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Structures and Reactivities of Negatively-Charged Clusters in Supercritical Carbon Dioxide

Research Project

Project/Area Number 12440160
Research Category

Grant-in-Aid for Scientific Research (B)

Allocation TypeSingle-year Grants
Section一般
Research Field Physical chemistry
Research InstitutionThe University of Tokyo

Principal Investigator

NAGATA Takashi  The University of Tokyo, Graduate School of Arts and Sciences, Professor, 大学院・総合文化研究科, 教授 (10164211)

Co-Investigator(Kenkyū-buntansha) ITOH Kengo  The University of Tokyo, Graduate School of Arts and Sciences, Research assistant, 大学院・総合文化研究科, 助手 (40221080)
WATANABE Kazuo  The University of Tokyo, Graduate School of Arts and Sciences, Research assistant, 大学院・総合文化研究科, 助手 (90312206)
Project Period (FY) 2000 – 2002
Project Status Completed (Fiscal Year 2002)
Budget Amount *help
¥9,600,000 (Direct Cost: ¥9,600,000)
Fiscal Year 2002: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2001: ¥2,600,000 (Direct Cost: ¥2,600,000)
Fiscal Year 2000: ¥5,400,000 (Direct Cost: ¥5,400,000)
KeywordsSupercritical carbon dioxide / Mobility measurement / Negatively-charged clusters / Ab initio calculations / Photodestruction spectrum / Radical reactions / Negative-ion chemistry / 局所クラスター構造 / 電子束縛状態 / イオン移動度 / クラスター構造
Research Abstract

The present study aims for (i) the spectroscopic detection of (CO_2)_n^-clusters formed in a supercritical carbon dioxide (hereafter referred to as {(CO_2)_n^-}_<scf>) and (ii) the systematic study of reactivities of {(CO_2)_n^-}_<scf> in order to explore the negative-ion chemistry in supercritical carbon dioxide. The findings are summarized as follows :
1.The formation of {(CO_2)_n^-}_<scf> is detected by the measurement of negative charge transport in gaseous, supercritical and liquid carbon dioxide. The mobility measurement over a wide range of CO_2 density revealed that the nascent {(CO_2)_n^-}_<scf> formed around the excess electrons are primarily in the size range of n = 5 -6, and that the negative charge transport occurs with both the hopping and the conduction band mechanisms.
2.The electronic and geometrical structures of (CO_2)_n^-and [(CO_2)_n^-(H_2O)_m] are investigated by ab initio calculations at MP2/6-311++G(d, p) level for small clusters and MP2/6-31 for larger ones, demo … More nstrating the existence of almost-isoenergetic isomers having different electronic structures ("electronic isomers").
3.An effort has been made to probe the nascent {(CO_2)_n^-}_<scf> formed in a supercritical pure carbon dioxide by ns time-resolved photoabsorption spectroscopy. The transient photoabsorption signal has not been detected due possibly to either small quantum yield for the {(CO_2)_n^-}_<scf> formation or small cross sections for the {(CO_2)_n^-} photoabsorption.
4.The photodestruction spectra of (CO_2)_n^-are measured in the visible and uv regions by means of photofragment mass spectrometry, which provide information on the fundamental electronic properties of (CO_2)_n^-species.
5.Mass spectrometric studies have revealed the reactivity of gas-phase (CO_2)_n^-and CO_2^-(H_2O)_n as carboxylation reagents for alkyl halides and conjugated alkenes. The hydration stabilizes CO_2^<・-> without deteriorating its radical reactivity. These findings open up a possibility of novel {(CO_2)_n^-}_<scf> chemistry in a supercritical carbon dioxide. Less

Report

(4 results)
  • 2002 Annual Research Report   Final Research Report Summary
  • 2001 Annual Research Report
  • 2000 Annual Research Report
  • Research Products

    (27 results)

All Other

All Publications (27 results)

