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PHOTOPHYSICS OF THE HIGHLY HINDERED MOLECULES STUDIED BY LASER PHOTOLYSIS

Research Project

Project/Area Number 62470008
Research Category

Grant-in-Aid for General Scientific Research (B)

Allocation TypeSingle-year Grants
Research Field 物理化学一般
Research InstitutionKyoto Institute of Technology

Principal Investigator

HAMANOUE Kumao  KYOTO INSTITUTE OF TECHNOLOGY, FACULTY OF ENGINEERING AND DESIGN, PROFESSOR, 工芸学部, 教授 (30025374)

Co-Investigator(Kenkyū-buntansha) USHIDA Kiminori  KYOTO INSTITUTE OF TECHNOLOGY, FACULTY OF ENGINEERING AND DESIGN, RESEARCH ASSOC, 工芸学部, 助手 (60183018)
西村 淳  京都工芸繊維大学, 工芸学部, 助教授 (10107352)
Project Period (FY) 1987 – 1989
Project Status Completed (Fiscal Year 1989)
Budget Amount *help
¥6,300,000 (Direct Cost: ¥6,300,000)
Fiscal Year 1989: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1988: ¥2,800,000 (Direct Cost: ¥2,800,000)
Fiscal Year 1987: ¥2,700,000 (Direct Cost: ¥2,700,000)
KeywordsLaser Spectroscopy / Highly Hindered MOlecules / High-sensitive Multi-channel Analyzer / Energy Relaxation Process / Rotational Relaxation Process / レーザー分光 / エネルギー緩和過程 / 高感度マルチチャネルアナライザー
Research Abstract

Combining a nanosecond ruby laser with a detection system (a polychromator and an image intensifier coupled with a linear position-sensitive detector) controlled by a personal computer, a convenient laser photolysis system was constructed. Using this system, we studied the photophysics of highly hindered molecules and the following results were obtained: (1) Multiple-components phosphorescences of 2,4,6-triisopropylbenzophenones at 77 K could be interpreted in terms of the existence of several conformers. (2) Triplet-triplet absorption spectra due to the lowest triplet (T_1) states of 2,4,6-triisopropylbenzophenones in solutions at room temperature shifted progressively to the blue with time on the subnanosecond time scale. This spectral shift was ascribed to the conformational change in the T_1 states. (3) Even for such a non-hindered molecule as methyl o-benzoylbenzoate, the existence of two T_1 states was observed at 77 K. (4) Phosphorescence spectra of 1,8-di-t-dutylanthraquinome, … More 1,2,3-tri-t-butylanthraquinone and 1,2-di-t-buty1-3-trimethylsilylanthraquinone were abnormally broad with short lifetimes of a few mus. These unusual T_1 states of pi pi^* or mixed npi^*-pi pi^* character were ascribed to the distortion of the geometrical structure of molecules. Although the transient absorption spectrum of 1,8-di-t-butylanthraquinone was assigned to a reaction intermediate, those of 1,2,3-tri-t-butylanthraquinone and 1,2-di-t-buty1-3-trimethylsilylanthraquinone were ascribed to the triplet-triplet absorptions.
We also obtained the following results: (5) In spite of a strong hydrogen-bonding ability of 2,2,2-trifltiorothanol (TFE), the phosphorescence spectra of anthraqtiinone, beta-halogenoanthraquinones, benzophenones, 1-indanone, flavone and flavanone in TFE at 77 K were identical with those in usual solvents. In contrast, the phosphorescence spectra in TFE/water could be interpreted in terms of the complex formation among triplet ketones, TFE and water(s), indicating that the change of the nature (or character) of pure solvents was not always the essential condition for interchanging the order of energy levels of triplet pi pi^* and pi pi^* states inherent to molecule itself. (6) From measurements of fluorescence and triplet-triplet absorption spectra of 9- and 9,10-dibromoanthracenes at various temperature, It was found that the direct intersystem crossing from the lowest excited singlet states to the T_1 states was the most important process to populate the T_1, state at low temperature (especially at 77 K). (7) For pliotochpmical reactions of 9-nitroanthracenes, it was confirmed that anthryloxy radicals as the reaction intermediates were produced via the higher excited triplet states of npi^* character. Less

Report

(4 results)
  • 1989 Annual Research Report   Final Research Report Summary
  • 1988 Annual Research Report
  • 1987 Annual Research Report
  • Research Products

    (28 results)

All Other

All Publications (28 results)

