereed, ChemPhysChem, Wiley, 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, Abstract

    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] ⋅ 12H2O (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., 23 Nov. 2022, 24, 4, e202200618, Scientific journal, 10.1002/cphc.202200618
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  • Refereed, ACS Applied Polymer Materials, American Chemical Society (ACS), Defect-Assisted High Anion Conductivity in Diethyldimethylammonium d-Camphorsulfonate Plastic Crystal: A Size Effect of Target Ions, Xue Lan; Wenjing Sun; Xin Wang; Wei Xu; Yoji Horii; Jiandang Liu; Hongjun Zhang; Bangjiao Ye; Tiancheng Mu; Xiaozheng Lan, 07 Nov. 2022, 4, 12, 9368, 9377, Scientific journal, 10.1021/acsapm.2c01616
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  • Refereed, ChemPhysChem, Wiley, Benzenetriimide‐Based Molecular Conductor with Antiferro‐ to Ferromagnetic Switching Induced by Structural Change of π‐stacked Array, Shohei Koyama; Yoji Horii; Tetsu Sato; Shinya Takaishi; Norihisa Hoshino; Tomoyuki Akutagawa; Hiroaki Iguchi, Abstract

    Benzenetriimide (BTI) is a promising building block for materials chemistry due to its characteristic 3‐fold symmetry and redox properties, whereas little is known about its conductive and magnetic properties. In this study, we synthesized three charge‐transfer complexes based on N,N’,N’’‐trimethylbenzenetriimide (BTI‐Me). One of the complexes contains isolated dimers of BTI‐Me radical anion (BTI‐Me⋅−), while the other two have the infinite π‐stacked array of BTI‐Me with the formal charge of −0.5. The latter two complexes did not show metallic behavior but showed semiconducting behavior probably due to the characteristic insulation in one‐dimensional electron system, so‐called charge ordering and dimer‐Mott insulation. The magnetic susceptibility of the complex in dimer‐Mott state exhibits an unusual transition from antiferromagnetic to ferromagnetic spin states with the hysteresis loop of 15 K derived from the structural phase transition around 130 K. These properties were also supported by DFT calculations., 21 Jul. 2022, 23, 19, e202200322, Scientific journal, 10.1002/cphc.202200322
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  • Refereed, Dalton Transactions, Royal Society of Chemistry (RSC), Comparison between DySc2N@C80 and Dy2ScN@C80 single-molecule magnetic metallofullerenes encapsulated in single-wall carbon nanotubes, Satoshi Ito; Ryo Nakanishi; Keiichi Katoh; Brian K. Breedlove; Tetsu Sato; Zhao-Yang Li; Yoji Horii; Masanori Wakizaka; Masahiro Yamashita, The quantum tunneling mechanism of DySc2N@C80 and Dy2ScN@C80 in single-walled carbon nanotubes was revealed to be tuned in opposite ways., 25 Mar. 2022, 51, 16, 6339, 6344, Scientific journal, True, 10.1039/d2dt00524g
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  • Refereed, Bulletin of the Chemical Society of Japan, The Chemical Society of Japan, 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, 10 Feb. 2022, 95, 3, 513, 521, Scientific journal, 10.1246/bcsj.20210429
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  • Refereed, Chemical Society Reviews, Royal Society of Chemistry (RSC), Rare-earth based tetrapyrrolic sandwiches: chemistry, materials and applications, Alexander G. Martynov; Yoji Horii; Keiichi Katoh; Yongzhong Bian; Jianzhuang Jiang; Masahiro Yamashita; Yulia G. Gorbunova, This review summarises advances in chemistry of tetrapyrrole sandwiches with rare earth elements and highlights the current state of their use in single-molecule magnetism, organic field-effect transistors, conducting materials and nonlinear optics., 2022, 51, 22, 9262, 9339, Scientific journal, 10.1039/d2cs00559j
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  • Refereed, Inorganic Chemistry Frontiers, Royal Society of Chemistry (RSC), Solid polymorphism and dynamic magnetic properties of a 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; Zhao-Yang Li; Masahiro Yamashita, Phase stabilisation elongates spin–lattice relaxation times., 2022, 9, 23, 6271, 6278, Scientific journal, 10.1039/d2qi01607a
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  • Refereed, Dalton Transactions, Royal Society of Chemistry (RSC), Structural, magnetic and theoretical analyses of anionic and cationic phthalocyaninato-terbium(iii) double-decker complexes: magnetic relaxation via higher ligand-field sublevels enhanced by oxidation, Yoji Horii; Marko Damjanović; Keiichi Katoh; Masahiro Yamashita,

    Ligand oxidation of single-molecule magnets enhances magnetic relaxations via higher energy levels.

