Takao Lab, Laboratory for Zero-Carbon Energy,
Institute of Innovative Research, TokyoTech.

Tel & FAX: +81 3 5734 2968
E-mail: takao.k.ac[atmark]m.titech.ac.jp

Laboratory for Zero-Carbon Energy,
Institute of Innovative Research, Tokyo Institute of Technology

Takao Laboratory

To guarantee feasibility and sustainability of nuclear power system, it is important to understand fundamental chemistry of actinides and fission products, which are highly relevant to nuclear fuel cycle and related engineering. Main focus of this lab is coordination and solution chemistry of these metal ions as well as organic and computational chemistry, green chemistry with ionic liquids, and microwave technology to develop bases of fuel reprocessing and treatment of radioactive wastes, peaceful and effective use of depleted/recovered uranium, and decontamination process for retrieval from the Fukushima accident.

Keywords: Nuclear Fuel Cycle, Actinide Chemistry, Ionic Liquid, Treatment and Disposal of Radioactive Wastes, Decontamination, Complex Catalyst, Separation of Nuclides, Reactor Hydrochemistry

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- Apr 02, 2024 Paper Accepted
Tsushima, S.; Kretzschmar, J.; Doi, H.; Okuwaki, K.; Kaneko, M.; Mochizuki, Y.; Takao, K. "Towards tailoring hydrophobic interaction with uranyl(VI) oxygen for C-H activation", Chem. Commun. 2024, 60, 4769-4772. DOI:10.1039/D4CC01030B
Graphical abstract: Towards tailoring hydrophobic interaction with uranyl(vi) oxygen for C–H activation
- Feb 22, 2024 Paper Accepted
Takao. K.; Ouchi, K.; Komatsu, A.; Kitatsuji, Y.; Watanabe, M. "Securing Reversibility of UVO2+/UVIO22+ Redox Equilibrium in [emim]Tf2N-Based Liquid Electrolytes towards Uranium Redox-Flow Battery" Eur. J. Inorg. Chem. 2024, 27, e202300787.  DOI:10.1002/ejic.202300787.
- Aug 31, 2023 Paper Accepted
Takeyama, T.; Tsushima, S.; Gericke, R.; Kaden, P.; Mӓrz, J.; Takao, K. "Fate of Oxidation States at Actinide Centers in Redox-Active Ligand Systems Governed by Energy Levels of 5f Orbitals", Chem. Eur. J. 2023, e202302702. DOI:10.1002/chem.202302702
Description unavailable
- Aug 17, 2023 Paper Published
Yamamoto, M.; Takamura, Y.; Kokubo, Y.; Urushihara, M.; Horiuchi, N.; Dai, W.; Hayasaka, Y.; Kita, E.; Takao, K. "Solid-State Schikorr Reaction from Ferrous Chloride to Magnetite with Hydrogen Evolution as the Kinetic Bottleneck" Inorg. Chem. in press. DOI:10.1021/acs.inorgchem.3c01676.
- Apr 26, 2023 Paper Published
Takao, K. "How does chemistry contribute to circular economy in nuclear energy systems to make them more sustainable and ecological?" Dalton Trans. 2023, 52, 9866-9881. doi:10.1039/D3DT01019H [Perspective][HOT Article Collection][Vol. 52, Issue 29, Front Cover]
Graphical abstract: How does chemistry contribute to circular economy in nuclear energy systems to make them more sustainable and ecological?
- Mar 8, 2023 Paper Accepted.
Takeyama, T.; Tsushima, S.; Takao, K. "Utility of redox-active ligands for reversible multi-electron transfer in uranyl(VI) complexes" Inorg. Chem. Frontiers, 2023, 10, 4028-4044. doi: 10.1039/D3QI00189J  [Vol. 10, Issue 14, Front Cover]
Graphical abstract: Utility of redox-active ligands for reversible multi-electron transfer in uranyl(vi) complexes
- Feb 27, 2023 Paper Accepted.
Takeyama, T.; März, J.; Ono, R.; Tsushima, S.; Takao. K. "Neptunyl(VI) Nitrate Coordination Polymer with Bis(2-pyrrolidone) Linkers to Highlight Crystallographic Analogy and Solubility Difference in Actinyl(VI) Nitrates" Inorganics, 2023, 11, 104. doi: 10.3390/inorganics11030104 [Open Access]

