Direct Observation of Photosynthesis in Chloroplast by Near-IR Vibrational Spectroscopy in Wide Time Range

• Project Area: Science on Function of Soft Molecular Systems by Cooperation of Theory and Experiment
• Project/Area Number: 16H00850
• Research Category: Grant-in-Aid for Scientific Research on Innovative Areas (Research in a proposed research area)
• Allocation Type: Single-year Grants
• Review Section: Science and Engineering
• Research Institution: Gakushuin University
• Principal Investigator: 高屋 智久 学習院大学, 理学部, 助教 (70466796)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Project Status: Completed (Fiscal Year 2017)
• Budget Amount: ¥6,630,000 (Direct Cost: ¥5,100,000、Indirect Cost: ¥1,530,000); Fiscal Year 2017: ¥3,380,000 (Direct Cost: ¥2,600,000、Indirect Cost: ¥780,000); Fiscal Year 2016: ¥3,250,000 (Direct Cost: ¥2,500,000、Indirect Cost: ¥750,000)
• Keywords: 時間分解分光 / 誘導ラマン分光 / 近赤外分光 / 励起状態動力学 / 生体分子

Outline of Annual Research Achievements

本研究課題は，光応答を示す生体分子の機能と構造の関係を明らかにするための実験手法として，フェムト秒～ミリ秒の時間領域で低侵襲的に分子構造を計測可能な時間分解近赤外誘導ラマン分光計を開発することを目的とする．本年度は分光計の開発に加え，カロテノイド主鎖末端の構造がカロテノイドの余剰エネルギー散逸速度にどのような影響を与えるかを調べる研究を行った．
まず，既設のフェムト秒時間分解近赤外マルチプレックス誘導ラマン分光計を拡張し，広時間域時間分解近赤外分光計を製作した．フェムト秒パルスレーザーと電気的に同期可能なサブナノ秒パルスレーザーを導入し，フェムト秒パルスレーザーからの同期信号のタイミングをデジタル遅延パルス発生器によって制御することで，ナノ秒～ミリ秒時間分解誘導ラマンスペクトルを測定可能とした．ペリレンジイミド誘導体のナノ秒時間分解近赤外吸収スペクトルを測定したところ，装置の時間分解能は約680 ps以下であった．以上により，100フェムト秒～1ミリ秒の時間分解誘導ラマンスペクトルを１台で観測可能な分光計が完成した．
前年度までの研究で，β-カロテンの末端にカルボニル基とヒドロキシ基が結合した誘導体であるアスタキサンチンが，β-カロテンよりも大きな振動エネルギー散逸速度定数を示すことが明らかとなった．本年度は，エネルギー散逸速度定数の増大の機構を明らかにするため，ヒドロキシ基のみ，あるいはカルボニル基のみが末端環に結合したβ-カロテン誘導体の時間分解近赤外誘導ラマンスペクトルを測定した．カルボニル基を有する誘導体についてのみ，無置換体よりも大きなエネルギー散逸速度定数が見られた．末端環平面と主鎖平面は互いにねじれているが，カルボニル基の導入によって2つの平面のなす二面角が減少し，主鎖の振動から末端環の振動へとエネルギーが効率良く再分配されることが明らかとなった．