    , 2021, 50, 28, 9719, 9724, Scientific journal, 10.1039/d1dt00775k
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  • Refereed, Physical Chemistry Chemical Physics, Royal Society of Chemistry (RSC), Dynamics and magnetic properties of NO molecules encapsulated in open-cage fullerene derivatives evidenced by low temperature heat capacity, Yoji Horii; Hal Suzuki; Yuji Miyazaki; Motohiro Nakano; Shota Hasegawa; Yoshifumi Hashikawa; Yasujiro Murata,

    Heat capacity analyses revealed dynamics and magnetic anisotropy of NO molecules confined in molecular cages.

    , 2021, 23, 17, 10251, 10256, Scientific journal, 10.1039/d1cp00482d
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  • Refereed, Chemistry – A European Journal, Wiley, Highly Oxidized States of Phthalocyaninato Terbium(III) Multiple‐Decker Complexes Showing Structural Deformations, Biradical Properties and Decreases in Magnetic Anisotropy, Yoji Horii; Marko Damjanović; M. R. Ajayakumar; Keiichi Katoh; Yasutaka Kitagawa; Liviu Chibotaru; Liviu Ungur; Marta Mas‐Torrent; Wolfgang Wernsdorfer; Brian K. Breedlove; Markus Enders; Jaume Veciana; Masahiro Yamashita, Abstract

    Presented here is a comprehensive study of highly oxidized multiple‐decker complexes composed of TbIII and CdII ions and two to five phthalocyaninato ligands, which are stabilized by electron‐donating n‐butoxy groups. From X‐ray structural analyses, all the complexes become axially compressed upon ligand oxidation, resulting in bowl‐shaped distortions of the ligands. In addition, unusual coexistence of square antiprism and square prism geometries around metal ions was observed in +4e charged species. From paramagnetic 1H NMR studies on the resulting series of triple, quadruple and quintuple‐decker complexes, ligand oxidation leads to a decrease in the magnetic anisotropy, as predicted from theoretical calculations. Unusual paramagnetic shifts were observed in the spectra of the +2e charged quadruple and quintuple‐decker complexes, indicating that those two species are actually unexpected triplet biradicals. Magnetic measurements revealed that the series of complexes show single‐molecule magnet properties, which are controlled by the multi‐step redox induced structural changes., 18 Jun. 2020, 26, 39, 8621, 8630, Scientific journal, 10.1002/chem.202001365
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  • Refereed, Chemistry – A European Journal, Wiley, Coexistence of Spin–Lattice Relaxation and Phonon‐Bottleneck Processes in GdIII–Phthlocyaninato Triple‐Decker Complexes under Highly Diluted Conditions, Yoji Horii; Keiichi Katoh; Yuji Miyazaki; Marko Damjanović; Tetsu Sato; Liviu Ungur; Liviu F. Chibotaru; Brian K. Breedlove; Motohiro Nakano; Wolfgang Wernsdorfer; Masahiro Yamashita, Abstract

    Gd3+ complexes have been shown to undergo unusual slow magnetic relaxation processes similar to those of single‐molecule magnets (SMMs), even though Gd3+ does not exhibit strong magnetic anisotropy. To reveal the origin of the slow magnetic relaxation of Gd3+ complexes, we have investigated the magnetic properties and heat capacities of two Gd3+‐phthalocyaninato triple‐decker complexes, one of which has intramolecular Gd3+–Gd3+ interactions and the other does not. It was found that the Gd3+–Gd3+ interactions accelerate the magnetic relaxation processes. In addition, magnetically diluted samples, prepared by doping a small amount of the Gd3+ complexes into a large amount of diamagnetic Y3+ complexes, underwent dual magnetic relaxation processes. A detailed dynamic magnetic analysis revealed that the coexistence of spin–lattice relaxation and phonon‐bottleneck processes is the origin of the dual magnetic relaxation processes., 05 Jun. 2020, 26, 36, 8076, 8082, Scientific journal, 10.1002/chem.201905796
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  • Refereed, Inorganic Chemistry, American Chemical Society (ACS), Solid-State Spin Equilibrium of Ni(cyclam)2 Complex: Magnetostructural Correlations in Two Polymorphs, Yoji Horii; Yuki Kanegae; Kiyonori Takahashi; Akira Fuyuhiro; Mariko Noguchi; Hal Suzuki; Motohiro Nakano, 31 Mar. 2020, 59, 8, 5418, 5423, Scientific journal, 10.1021/acs.inorgchem.9b03735
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  • Refereed, Chemical Communications, Royal Society of Chemistry (RSC), Cocrystals of Li+ encapsulated fullerenes and Tb(iii) double-decker single molecule magnet in a quasi-kagome lattice, Hikaru Iwami; Junfei Xing; Ryo Nakanishi; Yoji Horii; Keiichi Katoh; Brian K. Breedlove; Kazuhiko Kawachi; Yasuhiko Kasama; Eunsang Kwon; Masahiro Yamashita,

    Cocrystallization of a lithium ion encapsulated fullerene with a terbium(iii) phthalocyaninato porphyrinato double-decker single-molecule magnet results in a quasi-kagome lattice packing showing ferromagnetic spin arrangement.

