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Osamu Sato Last modified date:2023.11.22

Graduate School

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Academic Degree
Dr. Eng.
Country of degree conferring institution (Overseas)
Field of Specialization
Total Priod of education and research career in the foreign country
Research Interests
  • Development of photo-functional materials
    keyword : Photomagnetism, polarization switching, spin crossover, valence tautomerism, dynamic molecular crystal
    2005.04A reversible tuning and a persistent (irreversible) modification of physical properties by external stimuli are one of the main challenges in materials science. Especially, photo-control over the physical properties is important from the viewpoint of the practical application as well as the basic science. The photo-tunable compounds can be used future memory devices, optical switches and so on. Along this line, we are currently studying photo-tunable molecular magnets, valence tautomeric compounds, spin-crossover complexes and photonic crystals..
Academic Activities
1. Wei Huang, Shuqi Wu, Xiangwei Gu, Yao Li, Atsushi Okazawa, Norimichi Kojima, Shinya Hayami, Michael L. Baker, Peter Bencok, Mariko Noguchi, Yuji Miyazaki, Motohiro Nakano, Takumi Nakanishi, Shinji Kanegawa, Yuji Inagaki, Tatsuya Kawae, Gui-Lin Zhuang, Yoshihito Shiota, Kazunari Yoshizawa, Dayu Wu, Osamu Sato, Temperature dependence of spherical electron transfer in a nanosized [Fe14] complex, Nature communications, 10.1038/s41467-019-13279-y, 10, 5510, 2019.12, The study of transition metal clusters exhibiting fast electron hopping or delocalization remains challenging, because intermetallic communications mediated through bridging ligands are normally weak. Herein, we report the synthesis of a nanosized complex, [Fe(Tp)(CN)3]8[Fe(H2O)(DMSO)]6 (abbreviated as [Fe14], Tp−, hydrotris(pyrazolyl)borate; DMSO, dimethyl sulfoxide), which has a fluctuating valence due to two mobile d-electrons in its atomic layer shell. The rate of electron transfer of [Fe14] complex demonstrates the Arrhenius-type temperature dependence in the nanosized spheric surface, wherein high-spin centers are ferromagnetically coupled, producing an S = 14 ground state. The electron-hopping rate at room temperature is faster than the time scale of Mössbauer measurements (
2. Zi Shuo Yao, Hanxi Guan, Yoshihito Shiota, Chun Ting He, Xiao Lei Wang, Shu Qi Wu, Xiaoyan Zheng, Sheng Qun Su, Kazunari Yoshizawa, Xueqian Kong, Osamu Sato, Jun Tao, Giant anisotropic thermal expansion actuated by thermodynamically assisted reorientation of imidazoliums in a single crystal, Nature communications, 10.1038/s41467-019-12833-y, 10, 4805, 2019.10, Materials demonstrating unusual large positive and negative thermal expansion are fascinating for their potential applications as high-precision microscale actuators and thermal expansion compensators for normal solids. However, manipulating molecular motion to execute huge thermal expansion of materials remains a formidable challenge. Here, we report a single-crystal Cu(II) complex exhibiting giant thermal expansion actuated by collective reorientation of imidazoliums. The circular molecular cations, which are rotationally disordered at a high temperature and statically ordered at a low temperature, demonstrate significant reorientation in the molecular planes. Such atypical molecular motion, revealed by variable-temperature single crystal X-ray diffraction and solid-state NMR analyses, drives an exceptionally large positive thermal expansion and a negative thermal expansion in a perpendicular direction of the crystal. The consequent large shape change (~10%) of bulk material, with remarkable durability, suggests that this complex is a strong candidate as a microscale thermal actuating material..