  • [Publications] Toshihiro Nakayama: "Phosphorescence and triplet-triplet absorption spectra of 1,2,3-tri-t-butylanthraquinone and 1,2-di-t-butyl-3-trimethylsilylanthraquinone" Chemical Physics Letters. 148. 259-263 (1988)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Kumao Hamanoue: "Role of water in the multiple-component phosphorescence of anthraquinone and beta-halogenoanthraquinone in 2,2,2-trifluoroethanol at 77 K" Journal of Physical Chemistry. 93. 3814-3818 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] K.Ushida: "Implementation of an image intensifier coupled with a linear position-sensitive detector for measurements of absorption and emission spectra from the nanosecond to millisecond time regime" Review of Scientific Instruments. 60. 617-623 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] 丑田公規: "ピコ秒およびナノ秒レ-ザ-分光による4'メトキシカルホニル-2,4,6-トリイソプロピルベンゾフェノン三重項状態の研究" 日本化学会誌. 1278-1284 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Toshihiro Nakayama: "Dual phosphorescence of benzophenone at 77 K in the mixed solvent of 2,2,2-trifluoroethanol and water" Chemical Physics Letters. 164. 557-561 (1989)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Toshihiro Nakayama: "Pulse radiolyses of anthraquinone and anthraquinone-triethylamine in acetonitrile and toluene at room temperature" Journal of Chemical Society,Faraday Transaction. 86. 95-103 (1990)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Toshihiro Nakayama: "Phosphorescence and triplet-triplet absorption spectra of 1,2,3-tri-t-butylanthraquinone and 1,2-di-t-butyl-3-trimethylsilylanthquinone" Chemical Physics Letters, 148, 259-263 (1988).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Kumao Hamanoue: "Role of water in the multiple-component phosphorescence of anthraquinone and beta-halogoanthraquinone in 2,2,2-trifluoroethanol at 77 K" Journal of Physical Chemistry 93, 3814-3818 (1989).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] K. Ushida: "Implementation of an image intensifier coupled with a linear position sensitive dector for measurements of absorption and emission spectra from the nanosecond to millisecond time regime" Review of Scientific Instruments 60, 617-623 (1989).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Kiminori Ushida: "Triplet state of 4'-methoxycarbonyl-2,4,6-triisopropylbenzophenone studied by pico- nanosecond laser spectroscopy" Journal of the Chemical Society of Japan, Chemistry and Industrial Chemistry, 1278-1284 (1989).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Toshihiro Nakayama: "Dual phosphorescence of benzophenone at 77 K in the mixed solvent of 2,2,2-triluoroethanol and water" Chemical Physics Letter, 164, 557-561 (1989).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Toshihiro Nakayama: "Pulse radiolyses of anthraquinone and anthraquinone-triethylamine in acetonitrile and toluene at room temperature" Journal of Chemical Society, Faraday Transaction 86, 95-103 (1990).

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      1989 Final Research Report Summary
  • [Publications] Kumao Hamanoue: "The role of water in the multiple-component phosphorescences of anthraquinone and β-halogenoanthraquinones in 2,2,2-trifluoroethanol at 77 K" Journal of Physical Chemistry. 93. 3814-3818 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] K.Ushida: "Implementation of an image intensifier coupled with a linear positionsensitive detector for measurements of absorption and emission spectra from the nanosecond to millisecond time regime" Review of Scientific Instruments. 60. 617-623 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] 丑田公規: "ピコ秒およびナノ秒レ-ザ-分光による4'ーメトキシカルボニルー2,4,6ートリイソプロピルベンゾフェノン三重項状態の研究" 日本化学会誌. 1278-1284 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Kiminori Ushida: "Construction of a Nd:glass laser photolysis system for the measurement of transient absorption spectra of excited molecules on a few picosecond time scale" Radiation Physics and Chemistry. 34. 465-475 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Toshihiro Nakayama: "Dual phosphorescence of benzophenone at 77 K in the mixed solvent of 2,2,2-trifluoroethanol and water" Chemical Physics Letters. 164. 557-561 (1989)

    • Related Report
      1989 Annual Research Report
  • [Publications] Toshihiro Nakayama: "Pulse radiolyses of anthraquinone and anthraquinone-triethylamine in acetonitrile and toluene at room temperature" Journal of Chemical Society,Faraday Transaction. 86. 95-103 (1990)

    • Related Report
      1989 Annual Research Report
  • [Publications] Toshihiro Nakayama: Chemical Physics Letters. 148. 259-263 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] Tosihiro Nakayama: Ultrafast Phenonema VI(Springer Series in Chemical Physics 48). 489-491 (1988)

    • Related Report
      1988 Annual Research Report
  • [Publications] Kumao Hamanoue: Journal of Physical Chemistry.

    • Related Report
      1988 Annual Research Report
  • [Publications] Kiminori Ushida: Review of Scientific Instruments.

    • Related Report
      1988 Annual Research Report
  • [Publications] Kiminori Ushida: Radiation Physics and Chemistry.

    • Related Report
      1988 Annual Research Report
  • [Publications] 丑田公規: 日本化学会誌.

    • Related Report
      1988 Annual Research Report
  • [Publications] Kumao Hamanoue: Bulletin of the Chemical Society of Japan.

    • Related Report
      1987 Annual Research Report
  • [Publications] Toshihira Nakayama: Chemical Physics Letters.

    • Related Report
      1987 Annual Research Report
  • [Publications] Kumao Hamanoue: Journal of the Chemical Society,Faraday Transaction II.

    • Related Report
      1987 Annual Research Report
  • [Publications] Kiminori Ushida: Radiation Physics and Chemistry.

    • Related Report
      1987 Annual Research Report

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Published: 1987-04-01   Modified: 2016-04-21  

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