    , 2020, 56, 84, 12785, 12788, Scientific journal, 10.1039/d0cc04349d
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  • Refereed, Chemistry – A European Journal, Wiley, Simultaneous Spin‐Crossover Transition and Conductivity Switching in a Dinuclear Iron(II) Coordination Compound Based on 7,7′,8,8′‐Tetracyano‐p‐quinodimethane, Ryuta Ishikawa; Shuya Ueno; Shoei Nifuku; Yoji Horii; Hiroaki Iguchi; Yuji Miyazaki; Motohiro Nakano; Shinya Hayami; Shohei Kumagai; Keiichi Katoh; Zhao‐Yang Li; Masahiro Yamashita; Satoshi Kawata, Abstract

    The reaction of Fe(OAc)2 and Hbpypz with neutral TCNQ results in the formation of [Fe2(bpypz)2(TCNQ)2](TCNQ)2 (1), in which Hbpypz=3,5‐bis(2‐pyridyl)pyrazole and TCNQ=7,7′,8,8′‐tetracyano‐p‐quinodimethane. Crystal packing of 1 with uncoordinated TCNQ and π–π stacking of bpypz− ligands produces an extended two‐dimensional supramolecular coordination assembly. Temperature dependence of the dc magnetic susceptibility and heat capacity measurements indicate that 1 undergoes an abrupt spin crossover (SCO) with thermal spin transition temperatures of 339 and 337 K for the heating and cooling modes, respectively, resulting in a thermal hysteresis of 2 K. Remarkably, the temperature dependence of dc electrical transport exhibits a transition that coincides with thermal SCO, demonstrating the thermally induced magnetic and electrical bistability of 1, strongly correlating magnetism with electrical conductivity. This outstanding feature leads to thermally induced simultaneous switching of magnetism and electrical conductivity and a magnetoresistance effect., 10 Dec. 2019, 26, 6, 1278, 1285, Scientific journal, 10.1002/chem.201903934
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  • Refereed, CrystEngComm, Royal Society of Chemistry (RSC), Versatile coordination architectures of products generated by the in situ reaction of a doubly bis(2-pyridyl)pyrazolate bridged dinuclear copper(ii) complex with tetracyanoethylene, Ryuta Ishikawa; Shunya Ueno; Yumi Hamatake; Yoji Horii; Yuji Miyazaki; Motohiro Nakano; Takeshi Noda; Mikoto Uematsu; Satoshi Kawata,

    Reaction of doubly bpypz− bridged Cu(ii) dinuclear complex and TCNE gave three versatile coordination assemblies with TCNE solvolysis derivatives, depending on reaction solvents.

    , 13 Feb. 2019, 21, 12, 1886, 1894, Scientific journal, 10.1039/c9ce00036d
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  • Refereed, Chemistry – A European Journal, Wiley, Detailed Analysis of the Crystal Structures and Magnetic Properties of a Dysprosium(III) Phthalocyaninato Sextuple‐Decker Complex: Weak f–f Interactions Suppress Magnetic Relaxation, Yoji Horii; Keiichi Katoh; Kunihisa Sugimoto; Ryo Nakanishi; Brian K. Breedlove; Masahiro Yamashita, Abstract

