Hasobe, Taku



Faculty of Science and Technology, Department of Chemistry (Yagami)



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Books 【 Display / hide

  • Handbook of Porphrin Science

    HASOBE Taku, World Scientific Publishing Co. Pte. Ltd., 2014

    Scope: Supramolecular Assemblies of Porphyrins and Phthalocyanines Derivatives for Solar Energy conversion and Molecular Electronics

  • 高次π空間の創発と機能開発

    HASOBE Taku, CMC出版, 2013.03

    Scope: 158-165

  • Handbook for Carbon Nanomaterials

    HASOBE Taku, 2012.06

    Scope: 95-130

  • Energy and Electron Transfer Processes in Multiporphyrin Arrays

    HASOBE Taku, 2012.03

    Scope: 499-536

  • 光化学 Vol. 41, No. 3, 157-159 (2010)

    羽曾部 卓・酒井 隼人, 光科学協会, 2010.12

    Scope: 157-159

Papers 【 Display / hide

  • A Pentacene-based Nanotube Displaying Enriched Electrochemical and Photochemical Activities

    Kuroda K., Yazaki K., Tanaka Y., Akita M., Sakai H., Hasobe T., Tkachenko N., Yoshizawa M.

    Angewandte Chemie - International Edition (Angewandte Chemie - International Edition)  58 ( 4 ) 1115 - 1119 2019.01

    ISSN  14337851

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    © 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Unlike previously well-studied, acyclic pentacene oligomers, the first synthesis of a cyclic pentacene trimer with a fixed tubular conformation is reported. A short-step synthesis starting from common pentacenequinone yielded the target molecule with a 1.5 nanometer length and a subnanometer pore. Steady-state spectroscopic analyses revealed that the close proximity of the non-conjugated, three pentacene chromophores allows the nanotube to display stepwise electrochemical/chemical oxidation characteristics. Furthermore, time-resolved transient absorption measurements elucidated the generation of an excited triplet state of the nanotube, with high quantum yield reaching about 180 % through intramolecular singlet fission and a very long triplet lifetime.

  • Quantitative Sequential Photoenergy Conversion Process from Singlet Fission to Intermolecular Two-Electron Transfers Utilizing Tetracene Dimer

    Nakamura S., Sakai H., Nagashima H., Kobori Y., Tkachenko N., Hasobe T.

    ACS Energy Letters (ACS Energy Letters)  4 ( 1 ) 26 - 31 2019.01

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    © 2018 American Chemical Society. Singlet fission (SF) theoretically enables the performance of the sequential photoenergy conversion process starting from the singlet state and leading to electron transfer (ET) with the radical ion pair quantum yield approaching 200%. Additionally, the long lifetime of the triplet state opens the possibility for an intermolecular ET process in a diffusion-limited reaction. However, the quantitative two-electron transfer process through SF has yet to be reported. Herein we demonstrate the quantitative sequential process involving SF and leading to intermolecular two-electron transfers using 2,2′-biphenyl-bridged tetracene dimer (Tet-BP-Tet: SF and electron donor) and chloranil (Ch: electron acceptor). The high-yield and long-lived individual triplet excited states of Tet-BP-Tet by SF (φ T = 175 ± 5% and τ T = 0.29 ms) resulted in the quantitative two-electron transfer process (φ ET = 173 ± 5%) with Ch in benzonitrile.

  • High-Yield Generation of Triplet Excited States by an Efficient Sequential Photoinduced Process from Energy Transfer to Singlet Fission in Pentacene-Modified CdSe/ZnS Quantum Dots

    Sakai H., Inaya R., Tkachenko N., Hasobe T.

    Chemistry - A European Journal (Chemistry - A European Journal)  24 ( 64 ) 17062 - 17071 2018.11

    ISSN  09476539

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    © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim Singlet fission (SF) is expected to improve photoenergy conversion systems by generating two electrons from one photon. Pentacenes meet the energy-level matching condition between a singlet and two triplet states: [E(S1)≥2E(T1)]. However, the molar absorption coefficients of pentacenes in the approximately 400–500 nm region are limited, whereas quantum dots, such as CdSe/ZnS (QD), possess high fluorescence quantum yields and particle-size-dependent fluorescence wavelengths. Thus, a combination of QD (D) and pentacene (A) provides a system of both an enhanced light-harvesting efficiency throughout the solar spectrum and an efficient conversion of the harvested light into the triplet states by SF. Based on these points, m-phenylene-bridged triisopropylsilane (TIPS)-pentacene dimer-functionalized QD (denoted as m-(Pc)2-QD) was synthesized to examine the sequential photoinduced process from energy transfer to SF. In femtosecond transient absorption measurements, initial energy transfer from QD to pentacene (quantum yield: 87 %) and subsequent SF were efficiently observed. The quantum yield of triplet states of pentacene units (ΦΤ) based on the excitation of QD attained is 160±6.7 %.

  • Significant Enhancement of Absorption and Luminescence Dissymmetry Factors in the Far-Red Region: A Zinc(II) Homoleptic Helicate Formed by a Pair of Achiral Dipyrromethene Ligands

    Ito H., Sakai H., Okayasu Y., Yuasa J., Mori T., Hasobe T.

