ソフトキラル分子結晶による刺激応答性室温円偏光蓄光材料の創生

• Project Area: Soft Crystals: Science and Photofunctions of Easy-Responsive Systems with Felxibility and Higher-Ordering
• Project/Area Number: 18H04507
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Research Institution: The University of Electro-Communications
• Principal Investigator: 平田 修造 電気通信大学, 大学院情報理工学研究科, 助教 (20552227)
• Project Period (FY): 2018-04-01 – 2020-03-31
• Project Status: Completed (Fiscal Year 2019)
• Budget Amount: ¥4,940,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥1,140,000); Fiscal Year 2019: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000); Fiscal Year 2018: ¥2,470,000 (Direct Cost: ¥1,900,000、Indirect Cost: ¥570,000)
• Keywords: 室温りん光 / 蓄光 / 三重項励起子 / 励起子拡散 / 高解像度顕微鏡 / 相変化 / ソフトクリスタル / 分子結晶 / 凝集誘起発光 / 三重項励起状態 / 高解像顕微鏡 / 量子化学計算 / 円偏光発光 / 相転移

Outline of Annual Research Achievements

1秒以上の長い寿命を有する室温りん光（蓄光）は2015年からいくつかの芳香族結晶からも報告されてきているが、分子結晶から室温蓄光を得るためには結晶内の強い分子間相互作用を用いることによる剛直性の追求が一般的であった。最近申請者は、芳香族部位に敢えてより柔軟なシクロ環であるH8部位を導入したH8-binaphytyl骨格のキラル芳香族分子の結晶を用いると効率よい室温蓄光が得られることを見出した。キラル分子結晶からの蓄光特性の発現は初めての現象であり、円偏光蓄光特性などの新規機能発現が期待される。さらに、柔軟なシクロ環であるH8部位の導入により、このような結晶群では蓄光特性が低刺激の力学応答や低温で変化する可能性がある。本研究では、ソフトな非共役部位を有する新規キラル芳香族分子の結晶群を用いて、円偏光蓄光機能の構築と、外部刺激による円偏光蓄光の動的制御を目的とする。
三重項励起子拡散が大きいことが数多くの重原子フリーの分子結晶から長い寿命の室温りん光が生じない理由であることを高解像顕微鏡と計算科学を協働させることで明確にした。さらに高効率室温りん光を示す重原子フリードーパントを、同等の最低励起三重項(T1)エネルギーを示すフルオレン結晶とH8-BINAP結晶にそれぞれドープしたところ、フルオレン結晶中では室温りん光を示さなかったが、H8-BINAP結晶中ではドーパント由来の強い長寿命の室温りん光が観測された。この原因がフルオレン結晶が三重項励起子拡散能が大きい一方で、H8-BINAP結晶中では三重項励起子拡散が生じにくいことに由来することを計算科学的アプローチにより確認した。
計算科学により三重項励起子拡散能が可逆的に変化する結晶を探索し、異なる蒸気下で結晶構造が変化することで三重項状態の電子構造と励起子拡散能が変化し、微弱に長寿命の室温りん光応答が可逆的に変化する結晶を見出した。