    In the research field of single‐molecule magnets (SMMs), lanthanoid–lanthanoid interactions, so‐called f–f interactions, are known to affect the SMM properties, although their magnitudes are small. In this article, an SMM with very weak f–f interactions is reported, and the effects of the interactions on the SMM properties are discussed. X‐ray structural analysis of the DyIII‐CdII‐phthalocyaninato sextuple‐decker complex (Dy2Cd3) reveals that the intramolecular Dy−Dy length in Dy2Cd3 is more than 13 Å, which is longer than the intermolecular Dy−Dy length. Even though the two DyIII ions are far apart, intermolecular ferromagnetic dipole–dipole interactions are observed in Dy2Cd3. From detailed analysis of ac magnetic susceptibilities, quantum tunneling of the magnetization (QTM) in Dy2Cd3 is partially suppressed owing to the existence of very weak Dy−Dy interactions. Our results show that even very weak Dy−Dy interactions act as a dipolar bias, suppressing QTM., 04 Feb. 2019, 25, 12, 3098, 3104, Scientific journal, 10.1002/chem.201805368
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  • Refereed, Chemistry - A European Journal, Wiley-VCH Verlag, Supramolecular Approach for Enhancing Single-Molecule Magnet Properties of Terbium(III)-Phthalocyaninato Double-Decker Complexes with Crown Moieties, Yoji Horii; Shuhei Kishiue; Marko Damjanović; Keiichi Katoh; Brian K. Breedlove; Markus Enders; Masahiro Yamashita, A TbIII-phthalocyaninato double-decker ([1]0) single-molecule magnet (SMM) having four 15-crown-5 moieties in one of the ligands was synthesized, and its dimerization and magnetic properties were studied in an attempt to utilize the supramolecular aggregation for enhancing the SMM properties. Aggregation of [1]0 to form [12K4]4+ in the presence of K+ ions was studied by using UV/Vis-NIR absorption and NMR spectroscopies. For the magnetic measurements, [1]0 and [12K4]4+ were dispersed in poly(methyl methacrylate) (PMMA). UV/Vis-NIR absorption measurements on the PMMA dispersed samples were used to track the formation of [12K4]4+. Direct current (DC) magnetic susceptibility measurements revealed that there were ferromagnetic Tb–Tb interactions in [12K4]4+, whereas there was no indication of ferromagnetic interactions in [1]0. Upon the formation of [12K4]4+ from [1]0 and K+ ions, the temperature at which the magnetic hysteresis occurred increased from 7 to 15 K. In addition, the area of magnetic hysteresis became larger for [12K4]4+, meaning that SMM properties of [12K4]4+ are superior to those of [1]0. Alternating current (AC) magnetic measurements were used to confirm this observation. Magnetic relaxation times at 2 K increased 1000-fold upon dimerization of [1]0 to [12K4]4+, demonstrating the effectiveness of using K+ ions to induce dimer formation for the improvement of the SMM properties., 20 Mar. 2018, 24, 17, 4320, 4327, Scientific journal, 10.1002/chem.201705378
    DOI URL
  • Refereed, Inorganic Chemistry, American Chemical Society, Changing Single-Molecule Magnet Properties of a Windmill-Like Distorted Terbium(III) α-Butoxy-Substituted Phthalocyaninato Double-Decker Complex by Protonation/Deprotonation, Yoji Horii; Yusuke Horie; Keiichi Katoh; Brian K. Breedlove; Masahiro Yamashita, Synthesis, structures, and magnetic properties of α-butoxy-substituted phthalocyaninato double-decker complexes Tb(α-obPc)2 (1-) (α-obPc: dianion of 1,4,8,11,15,18,22,25-octa(n-butoxy)phthalocyaninato) with protonated (1H), deprotonated (1[HDBU]), and diprotonated forms (1H2+) are discussed. X-ray analysis was used to confirm the position of the proton in 1H, and it was revealed that the protonation induced asymmetric distortion in 1H. In contrast, 1[HDBU] was distorted in a highly symmetric windmill-like fashion. 1H is arranged in a slipped column array in the crystal packing, whereas 1[HDBU] is arranged in a one-dimensional fashion, in which the magnetic easy axes of 1[HDBU] lie along the same line. From direct-current (dc) magnetic measurements, ferromagnetic Tb-Tb interactions occur in both 1H and 1[HDBU], and magnetic hysteresis was observed. However, the area of the magnetic hysteresis in 1[HDBU] is larger than that in 1H, meaning that magnetic relaxation time (τ) is longer in 1[HDBU]. In addition, the results of alternating-current magnetic measurements in a zero dc magnetic field indicate that τ of 1[HDBU] is longer as compared to 1H. In other words, protonation/deprotonation affects not only the molecular structures and crystal packing but also the single-molecule magnet properties., 16 Jan. 2018, 57, 2, 565, 574, Scientific journal, 10.1021/acs.inorgchem.7b02124
    DOI URL
  • Refereed, Materials, MDPI AG, Metal-Organic Framework of Lanthanoid Dinuclear Clusters Undergoes Slow Magnetic Relaxation, Hikaru Iwami; Ryo Nakanishi; Yoji Horii; Keiichi Katoh; Brian Breedlove; Masahiro Yamashita, 20 Jan. 2017, 10, 1, 81, 81, Scientific journal, 10.3390/ma10010081
    DOI URL
  • Refereed, Chemical Communications, Royal Society of Chemistry (RSC), Elongation of magnetic relaxation times in a single-molecule magnet through intermetallic interactions: a clamshell-type dinuclear terbium(iii)-phthalocynaninato quadruple-decker complex, Yoji Horii; Keiichi Katoh; Brian K. Breedlove; Masahiro Yamashita,

    Clamshell-type terbium(iii)-phthalocyaninato quadruple-decker complex was synthesized. Magnetic measurements revealed that Tb–Tb interactions caused an increase in the magnetic relaxation time.