  • [Publications] R.A.Hoiroyd et al.: "Solvent clustering around pyrazine ions in the high-compressibility region of supercritical ethane"Journal of Physical Chemistry. B104. 11585-11590 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M.Saeki et al.: "Ab initio study of (CO_2)_n^- : structures and stabilities of isomers"Chemical Physics Letters. 340. 376-384 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M.Saeki et al.: "Ab initio study of CO_2^-・CO_2【tautomer】C_2O_4^- isomerization"Chemical Physics Letters. 348. 461-468 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] L.Zhu et al.: "Photodissociation of gas-phase I_3^- : product branching in the visible and uv regions"Chemical Physics Letters. 350. 233-239 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] K.Itoh et al.: "Ion mobilities in supercritical ethane, xenon, and carbon dioxide"Chemical Physics Letters. A105. 703-709 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] T.Tsukuda et al.: "Photochemistry of (NO)_n^- as studied by photofragment mass spectrometry"International Journal of Mass Spectrometry. 220. 137-143 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Y.Negishi et al.: "Structural evolution in (CO_2)_n clusters (n<10^3) as studied by mass spectrometry"Chemical Physics Letters. 364. 127-132 (2002)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] T.Tsukuda et al.: "Gas-phase reaction of hydrated CO_2^<・-> anion radical with CH_3I"Journal of Physical Chemistry. A107. 8476-8483 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] R.A.Holroyd et al.: "Reactions of charged species in supercritical xenon as studied by pulse radiolysis"Journal of Physical Chemistry. B107. 7281-7287 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] R.A.Holroyd et al.: "Density inhomogeneities and electron mobility in supercritical xenon"Journal of Chemical Physics. 118. 706-710 (2003)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] R.A.Holroyd, M.Nishikawa, K.Itoh: "Solvent clustering around pyrazine ions in the high-compressibility region of supercritical ethane"Journal of Physical Chemistry. B104. 11585-11590 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M.Saeki, T.Tsukuda, T.Nagata: "Ab initio study of (CO_2)_n^-:structures and stabilities of isomers"Chemical Physics Letters. 340. 376-384 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] M.Saeki, T.Tsukuda, T.Nagata: "Ab initio study of CO ・CO_2 【tautomer】 C_2O_4 isomerization"Chemical Physics Letters. 348. 461-468 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] L.Zhu, K.Takahashi, M.Saeki, T.Tsukuda, T.Nagata: "Photodissociation of gas-phase I_3^-: product branching in the visible and uv regions"Chemical Physics Letters. 350. 233-239 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] K.Itoh, R A.Hoiroyd, M.Nishikawa: "Ion mobilities in supercritical ethane, xenon, and carbon dioxide"Journal of Physical Chemistry. A105. 703-709 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] T.Tsukuda, L.Zhu, M.Saeki, T.Tsukuda, T Nagata: "Photochemistry of (NO)_n^-as studied by photofragment mass spectrometry"International Journal of Mass Spectrometry. 220. 137-143 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Y.Negishi, T.Nagata, T.Tsukuda: "Structural evolution in (CO_2)_n clusters (n<10^3) as studied by mass spectrometry"Chemical Physics Letters. 364. 127-132 (2002)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] T.Tsukuda, T Nagata: "Gas phase reaction of hydrated CO_2^<・-> anion radical with CH_3I"Journal of Physical Chemistry. A107. 8476-8483 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] R.A.Holroyd, J.F.Wishart, M.Nishikawa, K.Itoh: "Reactions of charged species in supercritical xenon as studied by pulse radiolysis"Journal of Physical Chemistry. B107. 7281-7287 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] R.A.Holroyd, K.Itoh, M.Nishikawaet: "Density inhomogeneities and electron mobility in supercritical xenon"Journal of Chemical Physics. 118. 706-710 (2003)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2002 Final Research Report Summary
  • [Publications] Y.Negishi et al.: "Structural evolution in (CO_2)_n clusters (n<10^3) as studied by mass spectrometry"Chemical Physics Letters. 364. 127-132 (2002)

    • Related Report
      2002 Annual Research Report
  • [Publications] R.A.Holroyd et al.: "Density inhomogeneities and electron mobility in supercritical xenon"Journal of Chemical Physics. 118. 706-710 (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] R.A.Holroyd et al.: "Reactions of charged species supercritical xenon as studied by pulse radiolysis"Journal of Physical Chemistry. (印刷中). (2003)

    • Related Report
      2002 Annual Research Report
  • [Publications] M.Saeki, et al.: "Ab initio study of (CO_2)_n^-: structures and stabilities of isomers"Chemical Physics Letters. 340. 376-384 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] M.Saeki, et al.: "Ab initio study of CO_2^-・CO_2 【tautomer】 C_2O_4^- isomerization"Chemical Physics Letters. 348. 461-468 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] K.Itoh, et al.: "Ion mobilities in supercritical ethane, xenon, and carbon dioxide"Journal of Physical Chemistry. A105. 703-709 (2001)

    • Related Report
      2001 Annual Research Report
  • [Publications] M.Saeki et al.: "Ab initio study of (CO_2)_n^- : structures and stabilities of isomers"Chemical Physics Letters. (印刷中). (2001)

    • Related Report
      2000 Annual Research Report

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Published: 2000-04-01   Modified: 2016-04-21  

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