Research Progress Status

令和元年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

令和元年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Highly efficient persistent room-temperature phosphorescence from heavy atom-free molecules triggered by hidden long phosphorescent antenna (2020)
  • Author(s): Indranil, Bhattacharjee, Shuzo Hirata*
  • Journal Title: Advanced Materials Volume: 32 Issue: 31 Pages: 2001348-2001348
  • DOI: 10.1002/adma.202001348
  • Peer Reviewed / Open Access
• [Journal Article] Energy localization vs. charge funneling in aggregates of CsPbBr3 perovskite nanocrystals (2020)
  • Author(s): Dharmendar Kumar Sharma*, Shuzo Hirata, Martin Vacha*
  • Journal Title: Journal of Luminescence Volume: 222 Pages: 117119-117119
  • DOI: 10.1016/j.jlumin.2020.117119
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Effect of Tris(trimethylsilyl)silyl Group on the Fluorescence and Triplet Yields of Oligothiophenes (2020)
  • Author(s): Hirata, S.;* Nishio, M.; Uchida, H.; Usuki, T.; Nakae, T.; Miyachi, M.; Yamanoi, Y.;* Nishihara, H.*
  • Journal Title: J. Phys. Chem. C Volume: 124 Issue: 5 Pages: 3277-3286
  • DOI: 10.1021/acs.jpcc.9b10718
  • Peer Reviewed
• [Journal Article] Single-particle electroluminescence of CsPbBr3 perovskite nanocrystals reveals particle-selective recombination and blinking as key efficiency factors (2019)
  • Author(s): Dharmendar Kumar Sharma*, Shuzo Hirata, Martin Vacha*
  • Journal Title: Nature Communications Volume: 10 Issue: 1 Pages: 4499-4499
  • DOI: 10.1038/s41467-019-12512-y
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Roles of Localized Electronic Structures caused by π Degeneracy due to Highly Symmetric Heavy Atom-Free Conjugated Molecular Crystals Leading to Efficient Persistent Room-Temperature Phosphorescence (2019)
  • Author(s): Shuzo Hirata
  • Journal Title: Advanced Science Volume: 6 Pages: 1900410-1900410
  • Peer Reviewed / Open Access
• [Journal Article] Suppressed Triplet Exciton Diffusion Due to Small Orbital Overlap as a Key Design Factor for Ultralong‐Lived Room‐Temperature Phosphorescence in Molecular Crystals (2019)
  • Author(s): Kaishi Narushima, Yasuhiro Kiyota, Takehiko Mori, Shuzo Hirata, Martin Vacha
  • Journal Title: Advanced Materials Volume: 31 Issue: 10 Pages: 1807268-1807268
  • DOI: 10.1002/adma.201807268
  • Peer Reviewed
• [Journal Article] Stark Effect and Environment Induced Modulation of Emission in Single Halide Perovskite Nanocrystals (2019)
  • Author(s): Dharmendar Kumar Sharma, Shuzo Hirata, Vasudevanpillai Biju, Martin Vacha
  • Journal Title: ACS nano Volume: 13 Issue: 1 Pages: 624-632
  • DOI: 10.1021/acsnano.8b07677
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A Colorless Semi-aromatic Polyimide Derived from a Sterically Hindered Bromine-Substituted Dianhydride Exhibiting Dual Fluorescent and Phosphorescent Emission (2019)
  • Author(s): Kenta Kanosue, Shuzo Hirata, Martin Vacha, Ramunas Augulis, Vidmantas Gulbinas, Ryohei Ishige, Shinji Ando
  • Journal Title: Materials Chemistry Frontier Volume: 3 Issue: 1 Pages: 39-49
  • DOI: 10.1039/c8qm00409a
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Wavelength-Tunable Band-Edge Photoluminescence of Nonstoichiometric Ag-In-S Nanoparticles via Ga3+ Doping (2018)
  • Author(s): Tatsuya Kameyama, Marino Kishi, Chie Miyamae, Dharmendar Kumar Sharma, Shuzo Hirata, Takahisa Yamamoto, Taro Uematsu, Martin Vacha, Susumu Kuwabata, and Tsukasa Torimoto
  • Journal Title: ACS Applied Mater. Interfaces Volume: 10 Issue: 49 Pages: 42844-42855
  • DOI: 10.1021/acsami.8b15222
  • Peer Reviewed / Open Access
• [Journal Article] Identification of Short- and Long-Wavelength Emitting Chlorophylls in Cyanobacterial Photosystem I by Plasmon-Enhanced Single-Particle Spectroscopy at Room Temperature (2018)
  • Author(s): Soya Hatazaki, Dharmendar Kumar Sharma, Shuzo Hirata, Keiji Nose, Tomokazu Iyoda, Adrian Kolsch, Heiko Lokstein, Martin Vacha
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 9 Pages: 6669-6675
  • Peer Reviewed
• [Journal Article] Narrow band-edge photoluminescence from AgInS2 semiconductor nanoparticles by the formation of amorphous III-VI semiconductor shells (2018)
  • Author(s): Taro Uematsu, Kazutaka Wajima, Dharmendar Kumar Sharma, Shuzo Hirata, Takahisa Yamamoto, Tatsuya Kameyama, Martin Vacha, Tsukasa Torimoto, and Susumu Kuwabata