- Dec 15, 2022 Paper Accepted.
Ono, R.; Kazama, H.; März, J.; Tsushima, S.; Takao, K. "Crystal Structures of Ce(IV) Nitrates with Bis(2-pyrrolidone) Linker Molecules Desposited from Aqueous Solutions with Different HNO3 Concentrations" Inorg. Chem. 2023, 62, 454-463. doi: 10.1021/acs.inorgchem.2c03554
- Oct 3, 2022 Paper Accepted.
Yamato, N.; Kumagai, N.; Okahira, M.; Kosaka, S.; Kodama, S.; Yamamoto, R.; Yamamoto, A.; Takao, K.; Yamamoto M. "Non-aqueous bonding of leuprorelin to Ochratoxin A for peptide-based solid-phase extraction" Chem. Commn. 2022, 58, 12106-12109. doi:10.1039/D2CC04430G
- Aug 22, 2022 Paper Accepted.
Takeyama, T.; Takao, K. "Effects of coordinating heteroatoms on molecular structure, thermodynamic stability and redox behavior of uranyl(VI) complexes with pentadentate Schiff-base ligands" RSC Adv. 2022, 12, 24260-24268. doi:10.1039/D3RA04639C [Open Access]

- Apr 6, 2022 Paper Accepted.
Takeyama, T.; Iwatsuki, S.; Tsushima S.; Takao, K. "Synthesis and characterization of uranyl(VI) complex with 2,6-pyridine-bis(methylaminophenolato) and its ligand-centred aerobic oxidation mechanism to diimino derivative" Dalton Trans. 2022, 51, 6576-6586.. doi:10.1039/D2DT00325B [Outside Back Cover]
- Mar 29, 2022 Paper Accepted.
 Mizumachi, T.; Sato, M.; Kaneko, M.; Takeyama, T.; Tsushima, S.; Takao, K. "Fully Chelating N3O2-Pentadentate Planar Ligands Designed for Strongest and Selective Capture of Uranium from Seawater" Inorg. Chem. 2022, 61, 6175-6181. doi:10.1021/acs.inorgchem.2c00306
- Mar 14, 2022 Paper Accepted.
Takao, K.; Tsubomura T. "Design and Demonstration of Absorption/Luminescence-Compatible Spectroelectrochemical Cell with Optically Transparent Thin-Layer Electrode" J. Electroanal. Chem. 2022, 911, 116217. doi:0.1016/j.jelechem.2022.116217
- Jan 19, 2022 Paper Accepted.
Tsushima, S.; Takao, K. "Hydrophobic Core Formation and Secondary Structure Elements in Uranyl(VI)-Binding Peptides" Phys. Chem. Chem. Phys. 2022, 24, 4455-4461, [Open Access] doi:10.1039/D1CP05401E
- Sep 13, 2021 Paper Accepted.
Matsuoka, M.; Tsushima, S.; Takao, K. "Fluorite-like Hydrolyzed Hexanuclear Coordination Clusters of Zr(IV) and Hf(IV) with syn-syn Bridging N,N,N-Trimethylglycine in Soft Crystal Structures Exhibiting Cold-Crystallization" Inorg. Chim. Acta, 2021, 528, 120622, doi:10.1016/j.ica.2021.120622.
- Aug 5, 2021 Paper Accepted.
Zheng, Z.; Arai, T.; Takao, K. "Complexation-Distribution Separated Solvent Extraction Process Designed for Rapid and Efficient Recovery of Inert Platinum Group Metals" ACS Omega, 2021, 6, 21809-21818. doi: 10.1021/acsomega.1c03565.
- Jul 16, 2021 Paper Accepted.
Takeyama, T.; Tsushima, S.; Takao, K. "Effects of Substituents on the Molecular Structure and Redox Behavior of Uranyl(V/VI) Complexes with N3O2-Donating Schiff Base Ligands" Inorg. Chem. 2021, 60, 11435-11449. doi:10.1021/acs.inorgchem.1c01449
- Nov 26, 2020 Paper Accepted.
Takeyama, T.; Inoue, Y.; Chayama, K.; Iwatsuki, S. Takao, K. "Structural Chemistry and Stimuli-Responsive Phase Transition of N,N'-Dialkylimidazoium Nonafluorobutanesulfonate Ionic Liquids" Cryst. Growth Des. in press. doi: 10.1021/acs.cgd.0c01419.
- July 22, 2020
Paper Accepted.
 Takao, K.; Ikeda, Y. "Coordination chemistry of actinide nitrates with cyclic amide derivatives for development of nuclear fuel materials selective precipitation (NUMAP) reprocessing method"
Eur. J. Inorg. Chem. 2020, 3443-3459, Minireview. doi:10.1002/ejic.202000504
- July 14, 2020 Paper Accepted.
Kazama, H.; Takao, K. "Molecular Design of Double-Headed 2-Pyrrolidone Derivatives for Separation/Co-precipitation of UO22+ from/with Tetravalent Actinides towards Nuclear Fuel Recycling" Chem. Lett. 2020, 49, 1201-1205, doi:10.1246/cl.200457. [Open Access]
- May 22, 2020 Paper Accepted.
Takao, K.; Takao, S.; Ikeda, Y. "Facile and Selective Palladium Recovery from Acid Leachate of Nuclear Waste Glass with Hydrazine Reduction Assisted by Coexisting Chalcogens" Chem. Lett. 2020, 49, 995-998. doi:10.1246/cl.200314
- April 25, 2020 Paper Accepted.
Inoue, T.; Kazama, H.; Tsushima, S.; Takao, K. "Essential Role of Heterocyclic Structure of N-Alkylated 2-Pyrrolidone Derivatives for Recycling Uranium from Spent Nuclear Fuels" Bull. Chem. Soc. Jpn. 2020, 93, 846-853. doi:10.1246/bcsj.20200061
- Feb 3, 2020 Paper Accepted. (Collaboration with Dr. Juliane März (HZDR))
Takao, K.; März, J.; Matsuoka, M.; Mashita, T.; Kazama, H.; Tsushima, S. "Crystallization of colourless hexanitratoneptunate(IV) with anhydrous H+ countercations trapped into hydrogen bond polymer with diamide linkers" RSC Adv. 2020, 10, 6082-6087 (Open Access). doi:10.1039/C9RA10090C