3. Takumi Nakanishi, Yuta Hori, Hiroyasu Sato, Shu Qi Wu, Atsushi Okazawa, Norimichi Kojima, Takashi Yamamoto, Yasuaki Einaga, Shinya Hayami, Yusuke Horie, Hajime Okajima, Akira Sakamoto, Yoshihito Shiota, Kazunari Yoshizawa, Osamu Sato, Observation of Proton Transfer Coupled Spin Transition and Trapping of Photoinduced Metastable Proton Transfer State in an Fe(II) Complex, Journal of the American Chemical Society, 10.1021/jacs.9b07204, 141, 36, 14384-14393, 2019.09, An important technique to realize novel electron- A nd/or proton-based functionalities is to use a proton-electron coupling mechanism. When either a proton or electron is excited, the other one is modulated, producing synergistic functions. However, although compounds with proton-coupled electron transfer have been synthesized, crystalline molecular compounds that exhibit proton-transfer-coupled spin-transition (PCST) behavior have not been reported. Here, we report the first example of a PCST Fe(II) complex, wherein the proton lies on the N of hydrazone and pyridine moieties in the ligand at high-spin and low-spin Fe(II), respectively. When the Fe(II) complex is irradiated with light, intramolecular proton transfer occurs from pyridine to hydrazone in conjunction with the photoinduced spin transition via the PCST mechanism. Because the light-induced excited high-spin state is trapped at low temperatures in the Fe(II) complex- A phenomenon known as the light-induced excited-spin-state trapping effect-the light-induced proton-transfer state, wherein the proton lies on the N of hydrazone, is also trapped as a metastable state. The proton transfer was accomplished within 50 ps at 190 K. The bistable nature of the proton position, where the position can be switched by light irradiation, is useful for modulating proton-based functionalities in molecular devices..
4. Zi-Shuo Yao, Shu-Qi Wu,Yasutaka Kitagawa, Sheng-Qun Su,You-Gui Huang, Guo-Ling Li, Zhong-Hai Ni, Hiroyuki Nojiri, Yoshihito Shiota, Kazunari Yoshizawa, Soonchul Kang, Shinji Kanegawa, and Osamu Sato, Anisotropic Change in the Magnetic Susceptibility of a Dynamic Single Crystal of a Cobalt(II) Complex, Angewandte Chemie International Edition, 10.1002/anie.201606165, 56, 717-721, 2017.01.
5. Osamu Sato, Dynamic molecular crystals with switchable physical properties, NATURE CHEMISTRY, 10.1038/nchem.2547, 8, 7, 644-656, 2016.07.
6. Osamu Sato, Shinji Kanegawa, Kazunari Yoshizawa, Takashi Kamachi, Yoshihito Shiota, KANG SOONCHUL, SU Shengqun, YAO Zishuo, HUANG Yougui, Nobuaki Azuma, Yuji Miyazaki, Motohiro Nakano, Goro Murata, Sadamu Takeda, Assembling an alkyl rotor to access abrupt and reversible crystalline deformation of a cobalt(II) complex, Nature Commun., 10.1038/ncomms9810, 6, 2015.6.8810
Nature Communications 6, Article number: 8810 (2015), 2015.11.
7. 佐藤 治, 吉澤 一成, 塩田 淑仁, KANG SOONCHUL, Hui Zheng, Tao Liu, Shinji Kanegawa, 濱地 晃平, 杉本 邦久, 速水 真也, 美藤 正樹, 中村 哲也, 中野 元裕, Michael L. Baker, 野尻 浩之, Chunying Duan, A Ferromagnetically Coupled Fe42 Cyanide-Bridged Nanocage, Nature Commun., 10.1038/ncomms6955, 6, 5955 (2015), 2015.01.
8. Osamu Sato, Tao Liu, Shinya Hayami, KANG SOONCHUL, Shinji Kanegawa, Masaki Mito, Yoshihito Shiota, Kazunari Yoshizawa, A light-induced spin crossover actuated single-chain magnet, Nature Communications, 10.1039/C3DT51554K, 2013.11.