    , 2017, 53, 61, 8561, 8564, Scientific journal, 10.1039/c7cc03553e
    DOI URL
  • Refereed, Inorganic Chemistry, American Chemical Society (ACS), Weak DyIII–DyIII Interactions in DyIII–Phthalocyaninato Multiple-Decker Single-Molecule Magnets Effectively Suppress Magnetic Relaxation, Yoji Horii; Keiichi Katoh; Goulven Cosquer; Brian K. Breedlove; Masahiro Yamashita, 09 Nov. 2016, 55, 22, 11782, 11790, Scientific journal, 10.1021/acs.inorgchem.6b01870
    DOI URL
  • Refereed, ChemPhysChem, Wiley, How Ions Arrange in Solution: Detailed Insight from NMR Spectroscopy of Paramagnetic Ion Pairs, Marko Damjanović; Takaumi Morita; Yoji Horii; Keiichi Katoh; Masahiro Yamashita; Markus Enders, Abstract

    Ion pairing between the paramagnetic anion [Tb(obPc)2]− (obPc=2,3,9,10,16,17,23,24‐octabutoxyphthalocyaninato), which has a very large magnetic anisotropy, with various diamagnetic counterions [P(Ph)4]+ (1 a), [As(Ph)4]+ (1 b), bis(triphenylphosphine)iminium ([PPN]+, 1 c) and tetra‐n‐butylammonium ([TBA]+, 1 d) was studied by means of 1H, 13C, 14N, and 31P NMR spectroscopy in solution at various temperatures. The influence of the paramagnetic anion on the NMR spectroscopy properties of the diamagnetic cations allowed a detailed insight into the distances and relative orientations of the paired ions. Isotropic tumbling models for the description of the quaternary cations are inaccurate, particularly for [TBA]+ with its flexible butyl chains. The effects of temperature and concentration were also assessed. The advantage of this technique is that relatively large distances and the orientation between molecules or ions in solution can be studied., Sep. 2016, 17, 21, 3423, 3429, Scientific journal, 10.1002/cphc.201600804
    DOI URL
  • Refereed, European Journal of Inorganic Chemistry, Wiley, Field‐Induced Single‐Ion Magnetism Based on Spin‐Phonon Relaxation in a Distorted Octahedral High‐Spin Cobalt(II) Complex, Ryuta Ishikawa; Yoji Horii; Ryo Nakanishi; Shunya Ueno; Brian K. Breedlove; Masahiro Yamashita; Satoshi Kawata, The six‐coordinate mononuclear high‐spin cobalt(II) complex [Co(bpy)2(ClAn)]·EtOH (1; bpy = 2,2′‐bipyridine, ClAn2– = chloranilate) and its magnetically diluted analogue [Co0.1Zn0.9(bpy)2(ClAn)]·EtOH (3), in which the CoII centres of 1 are partially diluted with the magnetically inactive ZnII centres of [Zn(bpy)2(ClAn)]·EtOH (2) as a diamagnetic matrix, exhibited slow magnetic relaxation in applied direct‐current (DC) magnetic fields. Fits of the DC magnetic data indicate that this new field‐induced single‐ion magnet possesses large positive axial and significant rhombic zero‐field splittings. The results of temperature‐dependent and DC‐magnetic‐field‐dependent alternating‐current magnetic measurements on 1 and 3, which is a field‐induced single‐ion magnet, agree with those from theoretical studies, and spin relaxation occurs through two‐phonon Raman and direct spin‐phonon bottleneck processes of Kramers ions., 15 Jun. 2016, 2016, 20, 3233, 3239, Scientific journal, 10.1002/ejic.201600481
    DOI URL
  • Refereed, Inorganic Chemistry, American Chemical Society (ACS), α-Substituted Bis(octabutoxyphthalocyaninato)Terbium(III) Double-Decker Complexes: Preparation and Study of Protonation by NMR and DFT, Marko Damjanović; Yusuke Horie; Takaumi Morita; Yoji Horii; Keiichi Katoh; Masahiro Yamashita; Markus Enders, 09 Dec. 2015, 54, 24, 11986, 11992, Scientific journal, 10.1021/acs.inorgchem.5b02391
    DOI URL
  • Refereed, Inorganic Chemistry, American Chemical Society (ACS), Effects of f–f Interactions on the Single-Molecule Magnet Properties of Terbium(III)–Phthalocyaninato Quintuple-Decker Complexes, Yoji Horii; Keiichi Katoh; Nobuhiro Yasuda; Brian K. Breedlove; Masahiro Yamashita, 23 Mar. 2015, 54, 7, 3297, 3305, Scientific journal, 10.1021/ic502951t
    DOI URL
  • Refereed, Dalton Transactions, Royal Society of Chemistry (RSC), Effect of f–f interactions on quantum tunnelling of the magnetization: mono- and dinuclear Dy(iii) phthalocyaninato triple-decker single-molecule magnets with the same octacoordination environment, Keiichi Katoh; Rina Asano; Akira Miura; Yoji Horii; Takaumi Morita; Brian K. Breedlove; Masahiro Yamashita, 2014, 43, 21, 7716, 7716, Scientific journal, 10.1039/c4dt00042k
    DOI URL
  • Refereed, Dalton Transactions, Royal Society of Chemistry (RSC), Multiple-decker phthalocyaninato dinuclear lanthanoid(iii) single-molecule magnets with dual-magnetic relaxation processes, Keiichi Katoh; Yoji Horii; Nobuhiro Yasuda; Wolfgang Wernsdorfer; Koshiro Toriumi; Brian K. Breedlove; Masahiro Yamashita, 2012, 41, 44, 13582, 13582, Scientific journal, 10.1039/c2dt31400b
    DOI URL