- Nov 8, 2019 Paper Accepted. (Collaboration with Mr. Soma Kono (currently in JAEA), Prof. Tsuyoshi Arai in Shibaura Institute of Technology))
Kono, S.; Takao, K.; Arai, T. "Direct and Selective Electrodeposition of Palladium from Betainium Bis(trifluoromethylsulfonyl)amide Ionic Liquid Phase after Solvent Extraction together with Other Platinum Group Metals" 日本原子力学会和文論文誌 (only in Japanese).
- Oct 17, 2019 Paper Accepted.
Kazama, H.; Tsushima, S.; Takao, K. "Crystallization of Anhydrous Proton from Acidic Aqueous Solution with Diamide Building Block" Cryst. Growth Des. doi:10.1021/acs.cgd.9b01214

- May 12, 2019 Paper Accepted.
 Zheng, Z.; Arai, T.; Takao, K. "Kinetic and Thermodynamic Requirements to Extend Solvent Compatibility in Thermal-Assisted Extraction of Inert Platinum Group Metals" ACS Sustainable Chem. Eng. in press. doi:10.1021/acssuschemeng.9b01622
- Apr 11, 2019 Paper Accepted.
Mashita, T.; Tsushima, S.; Takao, K. "Photocatalytic Oxygenation of Cyclohexene Initiated by Excitation of [UO2(OPCyPh2)4]2+ under Visible Light" ACS Omega, in press. doi:10.1021/acsomega.9b00635

- Nov 15, 2018 Paper Accepted.
Takao, K.; Kazama, H.; Ikeda, Y.; Tsushima, S. "Crystal Structure of Regularly Th-Symmetric [U(NO3)6]2- Salts with Hydrogen BOnd Polymers of Diamide Building Blocks" Angew. Chem. Int. Ed. in press. doi:10.1002/anie.201811731  doi:10.1002/ange.201811731

- Sep 28, 2018 New Member Joined ! Welcome to Takao Lab.
- Sep 18, 2018 Paper Accepted.
Takao, K.; Mori, T.; Kubo, M.; Uehara, A.; Ikeda, Y. "Wet chemical processing for nuclear waste glass to retrieve radionuclides" J. Hazard. Mater. 2019, 362, 368-374. doi:10.1016/j.jhazmat.2018.09.042
This work was funded by ImPACT Program of Council for Science, Technology, and Innovation (Cabinet Office, Government of Japan).
- Aug 22, 2018 Paper Accepted (1st Authored by Takanori, Mashita (M2), Collaboration with Prof. Dr. Satoru Tsushima, HZDR/TokyoTech WRHI)
Mashita, T.; Tsushima, S.; Takao, K. "Controlling lability of uranyl(VI) through intramolecular π-π stacking" Dalton Trans. in press. doi:10.1039/C8DT02600A
- Aug 6, 2018 43rd International Conference on Coordination Chemistry (ICCC2018, Sendai, Japan)
- Matsuoka, M. (Poster) "Synthesis and Characterization of Hydrolyzed Hexanuclear Clusters of Tetravalent Metal Ions with Amino Acid Derivatives"
- Mashita, T. (Poster) "Unexpectedly Slow Ligand Exchange Reaction of Homoleptic Uranyl Complex with Phosphine Oxide: Uranyl Lability Controlled by Interligand π-π Stacking"
- Takao, K. (Invited Talk) "X-ray Absorption Spectroscopic Titration to Explore Structure and Speciation in Solution Coordination Chemistry"
- Apr 9, 2018 New Members Joined! Welcome to Takao Lab.
- Mar 6, 2018 Paper Accepted (Collaboration with Prof. Dr. Satoru Tsushima, HZDR/TokyoTech WRHI)
Takao, K.; Tsushima, S. "Borohydrides oxidation by photoexcited [UO2(CO3)3]4-" Dalton Trans. in press. doi:10.1039/c8dt00559a

