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Direct Detection of Singlet Molecular Oxygen by Electron Paramagnetic Resonance and Development of a New Quantitative Method for the Concentration Measurement

Research Project

Project/Area Number 15550009
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Physical chemistry
Research InstitutionNational University Corporation Yokohama National University

Principal Investigator

YAGI Mikio  National University Corporation Yokohama National University, Graduate School of Engineering, Professor, 大学院・工学研究院, 教授 (00107369)

Project Period (FY) 2003 – 2004
Project Status Completed (Fiscal Year 2004)
Budget Amount *help
¥3,800,000 (Direct Cost: ¥3,800,000)
Fiscal Year 2004: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2003: ¥3,000,000 (Direct Cost: ¥3,000,000)
Keywordssinglet molecular oxygen / reactive oxygen species / electron paramagnetic resonance / photosensitized reaction / energy transfer / excited state / 一重項酸素 / 活性酸素種 / 三重項状態 / オクタフオロナフタレン
Research Abstract

The lowest electronically excited singlet state of oxygen molecule, O_2(^1Δ_g), has been a subject of study for many years, with particular interest being taken in many photochemical and biological problems. O_2(^1Δ_g) is an active intermediate in the photooxygenation reactions. It is important to measure the concentration of O_2(^1Δ_g) for most applications requiring O_2(^1Δ_g) as a reactive intermediate. Since the ground-state oxygen molecule, O_2(^3Σ_g^-), is recommended as a quantitative standard, the most reliable technique for determining O_2(^1Δ_g) concentration has been electron paramagnetic resonance(EPR) spectroscopy. Oxygen in the ^1Δ_g state can be detected using the EPR technique, because O_2(^1Δ_g) is paramagnetic owing to its orbital angular momentum.
O_2(^1Δ_g) molecules were generated from O_2(^3Σ_g^-) by gas-phase energy transfer from the excited triplet states of the sensitizer molecules. Naphthalene, 1-fluoronaphthalene, octafluoronaphthalene, and benzophenone were u … More sed as the sensitizer. The EPR spectra were measured at room temperature by a JEOL JES-FA200 X-band spectrometer equipped with a homemade 100 kHz power amplifier and a Varian V-4535 large sample access cylindrical cavity. The excitations were carried out using a Canrad-Hanovia 1 kW Xe-Hg arc lamp.
The characteristic nearly symmetrical four-line EPR spectrum of O_2(^1Δ_g) was observed at about 1 T during excitation. The EPR signals of O_2(^3Σ_g^-) decreased immediately with rise of O_2(^1Δ_g) signals on excitation. After shutting off the exciting light, the O_2(^3Σ_g^-) signals rose and the O_2(^1Δ_g) signals disappeared. These results show that the loss of O_2(^3Σ_g^-) on excitation is negligible compared to the amount of produced O_2(^1Δ_g). We can safely assume that the amount of O_2 in some metastable state other than ^1Δ_g is negligible. Therefore we estimated the concentration of O_2(^1Δ_g) directly. Under our experimental conditions, the steady-state O_2(^1Δ_g) concentration of 40% was obtained by the photosensitization with octafluoronaphthalene at low pressures, 【approximately equal】0.3 Torr. Less

Report

(3 results)
  • 2004 Annual Research Report   Final Research Report Summary
  • 2003 Annual Research Report
  • Research Products

    (9 results)

All 2005 2004 Other

All Journal Article (8 results) Publications (1 results)

  • [Journal Article] Time-Resolved Electron Paramagnetic Resonance of the Lowest Excited Triplet State of Phenazinium Cation2005

    • Author(s)
      出口 誠
    • Journal Title

      Spectrochimica Acta Part A 61

      Pages: 1147-1151

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Time-Resolved Electron Paramagnetic Resonance of the Lowest Excited Triplet State of Phenazinium Cation2005

    • Author(s)
      Deguchi, Makoto
    • Journal Title

      Spectrochimica Acta Part A 61

      Pages: 1147-1151

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Time-Resolved Electron Paramagnetic Resonance of the Lowest Excited Triplet State of Phenazinium Cation2005

    • Author(s)
      出口 誠
    • Journal Title

      Spectrochimica Acta Part A : Molecular and Bimolecular Spectroscopy 61

      Pages: 1147-1151

    • Related Report
      2004 Annual Research Report
  • [Journal Article] Specific Deuterium Isotope Effects on the Intramolecular Charge-Transfer Dynamics of 4-(Dimethylamino)benzonitrile2004

    • Author(s)
      岩瀬 英二郎
    • Journal Title

      Physical Chemistry Chemical Physics 6

      Pages: 3852-3856

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Annual Research Report 2004 Final Research Report Summary
  • [Journal Article] Measurement of Concentration of Singlet Molecular Oxygen in the Gas Phase by Electron paramagnetic Resonance2004

    • Author(s)
      八木 幹雄
    • Journal Title

      Chemistry Letters 33

      Pages: 152-153

    • NAID

      10012042678

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Specific Deuterium Isotope Effects on the Intramolecular Charge-Transfer Dynamics of 4-(Dimethylamino)benzonitrile2004

    • Author(s)
      Iwase, Eijiro
    • Journal Title

      Physical Chemistry Chemical Physics 6

      Pages: 3852-3856

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of Concentration of Singlet Molecular Oxygen in the Gas Phase by Electron Paramagnetic Resonance2004

    • Author(s)
      Yagi, Mikio
    • Journal Title

      Chemistry Letters 23

      Pages: 152-153

    • NAID

      10012042678

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2004 Final Research Report Summary
  • [Journal Article] Measurement of Concentration of Singlet Molecular Oxygen in the Gas Phase by Electron Paramagnetic Resonance2004

    • Author(s)
      八木 幹雄
    • Journal Title

      Chemistry Letters 33

      Pages: 152-153

    • NAID

      10012042678

    • Related Report
      2004 Annual Research Report
  • [Publications] 八木 幹雄, 竹本 正悟, 笹瀬 良治: "Measurement of Concentration of Singlet Molecular Oxygen in the Gas Phase by Electron Paramagnetic Resonance"Chemistry Letters. 33. 152-153 (2004)

    • Related Report
      2003 Annual Research Report

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Published: 2003-04-01   Modified: 2016-04-21  

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