MISC

  • Not Refereed, Mar. 2024, 77, 3, 212, 213, Introduction scientific journal
  • Not Refereed, Jan. 2024, 79, 1, 62, 63, Introduction commerce magazine
  • Refereed, 熱測定, Suppression of Quantum Tunneling Effect by Dimerization of Single-Molecule Magnets, 堀井洋司; 堀井洋司, Jun. 2020, 47, 3, Introduction scientific journal
  • Not Refereed, 月刊化学, 進化を続ける次世代型ナノ分子磁石-高温動作する単分子磁石を目指して!!, 堀井洋司; 加藤恵一; 山下正廣, 2014, 1, 45, 50, Introduction other

Presentations

  • 28 Sep. 2024
  • 28 Sep. 2024
  • 27 Sep. 2024
  • 27 Sep. 2024
  • 27 Sep. 2024
  • 27 Sep. 2024
  • 27 Sep. 2024
  • 20 Sep. 2024
  • 20 Sep. 2024
  • 20 Sep. 2024
  • 18 Sep. 2024
  • 18 Sep. 2024
  • 18 Sep. 2024
  • 18 Sep. 2024
  • Public discourse, 26 Mar. 2024
  • Poster presentation, 20 Mar. 2024
  • Poster presentation, 19 Mar. 2024
  • Modulation of magnetic relaxation behaviour of metal complexes by changes in the surroundings, Oral presentation, 01 Aug. 2023
  • Elastic Porphyrin Crystal: Softening upon Cooling and Control of the Mechanical Properties by Co-crystalization, Poster presentation, 31 Jul. 2023
  • Synthesis of hydroxy substituted single-molecule magnets for construction of an electroconductive magnetic nanosheet, Poster presentation, 31 Jul. 2023
  • Poster presentation, 24 Mar. 2023
  • 22 Mar. 2023
  • 22 Mar. 2023
  • Yoji Horii; Ikumi Aratani; Takashi Kajiwara, 2nd Asian Conference on Molecular Magnetism, Structural and Magnetic Study for Two-dimensional Metal-Organic Frameworks Composed of Single-Molecule Magnets, 09 Dec. 2022
  • Yoji Horii; Ikumi Aratani; Daisuke Takajo; Takashi Kajiwara, The 73rd Yamada Conference, Two dimensional MOFs composed of SMMs, 08 Oct. 2022
  • Temperature-dependent elasticity of an elastic crystal composed of a porphyrin: suppression of curing upon cocrystallization with the metalloporphyrin, Sep. 2022, 26 Sep. 2022 - 28 Sep. 2022
  • 26 Sep. 2022 - 28 Sep. 2022
  • Yoji Horii; Ikumi Aratani; Daisuke Takajo; Takashi Kajiwara, 8th Asian Conference on Coordination Chemistry, Tow-dimensional MOFs Composed of Single-Molecule Magnets, 11 Aug. 2022
  • Mar. 2022, 23 Mar. 2022 - 26 Mar. 2022
  • 16 Sep. 2021
  • Yoji Horii; Keiichi Katoh; Masahiro Yamashita, 17th International Conference on Molecule Based Magnets, Triplet Biradical States in Oxidized Form of Phthalocyaninato-Lanthanoid(III) Multiple-Decker Complexes, 16 Jun. 2021
  • Triplet biradical states of phthalocyaninato-terbium(III) multiple-decker complexes captured by paramagnetic NMR analyses, 10 Mar. 2021
  • Comprehensive studies for structural and magnetic properties of terbium(III) phthalocyaninato multiple-decker complexes in high-valence states, 21 Sep. 2019
  • Correlation between Structures and Spin Crossover Behaviors in Two Kinds of Crystal Polymorphs of [Ni(cyclam)I2] Complex, 01 Sep. 2018
  • Magnetic dilution effects in the slow magnetic relaxation of a phthalocyaninato Gd(III) triple-decker complex, 30 Jul. 2018
  • Structures and magnetic properties of phthalocyaninato multipledecker complexes in high oxidation state, 19 Mar. 2017
  • Magnetic properties of stable terbium(III)-phthalocyaninato multiple-decker complexes in high valence states, 10 Sep. 2016
  • Magnetic properties of multi-oxidation species of terbium(III)-phthalocyaninato multiple-decker complexes, 04 Sep. 2016
  • Magnetic properties of stable terbium(III)-phthalocyaninato multiple-decker complexesin high valence states, 03 Jul. 2016
  • 27 Mar. 2016
  • Magnetic properties of dysprosium(III)-yttrium(III) phthalocyaninato quadruple-decker complexes, 15 Dec. 2015
  • 26 Mar. 2015
  • Magnetic behaviors of multiple-decker phthalocyaninato terbium (III) SMM complexes at relatively high temperature, 15 Oct. 2014
  • Clamshell型フタロシアニンを用いたクアドラプルデッカー型テルビウム錯体の合成と磁気特性の合成, 19 Sep. 2014
  • Magnetic Behavior of Multiple-Decker Phthalocyaninato Terbium(III) SMM Complexes at Relatively High Temperature, 05 Jul. 2014
  • Dysprosium-phthalocyaninato multiple-decker complexes: Relationship between structures and magnetic properties, 03 Nov. 2013
  • 02 Nov. 2013
  • The 13th International Conference on Molecule-based Magnets (ICMM2012), Magnetic Properties of Tb(III)-Cd(II)-Phthalocyaninato Complexes, 08 Oct. 2012
  • 21 Sep. 2012
  • 17 Sep. 2011
  • Poster presentation, 22 Mar. 2023 - 25 Mar. 2023
  • Poster presentation, 22 Mar. 2023 - 25 Mar. 2023
  • Poster presentation, 22 Mar. 2023 - 25 Mar. 2023
  • Oral presentation, 26 Sep. 2022 - 28 Sep. 2022
  • Poster presentation, 26 Sep. 2022 - 28 Sep. 2022
  • Oral presentation
  • Invited oral presentation
  • Oral presentation
  • Poster presentation, 23 Mar. 2022 - 26 Mar. 2022
  • Poster presentation, 16 Sep. 2021 - 19 Sep. 2021
  • Oral presentation, 14 Jun. 2021 - 18 Jun. 2021
  • Oral presentation, 07 Mar. 2021 - 10 Mar. 2021