9. Osamu Sato, Photoswitchable Dynamic Magnetic Relaxation in a Well-Isolated {Fe2Co} Double-Zigzag , Angew. Chem. Int. Ed., 2012, 51, 5119-5123, 2012.04.
10. T. Liu, D.-P. Dong, S. Kanegawa, S. Kang, O. Sato, Y. Shiota, K. Yoshizawa, S. Hayami, S. , Reversible Electron Transfer in an {Fe2Co} Linear Trinuclear Complex induced by Thermally Treatment and Photoirraditaion, Angew. Chem. Int. Ed., 2012, 51, 4367-4370, 2012.03.
11. Tao Liu, Yan-Juan Zhang, S. Kanegawa and O. Sato, Water-Switching of Metal-to-Metal Charge Transfer Induced Spin Transition in a Microporous Framework, Angew. Chem. Int. Ed., 2010, 49, 8645-8648, 2010.11.
12. Tao Liu, Yan-Juan Zhang, Shinji Kanegawa and Osamu Sato , Photoinduced Metal-to-Metal Charge Transfer towards Single-Chain Magnet, J. Am. Chem. Soc., 2010, 132, 8250-8251, 2010.06.
13. Osamu Sato , An Electric Effect, Nature Chem., 2, 10-11, 2010.01.
14. Yan-Juan Zhang, Tao Liu, Shinji Kanegawa and Osamu Sato , Interconversion between a Nonporous Nanocluster and a Microporous Coordination Polymer Showing Selective Gas Adsorption, J. Am. Chem. Soc., 132, 912-913, 2010.01.
15. Y.-J. Zhang, T. Liu, S. Kanegawa, O. Sato, Reversible Single-Crystal-to-Single-Crystal Transformation from Achiral Anti- ferromagnetic Hexanuclears to a Chiral Ferrimagnetic Double Zigzag Chain, J. Am. Chem. Soc., , 2009.05.
16. Gergely Juhász, Ryotaro Matsuda, Shinji Kanegawa, Kaori Inoue, O. Sato, Kazunari Yoshizawa , Bistability of Magnetization without Spin-Transition in a High-Spin Cobalt(II) Complex due to Angular Momentum Quenching, J. Am. Chem. Soc., 131, 4560-4561, 2009.03.
17. D.Y. Wu, O. Sato, Y. Einaga, C.-Y. Duan, A Spin Crossover Cluster Exhibiting Mixed-Spin [Fe(II)hs2Fe(II)ls2] Structure and Synergy between Spin Transition and Magnetic Interaction, Angew. Chem. Int. Ed., 48, 1475-1478, 2009.02.
18. K. Takahashi, H.-B. Cui, Y. Okano, H. Kobayashi, H. Mori, H. Tajima, Y. Einaga, O. Sato , Evidence of the Chemical Uniaxial Strain Effect on Electrical Conductivity in the Spin-Crossover Conducting Molecular System: [FeIII(qnal)2][Pd(dmit)2]5•Acetone, J. Am. Chem. Soc., 130, 6688–6689., 2008.05.
19. O. Sato, A.L. Cui, R. Matsuda, J. Tao, S. Hayami, Photoinduced Valence tautomerism in Co Compounds, Acc. Chem. Res., 40, 361-369, 2007.05.
20. Sato, O., Tao J., Zhang Y.Z., Control of Magnetic Properties through External Stimuli, Angew. Chem. Int. Ed., 46, 2152-2187, 2007.04.
21. Yue-Ling Bai, Jun Tao, Wolfgang Wernsdorfer, O. Sato, Rong-Bin Huang, and Lan-Sun Zheng, Coexistence of Magnetization Relaxation and Dielectric Relaxation in a Single-Chain Magnet, J. Am. Chem. Soc., 128, 16428-16429, 2006.12.
22. J. Tao, H. Maruyama, O. Sato, Valence tautomeric transitions with thermal hysteresis around room temperature and photoinduced effects observed in a cobalt-tetraoxolene complex., J. Am. Chem. Soc., 2006.02.