Research Progress Status

29年度が最終年度であるため、記入しない。

Strategy for Future Research Activity

29年度が最終年度であるため、記入しない。

Research Products

• [Journal Article] Vibrational relaxation dynamics of β-carotene and its derivatives with substituents on terminal rings in electronically excited states as studied by femtosecond time-resolved stimulated Raman spectroscopy in the near-IR region (2018)
  • Author(s): Takaya Tomohisa、Anan Masato、Iwata Koichi
  • Journal Title: Physical Chemistry Chemical Physics Volume: 20 Issue: 5 Pages: 3320-3327
  • DOI: 10.1039/c7cp06343a
  • Peer Reviewed
• [Journal Article] Experimental and theoretical investigation of fluorescence solvatochromism of dialkoxyphenyl-pyrene molecules (2018)
  • Author(s): Lu Fengniu、Kitamura Naoki、Takaya Tomohisa、Iwata Koichi、Nakanishi Takashi、Kurashige Yuki
  • Journal Title: Physical Chemistry Chemical Physics Volume: 20 Issue: 5 Pages: 3258-3264
  • DOI: 10.1039/c7cp06811e
  • Peer Reviewed
• [Journal Article] The effect of regioisomerism on the photophysical properties of alkylated-naphthalene liquids (2018)
  • Author(s): Narayan B.、Nagura K.、Takaya T.、Iwata K.、Shinohara A.、Shinmori H.、Wang H.、Li Q.、Sun X.、Li H.、Ishihara S.、Nakanishi T.
  • Journal Title: Physical Chemistry Chemical Physics Volume: 20 Issue: 5 Pages: 2970-2975
  • DOI: 10.1039/c7cp05584f
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] A Guide to Design Functional Molecular Liquids with Tailorable Properties using Pyrene-Fluorescence as a Probe (2017)
  • Author(s): Fengniu Li, Tomohisa Takaya, Koichi Iwata, Izuru Kawamura, Akinori Saeki, Masashi Ishii, Kazuhiko Nagura, Takashi Nakanishi
  • Journal Title: Scientific Reports Volume: 7 Issue: 1 Pages: 3416-3416
  • DOI: 10.1038/s41598-017-03584-1
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Development of a femtosecond time-resolved near-IR multiplex stimulated Raman spectrometer in resonance with transitions in the 900-1550 nm region (2016)
  • Author(s): Tomohisa Takaya, Koichi Iwata
  • Journal Title: Analyst Volume: 141 Issue: 14 Pages: 4283-4292
  • DOI: 10.1039/c6an01051b
  • Peer Reviewed / Acknowledgement Compliant
• [Presentation] Femtosecond Time-Resolved Near-IR Stimulated Raman Studies of Structural Relaxation in pi-Conjugated Compounds (2018)
  • Author(s): Tomohisa Takaya
  • Organizer: The 10th Asian Conference on Ultrafast Phenomena
  • Int'l Joint Research / Invited
• [Presentation] Structural Relaxation Dynamics of Poly(p-phenylenevinylene) Derivative in Solution: Direct Observation by Ultrafast Near-IR Spectroscopy (2017)
  • Author(s): Tomohisa Takaya, Masanori Shinohara, and Koichi Iwata
  • Organizer: 日本化学会第97春季年会
  • Place of Presentation: 慶応大学日吉キャンパス（神奈川県横浜市）
  • Year and Date: 2017-03-16
• [Presentation] ピレン励起ダイナミクスの超高速分光計測と解析によるアルキル化π液体分子に潜む「柔らかさ」の起源探求（２） (2017)
  • Author(s): 中西尚志，高屋智久
  • Organizer: 日本化学会第97春季年会
  • Place of Presentation: 慶応大学日吉キャンパス（神奈川県横浜市）
  • Year and Date: 2017-03-16
  • Invited
• [Presentation] Ultrafast near-IR stimulated Raman spectroscopy of photoexcited pi-conjugate molecules in solution (2017)
  • Author(s): Tomohisa Takaya
  • Organizer: International Symposium on Ultrafast Dynamics in Molecular and Material Sciences
  • Place of Presentation: 岡崎コンファレンスセンター（愛知県岡崎市）
  • Year and Date: 2017-03-06
  • Int'l Joint Research / Invited
• [Presentation] β-ヨノン環に置換基を有する4種のカロテノイドの内部転換および振動エネルギー緩和速度の検討 (2017)
  • Author(s): 阿南真郷，高屋智久，岩田耕一
  • Organizer: 第11回分子科学討論会
• [Presentation] Femtosecond Time-Resolved Near-IR Inverse Raman Spectroscopy and Its Application to Carrier Dynamics in Poly(3-hexylthiophene) Thin Films (2017)
  • Author(s): Tomohisa Takaya, Ippei Enokida, Yukio Furukawa, Koichi Iwata
  • Organizer: The XVIIIth International Conference on Time-Resolved Vibrational Spectroscopy
  • Int'l Joint Research
• [Presentation] Electronic and Structural Dynamics of Photoexcited pi-Conjugate Polymers in Solution as studied by Ultrafast Near-IR Absorption and Stimulated Raman Spectroscopy (2016)
  • Author(s): Tomohisa Takaya, Masanori Shinohara, and Koichi Iwata
  • Organizer: EMN Meeting on Ultrafast 2016
  • Place of Presentation: Mantra Bell City (Melbourne, Australia)
  • Year and Date: 2016-10-10
  • Int'l Joint Research / Invited
• [Presentation] Development of Femtosecond Time-Resolved Multiplex Near-IR Stimulated Raman Spectrometer in 1.0-1.6 um Region (2016)
  • Author(s): Tomohisa Takaya and Koichi Iwata
  • Organizer: The 4th Taiwan International Symposium on Raman Spectroscopy
  • Place of Presentation: National Taiwan University (Taipei, Taiwan)
  • Year and Date: 2016-06-28
  • Int'l Joint Research / Invited
• [Presentation] Partial Charge Separation Dynamics in pi-Conjugate Systems Probed by Ultrafast Near-IR Spectroscopy (2016)
  • Author(s): Tomohisa Takaya
  • Organizer: The 20th East Asian Workshop on Chemical Dynamics
  • Place of Presentation: National Sun Yat-sen University (Kaohsiung, Taiwan)
  • Year and Date: 2016-06-12
  • Int'l Joint Research / Invited