  • Journal Title: NPG Asia Mater. Volume: 10 Issue: 8 Pages: 713-726
  • DOI: 10.1038/s41427-018-0067-9
  • Peer Reviewed / Open Access
• [Journal Article] Intrinsic Analysis of Radiative and Room-Temperature Nonradiative Processes Based on Triplet State Intramolecular Vibrations of Heavy Atom-Free Conjugated Molecules toward Efficient Persistent Room-Temperature Phosphorescence (2018)
  • Author(s): Shuzo Hirata
  • Journal Title: The Journal of Physical Chemistry Letters Volume: 9 Issue: 15 Pages: 4251-4259
  • DOI: 10.1021/acs.jpclett.8b01711
  • Peer Reviewed
• [Journal Article] Ultralong-Lived Room Temperature Triplet Excitons: Molecular Persistent Room Temperature Phosphorescence and Nonlinear Optical Characteristics with Continuous Irradiation (2018)
  • Author(s): Shuzo Hirata
  • Journal Title: Journal of Materials Chemistry Volume: 6 Issue: 44 Pages: 11785-11794
  • DOI: 10.1039/c8tc01417e
  • Peer Reviewed
• [Journal Article] Large Refractive Index Variations Induced by Accumulating Triplet Excitons under Photoexcitation at Low Power (2018)
  • Author(s): Tomoe Hori, Kenro Totani, Shuzo Hirata, Toshiyuki Watanabe
  • Journal Title: Chemical Physics Letters Volume: 704 Pages: 5-10
  • DOI: 10.1016/j.cplett.2018.05.029
  • Peer Reviewed
• [Presentation] Intrinsic analysis of transition processes from the lowest excited triplet state of heavy atom-free molecules with persistent room-temperature phosphorescence (2020)
  • Author(s): Shuzo Hirata
  • Organizer: SPIE Photonics Europe, Digital Forum
  • Int'l Joint Research / Invited
• [Presentation] SPIE Photonics Europe, Digital Forum (2019)
  • Author(s): Shuzo Hirata
  • Organizer: 2019 MRS Fall Meeting
  • Int'l Joint Research / Invited
• [Presentation] Donor-acceptor molecules showing photon upconversion emission by stepwise two photon absorption (2019)
  • Author(s): YOMOGITA Kentaro, ZHANG Junxiang, MIZUTANI Ryota, VAHCA Martin, KAMADA Kenji, MARDER Seth, HIRATA Shuzo
  • Organizer: Annual Meeting on Photochemistry 2019
• [Presentation] Analysis of Triplet State in Conjugated Molecular Crystals toward Persistent Room Temperature Phosphorescence from Soft Crystals (2019)
  • Author(s): Shuzo Hirata
  • Organizer: The 2nd International Symposium of Soft Crystals
  • Int'l Joint Research / Invited
• [Presentation] Exciton management for unique molecular emission characteristics (2019)
  • Author(s): Shuzo Hirata
  • Organizer: The 36th International Conference of Photopolymer Science and Technology (ICPST-36)
  • Int'l Joint Research / Invited
• [Presentation] Molecular Materials with Ultralong-Lived Room Temperature Triplet Excitons (2019)
  • Author(s): Shuzo Hirata
  • Organizer: 2019 International Seminar on Polymer Photochemistry (2019 ISPP)
  • Int'l Joint Research / Invited
• [Presentation] 分散系および凝集系における重原子フリー分子の三重項励起状態 (2019)
  • Author(s): 平田修造
  • Organizer: 141 M&BE 新分野開拓研究会「有機半導体制御技術の最新動向～分子配向・電荷・励起子～」
  • Invited
• [Presentation] 高効率分子蓄光に向けた三重項からの輻射と非輻射過程の解析 (2019)
  • Author(s): 平田修造
  • Organizer: 日本化学会第99回春季年会 特別企画 ルミネッセンス化学アンサンブル：発光の未来を探る
  • Invited
• [Presentation] 遷移双極子が小さい光学活性分子材料：円偏光遅延蛍光と円偏光室温蓄光 (2019)
  • Author(s): 平田修造
  • Organizer: 千葉大学分子キラリティーセンター定例研究会
  • Invited
• [Presentation] 分散系共役分子および凝集系共役分子結晶の室温長寿命三重項励起子のサイエンスと機能 (2018)
  • Author(s): 平田修造
  • Organizer: 東北大学PHyM若手フォーラム
  • Invited
• [Presentation] Intrinsic analysis of radiative process, intramolecular vibrational room-temperature nonradiative process, and quenching process from triplet state for heavy atom-free conjugated structures (2018)
  • Author(s): Shuzo Hirata
  • Organizer: Annual Meeting on Photochemistry on 2018
  • Invited
• [Presentation] Intrinsic Analysis between Radiative Process and Room-Temperature Nonradiative Process based on Intramolecular Vibrations from Triplet State of Heavy Atom-free Aromatics toward Efficient Persistent Room-temperature Phosphorescence (2018)
  • Author(s): Shuzo Hirata
  • Organizer: 2018 International Seminar on Advanced Materials Research 2018 ISAMR
  • Int'l Joint Research / Invited
• [Book] 環状高分子の合成と機能発現 (2018)
  • Author(s): 平田修造、バッハマーティン
  • Total Pages: 9
  • Publisher: シーエムシー出版
  • ISBN: 9784781313993
• [Patent(Industrial Property Rights)] 円偏光発光材料および円偏光発光材料を用いた物品 (2018)
  • Inventor(s): 平田修造 , 濱田雅裕 , 金子昌厳
  • Industrial Property Rights Holder: 平田修造 , 濱田雅裕 , 金子昌厳
  • Industrial Property Rights Type: 特許
  • Industrial Property Number: 2018-219440
  • Filing Date: 2018