23. Z.-H. Ni, H.-Z. Kou, L.-F. Zhang, C. Ge, A.-L. Cui, R.-J. Wang, Y.-D. Li, O. Sato, [MnIII(salen)]6[FeIII(bpmb)(CN)2]6•7H2O: a Unique Cyanide-Bridged Nanosized Molecular Wheel, Angew. Chem. Int. Ed. Engl., 10.1002/anie.200502699, 44, 47, 7742-7745, 2005.12.
24. T. Yamamoto, Y. Umemura, O. Sato, Y. Einaga, Observation of the Anisotropic Photoinduced Magnetization Effect in Co-Fe Prussian Blue Thin Films Fabricated by Using the Clay Langmuir-Blodgett Films as a Template, J. Am. Chem. Soc., 10.1021/ja053131e, 127, 46, 16065-16073, 2005.11.
25. Mikami R., Taguchi M., Yamada K., Suzuki K., Sato O., Einaga Y., Reversible Photo-Switching of the Magnetization of Iron OxideNanoparticles at Room Tenperature, Angew.Chem.Int.Ed, 43, 6135-6139 (2004), 2004.05.
26. Meng, Q.-B. Takahashi, K., Zhang, X. -T., Stanto, I., Gu, Z. -Z., Fujishima, A., Sato, O., Fabrication of Efficient and Stable Solid State Dye-sensitized Solar Cell., Langmuir, 19, 3572-3574, 2003.01.
27. Gu, Z.-Z. Uetsuka, H., Takahashi, K., Nakajima, R., Onishi, H., Fujishima, A., Sato, O., Structural Color and the Lotus Effect, Angew. Chem. Int. Ed. Engl., 42, 894 (2003), 2003.01.
28. Sato, O. Hayami, S., Gu, Z. -Z., Takahashi, K., Nakajima, R. & Fujishima, A., Photo-Induced Reverse Valence Tautomerism in a Metastable Co Compound., Chem. Phys. Lett., 355, 169-174, 2002.01.
29. Shimamoto, N., Ohkoshi, S., Sato, O. & Hashimoto, K., Control of Charge-Transfer Induced Spin Transition Temperature on Cobalt-Iron Prussian Blue Analogues., Inorg. Chem., 41, 678-684, 2002.01.
30. Gu, Z.-Z., Fujishima, A. & Sato, O., Fabrication of High Quality Opal Films with Controllable Thickness., Chem. Mater., 14, 760-765, 2002.01.
31. Sato, O. Hayami, S., Gu, Z. -Z., Seki, K., Nakajima, R. & Fujishima, A., Photo-induced Long-Lived Intramolecular Electron Transfer in a Co Valence Tautomeric Complex., Chem. Lett., 874-875, 2001.01.
32. Sato, O., Einaga, Y., Fujishima, A., Hashimoto, K., Photo-induced Long-Range Magnetic Ordering of a Cobalt-Iron Cyanide, Inorg, Chem., 38, 4405 (1999), 1999.01.
33. Sato, O., Einaga, Y., Iyoda, T., Fujishima, A. & Hashimoto, K., Cation Driven Electron Transfer Involving a Spin Transition at Room Temperature in a Cobalt Iron Cyanide Thin Film., J. Phys. Chem., 101, 3903 (1997), 1997.01.
34. Sato, O., Iyoda, T., Fujishima, A., Hashimoto, K, Electrochemically Tunable Magnetic Phase Transition in a High-Tc Chromium Cyanide Thin Film., Science, 271, 49 (1996)..
35. Sato, O., Iyoda, T., Fujishima, A., Hashimoto, K., Photoinduced Magnetization of a Cobalt Iron Cyanicle., Science, 272, 704 (1996).
36. Yokoyama, T., Ohta, T., Sato, O. & Hashimoto, K., Characterization of Magnetic Materials of CoFe Cyanides by X-ray-absorption Fine-structure Spectroscopy., Phys. Rev. B, B58, 8257-8266 (1998).