Awards

  • The 15th International Conference on Molecule-Based Magnets：Poster Award, Sep. 2016, 36698189, rm:research_project_id
    対象リソースIRI
  • Sep. 2011

Research Projects

  • 基盤研究(C), Apr. 2023 - Mar. 2028, 23K04875, アルキル鎖導入に伴う分子弾性結晶の構築：力学特性の精密制御と複合物性化, 堀井 洋司, 日本学術振興会, 科学研究費助成事業, 奈良女子大学, 4810000, 3700000, 1110000, kaken
    対象リソースIRI
  • Dec. 2024, 気液界面を利用した単分子磁石薄膜の構築と分子スピントロニクスへの展開, カシオ科学振興財団, 第42回(令和6年度) 研究助成
  • Dec. 2024, 弾性・磁性・電気伝導性の物性複合化と化学ドーピングによる力学特性の精密制御, 公益財団法人マツダ財団, 第40回（2024年度）マツダ研究助成
  • 若手研究, 01 Apr. 2021 - 31 Mar. 2023, 21K14645, 両親媒性配位子を用いた裏表を有する薄膜状配位高分子の運動機能性と磁気特性, 堀井 洋司, 日本学術振興会, 科学研究費助成事業 若手研究, 奈良女子大学, 4680000, 3600000, 1080000, 本研究では、両親媒性を有する配位子を親水-疎水界面で反応させることで、裏表を有する新奇の二次元の金属有機骨格(MOF)を構築し、配位子のかさ高さとMOFの構造(1)、および磁気特性(2)の相関を明らかにした。
    (1)フタロシアニン(Pc)-ポルフィリン(Por)からなる２層積層型の単分子磁石錯体を配位子として用い、親水-疎水界面を利用することで２次元集積体を合成した。Por部位には、水相中の金属イオン(Pd2+)と反応可能なピリジル基(Py)を導入した。また、分子のかさ高さと薄膜の構造の相関について知見を得るため、フタロシアニン部位には種々の長さを有するアルコキシ鎖を導入した。
    Lamgmuir-Blodgett(LB)膜作成装置を用いて表面圧（π）vs. 分子面積(A)測定を測定したところ、金属イオン(Pd2+)存在下で分子１つ当たりの占める面積(A*)の上昇が観測されたことから、２次元集積体の形成を確認した。アルコキシ基の鎖長を長くするほどA*は大きくなったことから、配位子のかさ高さによって薄膜の構造に差異が生じることが明らかになった。また薄膜サンプルの粉末X線構造回折測定より、無置換Pcと比較して、アルコキシ基導入Pcからなる薄膜サンプルは低角側に新たな回折ピークを示すことを明らかにした。これは、アルコキシ基の導入前はPd(Py)4からなる密な集積構造を取る一方、アルコキシ基導入後ではPd(Py2)からなる疎な構造が形成されたことを示唆する結果である。
    (2)磁気測定により、薄膜形成後においても単分子磁石特性が保持されていることを確認した。さらに、アルコキシ鎖が長いほど単分子磁石特性が良いことを明らかにした。これは、鎖長延長によって薄膜内の分子同士が離れた結果、分子間の磁気的相互作用が抑制されることにより、単分子磁石特性が向上したことを示唆している。, kaken
    対象リソースIRI
  • Grant-in-Aid for Early-Career Scientists, 01 Apr. 2018 - 31 Mar. 2020, 18K14242, Verification of phase transition with chiral inversion in 2D aggregate of molecular rotors, Horii Yoji, Japan Society for the Promotion of Science, Grants-in-Aid for Scientific Research Grant-in-Aid for Early-Career Scientists, 4290000, 3300000, 990000, We synthesized