    Chemistry - A European Journal (Chemistry - A European Journal)  24 ( 63 ) 16889 - 16894 2018.11

    ISSN  09476539

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    © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim A homoleptic zinc(II) helicate organized by a pair of achiral dipyrromethene ligands through zinc(II) coordination was synthesized to evaluate the chiroptical properties. This zinc complex showed strong exciton-coupled chiroptical responses from the helical configuration with a large absorption dissymmetry factor |gabs| (up to 0.20). More importantly, intense polarized luminescence in the far-red region (700–850 nm) with a fluorescence quantum yield ΦFL of 0.23 was observed for this helicate with a dissymmetry factor |glum| of 0.022, the largest value among rare-earth- and precious-metal-free small molecules. These unprecedentedly large g values were supported by theoretical calculations.

  • Inter- and Intramolecular Electron-Transfer Reduction Properties of Coronenediimide Derivatives via Photoinduced Processes

    Yoshida M., Sakai H., Ohkubo K., Fukuzumi S., Hasobe T.

    Journal of Physical Chemistry C (Journal of Physical Chemistry C)  122 ( 25 ) 13333 - 13346 2018.06

    ISSN  19327447

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    Copyright © 2017 American Chemical Society. Coronenediimide derivatives with five- or six-membered maleimide groups [denoted as Cor(5Im)2 and Cor(6Im)2] were employed as electron acceptors to examine the electron-transfer reduction properties through photochemical and electrochemical measurements. In steady-state absorption and fluorescence measurements, the spectra of Cor(5Im)2 and Cor(6Im)2 became remarkably broadened and red-shifted as compared to pristine coronene (Cor). These results are supported by electrochemical measurements and DFT calculations. The rate constants of photoinduced intermolecular electron transfer from various donor molecules to 3Cor(5Im)2∗ or 3Cor(6Im)2∗ are determined by nanosecond transient absorption measurements. Although the back-electron-transfer reactions examined in this study proceed with the diffusion-limited rate constant in benzonitrile (PhCN), the rate constants of forward electron-transfer reactions (ket) increase with an increase in the driving force of electron transfer (-ΔGet) to approach the diffusion-limited rate constant. When the driving force dependence of ket was fit on the basis of the Marcus theory of electron transfer, the reorganization energy (λ) of the electron-transfer reduction of Cor(5Im)2 and Cor(6Im)2 are determined to be 0.77 and 1.15 eV, respectively. A new covalently perylene-linked donor-acceptor dyad was also synthesized to investigate the dynamics of ultrafast photoinduced intramolecular electron transfer.

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Papers, etc., Registered in KOARA 【 Display / hide

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Presentations 【 Display / hide

  • Control of Excite-State Dynamics and Optical Applications of Functional Supramolecular Architectures

    HASOBE Taku

    University Research Semina (University of Potsdam) , 


    Oral presentation (invited, special)

  • Control of Excite-State Dynamics of Functional Supramolecular Architectures for Optical Applications

    HASOBE Taku

    TUT University Seminar (Tampere University of Technology) , 


    Oral presentation (invited, special)

  • 有機低分子材料のナノ・メゾスケール構造体における励起状態ダイナミクス制御と応用

    HASOBE Taku

    高分子学会 印刷・情報記録・表示研究会および光反応・電子用材料研究会 (東京理科大学 森戸記念館 第1フォーラム) , 


    Oral presentation (invited, special)

  • π共役分子および集積体の励起状態制御と機能性有機-無機複合材料への展開

    HASOBE Taku



    Oral presentation (invited, special)

  • π共役系分子集積体の励起状態ダイナミクス制御と機能発現

    HASOBE Taku




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Research Projects of Competitive Funds, etc. 【 Display / hide

  • Photofunctional Science of Meso-Hierarchy


    学術変革領域研究(A), Principal investigator

  • 水圏機能材料の励起ダイナミクス制御


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 新学術領域研究(研究領域提案型), Principal investigator

  • 一重項分裂における動的エキシトン解析


    MEXT,JSPS, Grant-in-Aid for Scientific Research, 学術変革領域研究(A), Principal investigator

  • 表面プラズモン効果との融合による一重項分裂のパラダイムシフト


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Challenging Research (Exploratory), Principal investigator

  • 多重分子協調による多励起子生成反応の新展開


    MEXT,JSPS, Grant-in-Aid for Scientific Research, Grant-in-Aid for Scientific Research (B), Principal investigator

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Intellectual Property Rights, etc. 【 Display / hide

  • 内包フラーレンを用いた光電変換装置

    Date applied: P2013-200603  2013.09 

    Date announced: P2015-69731A  2015.04 

    Patent, Joint

Awards 【 Display / hide

  • JPP/SPP Young Invetigator Awards

    Taku Hasobe, 2014.06, Society of Porphyrins and Phthalocyanines

    Type of Award: International academic award (Japan or overseas)

  • SPP/JPP Young Investigator Awards

    2014.06, Society of Porphyrins and Phthalocyanines

  • The Young Scientists’ Prize, The Commendation for Science and Technology by the Minister of Education, Culture, Sports, Science and Technology

    HASOBE Taku, 2010.04, 文部科学省, 光電変換機能を有する分子集合体の創製と応用についての研究

    Type of Award: Other

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Courses Taught 【 Display / hide











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Committee Experiences 【 Display / hide

  • 2015.04

    関東支部常任幹事, 日本化学会

  • 2015.04

    日本化学会代議員, 日本化学会