37. Yokoyama, T. Kiguchi, M., Ohta, T., Sato, O., Einaga, Y. & Hashimoto, K., Local Structure of a Trapped Photo-Excited State of a FeCo Cyanide Studiedby X-ray-Absorption Fine Structure Spectroscopy., Phys. Rev. B, 60, 9340-9346 (1999).
38. Einaga, Y., Sato, O., Iyoda, T., Hashimoto, K. & Fujishima, A., Photo-functional Vesicles Containing Prussian Blue and Azobenzene., J. Am. Chem. Soc., 121, 3745-3750 (1999).
39. Hayami, S. Gu, Z. -Z., Shiro, M., Einaga, Y., Fujishima, A., Sato, O., First Observation of Light Induced Excited Spin State Trapping for an Iron(III) Complex., J. Am. Chem. Soc., 122, 7126 (2000).
40. Gu, Z.-Z., Fujishima, A. & Sato, O., Photochemically Tunable Colloidal Crystals., J. Am. Chem. Soc., 122, 12387-12388 (2000).
41. Gu, Z.-Z. Hayami, S., Kubo, S., Meng, Q. -B., Einaga, Y., Tryk, D. A., Fujishima, A. & Sato, O., Fabrication of Structured Porous Film by Electrophoresis., J. Am. Chem. Soc., 123, 175-176 (2001).
42. Hayami, S., Gu, Z.-Z., Yoshiki, H., Fujishima, A. & Sato, O., Iron(III) Spin-Crossover Compounds with a Wide Apparent Thermal Hysteresis around Room Temperature., J. Am. Chem. Soc., 123, 11644-11650 (2001)..
43. Gu, Z.-Z. Horie, R., Kubo, S., Yamada, Y., Fujishima, A. & Sato, O., Fabrication of a Metal-coated Three-dimensionally ordered Macroporous Film and its Application as a Refractive Index Sensor., Angew. Chem. Int. Ed. Engl., 41, 1153-1156 (2002)..
44. Gu, Z.-Z., Fujishima, A. & Sato, O., Patterning of a Colloidal Crystal Film on a Modified Hydrophilic and Hydrophobic Surface., Angew. Chem. Int. Ed. Emgl., 41, 2067-2070 (2002)..
45. Sato, O., Optically Switchable Molecular Solids: Photoinduced Spin-Crossover, Photochromism and Photoinduced Magnetization., Acc. Chem. Res., 36, 692 (2003).
46. Sato, O., Hayami, S., Einaga, Y. & Gu, Z.-Z., Control of the Magnetic and Optical Properties in Molecular Compounds by Electrochemical, Photochemical and Chemical Methods., Bull. Chem. Soc. Jpn, 76, 443-470 (2003).
47. Liu, H.-W. Matsuda, K. Gu, Z.-Z., Takahashi, K. Cui, A.-L. Nakajima, R. Fujishima A. & Sato, O., Reversible Valence Tautomerism Induced by a Single-Shot Laser Pulse in a Cobalt-Iron Prussian Blue Analogue., Phys. Rev. Lett., 90, 167403 (2003).
1. 佐藤 治, Dynamic Molecular Crystals with Swichable Physical Properities, 1st Japan-Australia Joint Symposium, 2016.09.
2. Osamu Sato, Cyanide-Bridged Fe42 High-Spin Nanocage with S=90/2, The 9th Japanese-Russian Workshop on Open Shell Compounds and Molecular Spin Devices, 2015.11.
Membership in Academic Society
  • Japan Society of Coordination Chemistry
Educational Activities
Chemical Bonding, Inorganic Chemistry, Instrumental Analysis and Design of Molecular functions.
Professional and Outreach Activities
We are collaborating with the scientists in The University of Manchester, Tsinghua, Southeast and Xiamen University..