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Aqueous Solution Chemistry at Supercritical Conditions

Research Project

Project/Area Number 10304047
Research Category

Grant-in-Aid for Scientific Research (A).

Allocation TypeSingle-year Grants
Section一般
Research Field Physical chemistry
Research InstitutionKYOTO UNIVERSITY

Principal Investigator

NAKAHARA Masaru  Institute for Chemical Research, KYOTO UNIVERSITY, Professor, 化学研究所, 教授 (20025480)

Co-Investigator(Kenkyū-buntansha) WAKAI Chiniro  Institute for Chemical Research, KYOTO UNIVERSITY, Associate Instructor, 化学研究所, 教務職員 (40293948)
OKAMURA Emiko  Institute for Chemical Research, KYOTO UNIVERSITY, Associate Instructor, 化学研究所, 教務職員 (00160705)
MATUBAYASI Nobuyuki  Institute for Chemical Research, KYOTO UNIVERSITY, Instructor, 化学研究所, 助手 (20281107)
Project Period (FY) 1998 – 2000
Project Status Completed (Fiscal Year 2000)
Budget Amount *help
¥26,600,000 (Direct Cost: ¥26,600,000)
Fiscal Year 2000: ¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 1999: ¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 1998: ¥19,200,000 (Direct Cost: ¥19,200,000)
Keywordssupercritical water / subcritical water / chemical shift / NMR relaxation / computer simulation / dipole moment / noncatalytic reactions / dissociated proton / 回転ダイナミクス / 速度定数 / ギ酸 / エーテル / 水素結合 / NMR / 水熱反応 / 水性ガスシフト反応 / ジクロロメタン / その場観察 / プロトンNMR
Research Abstract

The proton chemical shift of water is measured over a wide range of temperatures and densities. It is then found that the hydrogen bonding persists at supercritical temperatures and that the average number of hydro gen bonds is at least one for a water molecule in the supercritical densities. The density dependence of the chemical shift at a supercritical temperature shows that the hydrogen bonding is spatially more inhomogeneous at lower densities. The dipole moment of a water molecule at supercritical states is further estimated within the SPC-like and TIP4P-like frameworks of the water intermolecular potential model.
The rotational dynamics of water in super- and subcritical conditions is investigated by measuring the spin-lattice relaxation time T_1 of heavy water (D_2O). The experimentally determined T_1 is shown to be governed by the quadrupolar relaxation mechanism even in the supercritical conditions. It is then found that the reorientational correlation time remains on the order of several tens of femtoseconds when the density is varied up to twice the critical at a fixed supercritical temperature of 400℃. The comparison of the reorientational correlation time with the angular momentum correlation time shows that the rotational dynamics is not diffusive in supercritical water.
Noncatalytic reactions at hydrothermal conditions are investigated systematically. By focusing the dehydration of 1,4-butanediol into tetrahydrofuran, we determined the effect of the dissociated proton in hot water. It is widely believed that a reaction which is acid-catalyzed in ambient conditions is accelerated in hydrothermal conditions due to the increased concentration of dissociated proton. In our reaction system, we kept the density and temperature constant and varied the proton concentration by adding hydrochloric acid. We then determined the noncatalytic effect on the reaction and found that water at hydrothermal conditions promotes the reaction in its neutral form.

Report

(4 results)
  • 2000 Annual Research Report   Final Research Report Summary
  • 1999 Annual Research Report
  • 1998 Annual Research Report
  • Research Products

    (30 results)

All Other

All Publications (30 results)