Paper Accepted (Collaboration with Dr. Kotaro Nakata, CRIEPI, and co-workers)
Nakata, K.; Hironaga, M.; Minato, D.; Kino, K.; SAkashita, A.; Takao, K.; Sakakihara, T. "Investigation of C-14 in the CRUD collected on the coolant filter for safety disposal of radioactive waste containing C-14 (II) - Chemical alteration of ion exchange resin under simulated condition in primary coolant of PWR -" MRS Adv. in press.doi:10.1557/adv.2018.271
- Jan 18, 2018 Paper Accepted (Collaboration with Mr. Soma Kono, Prof. Tsuyoshi Arai in Shibaura Institute of Technology)
Kono, S.; Kazama, H.; Mori, T.; Arai, T.; Takao, K. "Significant Acceleration of PGMs Extraction with UCST-type Thermomorphic Ionic Liquid at Elevated Temperature" ACS Sustainable Chem. Eng. doi:10.1021/acssuschemeng.7b04447
- Oct 13, 2017 Paper Accepted (Collaboration with Prof. Satoru Tsushima in HZDR, Germany)
Kazama, H.; Tsushima, S.; Ikeda, Y.; Takao, K. "Molecular and Crystal Structures of Uranyl Nitrate Coordination Polymers with Double-Headed 2-Pyrrolidone Derivatives" Inorg. Chem.  doi:10.1021/acs.inorgchem.7b02250
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- July 3, 2017 [Member] Page Updated.
- May 27, 2017 Paper Accepted (Collaboration with Prof. Masahiko Matsumiya and Dr. Yuji Sasaki)
Murakami, S.; Matsumiya, M.; Sasaki, Y.; Suzuki, S.; Hisamatsu, S.; Takao, K. "Investigation into Coordination States of Diglycolamide and Dioxaoctanediamide Complexes with Lanthanide Elements Using Spectroscopic Methods" Solv. Extr. Ion Exc.
- Feb. 20, 2017 Paper Accepted. (Collaboration with Prof. Emer. Hiroshi Tomiyasu, Qualtec)
Tomiyasu, H.; Shikata, H.; Takao, K.; Asanuma, N.; Taruta, S.; Park, Y.-Y. "An Aqueous Electrolyte of the Widest Potential Window and Its Superior Capability for Capacitors" Sci. Rep. doi:10.1038/srep45048
- Feb. 8, 2017 Paper Accepted.
Takao, K.; Akashi, S. "Exploring Catalytic Activity of Lewis-acidic Uranyl Complexes in Nucleophilic Acyl Substitution of Acid Anhydrides" RSC Adv. 2017, 7, 12201-12207. doi:10.1039/C6RA27796A
Graphical abstract: Exploring the catalytic activity of Lewis-acidic uranyl complexes in the nucleophilic acyl substitution of acid anhydrides
- Aug. 22, 2016 Paper Accepted.
Mori, T.; Ikeda, Y.; Takao, K. "Extraction Behavior of U(VI) Using Novel Betainium-Type Ionic Liquids: More Hydrophobic Cations Enhances Extractability, Selectivity, and Recyclability" Bull. Chem. Soc. Jpn. in press. doi:10.1246/bcsj.20160210
- March 24, 2016

Paper Accepted.
Ikeda, S.; Mori, T.; Ikeda, Y.; Takao, K. "Microwave-Assisted Solvent Extraction of Inert Platinum Group Metals from HNO3(aq) to Betainium-Based Thermomorphic Ionic Liquid" ACS Sustainable Chem. Eng. doi: 10.1021/acssuschemeng.6b00186
- February 17, 2016 [Equipments] Page Updated.
- December 3, 2015

Paper Accepted.
Mori, T.; Takao, K.; Ikeda, Y. "Syntheses and Physical Properties of Novel Betainium-type Ionic Liquids Derived from Amino Acids" Chem. Lett. doi: 10.1246/cl.151044
- September 8, 2015

Paper Accepted.
Takao, K.; Arakawa, K.; Mori, T.; Harada, M.; Ikeda, Y. “Outer-Sphere Extraction of Uranyl(VI) from HNO3(aq) to 1-Butyl-3-methylimidazolium Nonafluorobutanesulfonate Ionic Liquid −Towards Decontamination of Uranium Wastes−” Bull. Chem. Soc. Jpn. doi: 10.1246/bcsj.20150268
- April 1, 2015
Takao Lab is launched !
- September 16, 2014

Selected Paper in Bulletin of Chemical Society of Japan