a molecular composed of a rotor unit and a metal-binding site,which enabled us to construct a 2D aggregate of the molecular rotor by LB method in a presence of metal ions. The membrane structure of which thickness corresponded to the height of the rotor molecules was observed by using AFM measurements, indicating the formation of the target substance. UV-Vis absorption spectra before and after the reaction with metal ions are almost identical, indicating that the structure of the rotor was sustained. To observe the correlated motion of the molecular rotors, temperature dependent UV-Vis absorption measurements was conducted. However, no evidence of the phase transition induced by the motion of rotor was obtained., url
    対象リソースIRI
  • 特別研究員奨励費, 25 Apr. 2014 - 31 Mar. 2017, 14J02656, フタロシアニン多層積層型錯体を用いた分子デバイスの創出および新規物性の開拓, 堀井 洋司, 日本学術振興会, 科学研究費助成事業 特別研究員奨励費, 東北大学, 2800000, 2800000, 本年度は、フタロシアニン多層積層型錯体の構造と磁気物性の解明という観点から、１）フタロシアニン６層積層型錯体の結晶構造解明および２）フタロシアニン多層積層型錯体の酸化還元に伴う構造・磁気特性の変化の２つについて研究を行った。
    １）これまでの研究より、フタロシアニン多層積層型錯体が単分子磁石として振る舞い、積層数を変化させることで分子内の磁気的な相互作用の強弱を制御できることが知られている。本テーマでは、これまでの報告されている中で最も分子内磁気相互作用の弱い６層積層型錯体の合成および結晶構造解明に成功し、６層錯体内の磁性原子は1.3 nm以上離れた距離にあることを明らかにした。従来の単分子磁石研究では、1nm以上離れた磁性イオン間の相互作用は無視できるほど小さいと考えられていた。しかしながら、６層錯体の磁化率測定を行ったところ、1.3 nm以上離れた磁性イオン間にも強磁性的な相互作用が働いており、単分子磁石特性に影響を与えうることが明らかとなった。本研究は単分子磁石設計にも応用できることから、分子磁性分野において一石を投じる結果である。
    ２）フタロシアニン多層積層型錯体は拡張したπ共役系を有することから、多彩な酸化還元特性を示すことが明らかとなっている。これを単分子磁石特性と組み合わせることで、酸化還元に伴う磁気特性の制御が可能になると考えられる。以上の観点より、本テーマでは、フタロシアニン多層積層型錯体の高酸化状態における構造と磁気特性の解明を行った。結晶構造解析より、多層錯体は酸化に伴って分子を縦方向に圧縮するような変形を示すことを明らかにした。またこの構造変化に伴い、単分子磁石特性も大きく変化することを見出した。とくに４層・５層錯体では、これまでに報告されている中で最も多い５段階の磁気特性制御に成功した。, kaken
    対象リソースIRI

■Ⅲ．社会連携活動実績

１．公的団体の委員等（審議会、国家試験委員、他大学評価委員，科研費審査委員等）

  • 第６０回熱測定討論会 実行委員, Mar. 2024 - Present
  • 日本熱測定学会 「熱測定」誌 編集委員, Apr. 2022 - Mar. 2023