  • [Publications] Matubayasi N,Wakai C, and Nakahara M: "Structural Study of Supercritical Water II. Computer Simulations"Journal of Chemical Physics. 110. 8000-8011 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Tsujino Y,Wakai C,Matubayasi N,and Nakahara M: "Noncatalytic Cannizzaro-type Reaction of Formaldehyde in Hot Water"Chemistry Letters. 1999. 287-288 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Bossev DP,Matsumoto M,and Nakahara M: "^9F NMR Study of Molecular Aggregation of Lithium Perfluorooctylsulfonate in Water at Temperatures from 30 to 250℃"Journal of Physical Chemistry B. 104. 155-158 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N and Nakahara M: "Super-and Subcritical Hydration of Nonpolar Solutes.I. Thermodynamics of Hydration"Journal of Chemical Physics. 112. 8089-8109 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N and Nakahara M: "Association and Dissociation of Nonpolar Solutes in Super-and Subcritical Water"Journal of Physical Chemistry B. 104. 10352-10358 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N,Nakao N,and Nakahara M: "Structural Study of Supercritical Water III.Rotational Dynamics"Journal of Chemical Physics. 114. 4107-4115 (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N, Wakai C, and Nakahara M: "Structural Study of Supercritical Water II.Computer Simulations"Journal of Chemical Physics. 110. 8000-8011 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Tsujino Y, Wakai C, Matubayasi N, and Nakahara M: "Noncatalytic Cannizzaro-type Reaction of Formaldehyde in Hot Water"Chemistry Letters. 1999. 287-288 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Bossev DP, Matsumoto M, and Nakahara M: "^9F NMR Study of Molecular Aggregation of Lithium Perfluorooctylsulfonate in Water at Temperatures from 30 to 250℃"Journal of Physical Chemistry B. 104. 155-158 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N and Nakahara M: "Super- and Subcritical Hydration of Nonpolar Solute. I.Thermodynamics of Hydration"Journal of Chemical Physics. 112. 8089-8109 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N and Nakahara M: "Association and Dissociation of Nonpolar Solutes in Super- and Subcritical Water"Journal of Physical Chemistry B. 104. 10352-10358 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N, Nakao N, and Nakahara M: "Structural Study of Supercritical Water III.Rotational Dynamics"Journal of Chemical Physics. 114. 4107-4115 (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Matubayasi N and Nakahara M: "Super- and Subcritical Hydration of Nonpolar Solutes.I.Thermodynamics of Hydration"Journal of Chemical Physics. 112. 8089-8109 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Matubayasi N and Nakahara M: "Theory of Solutions in the Energetic Representation.I.Formulation"Journal of Chemical Physics. 113. 6070-6081 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Bossev DP,Matsumoto M,and Nakahara M: "^<19>F NMR Study of Molecular Aggregation of Lithium Perfluorooctylsulfonate in Water at Temperatures from 30 to 250℃"Journal of Physical Chemistry B. 104. 155-158 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Matubayasi N and Nakahara M: "Association and Dissociation of Nonpolar Solutes in Super- and Subcritical Water"Journal of Physical Chemistry B. 104. 10352-10358 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Yamasaki Y,Enomoto H,Yamasaki N,and Nakahara M: "NMR Study of Hydrothermal Reactions of Dichloromethane with and without Alkali"Bulletin of the Chemical Society of Japan. 73. 2687-2693 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Matubayasi N,Nakao N,and Nakahara M: "Structural Study of Supercritical Water III.Rotational Dynamics"Journal of Chemical Physics. 114. 4107-4115 (2001)

    • Related Report
      2000 Annual Research Report
  • [Publications] 松林 伸幸: "Super-and subcritical hydration of nonpolar solutes. I.Thermodynamics of hydration"Journal of Chemical Physics. 112. 印刷中 (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] 中原 勝: "Fundamental Knowledge of Supercritical Water and its Application to Polymer Chemistry"Cellulose Communications. 6. 60-66 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] 中原 勝: "超臨界水の物性と構造"電気化学及び工業物理化学. 67. 988-993 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] 若井 千尋: "Pressure Effect on Rotational Dynamics of Hydrophobic Hydration. Rotational Dynamics of Benzene"Journal of Physical Chemistry. A103. 6685-6690 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Dobrin P.Bossev: "^1H and ^<19>FNMR Study of the Counterion Effect on the Micellar Structures Formed by Tetraethylammonium and Lithiu Perfluorooctylsulfonates. 1. Neat Systems"Journal of Physical Chemistry. B103. 8251-8258 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Dobrin P.Bossev: "^1H and ^<19>FNMR Study of the Counterion Effect on the Micellar Structures Formed by Tetraethylammonium and Lithiu Perfluorooctylsulfonates. 2. Mixed Systems"Journal of Physical Chemistry. B103. 8259-8266 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] N.Matubayasi et al.: "NMR Study of Water Structure in Supercritical Conditions" Rev.High Pressure Sci.Technol.第7巻. 1112-1114 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] T.Tennoh et al.: "Supercritical Water Cracking and Washing of Used Polymer" Rev.High Presure Sci.Technol.第7巻. 1429-1431 (1998)

    • Related Report
      1998 Annual Research Report
  • [Publications] Yuki Yamasaki et al.: "Methanol Formation from Dichlorome thane under Hydrothermal Conditions" Chem.Lett.1999巻. 83-84 (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] Nobuyuki Matubayasi et al.: "Reversible molecular dynamics for rigid bodies and hybrid Mante Carlo" J.Chem.Phys.110巻. 3291-3301 (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] Nobuyuki Matubayasi et al.: "Structural Study of Supercritical Water II.Computer simulations" J.Chem.Phys.110巻4/22号(in press). (1999)

    • Related Report
      1998 Annual Research Report
  • [Publications] Yasuo Tsujino et al.: "Noncatalytic Cannizzaro-type Reaction of Formablehyde in Hot Water" Chem.Lett.1999巻4月号(in press). (1999)

    • Related Report
      1998 Annual Research Report

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Published: 1998-04-01   Modified: 2016-04-21  

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