Dynamics of transition-metal complex in supercritical CO_2 as studied by NMR
| Project/Area Number |
11440176
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical chemistry
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| Research Institution | Osaka University |
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Principal Investigator |
EGUCHI Taro Graduate School of Science, Osaka University, Professor, 大学院・理学研究科, 教授 (50107083)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA Hirokazu Kobe Pharmaceutical University, Associate Professor, 助教授 (40189080)
UEDA Takahiro Graduate School of Science, Osaka University, Research Associate, 大学院・理学研究科, 助手 (70294155)
MIYAKUBO Keisuke Graduate School of Science, Osaka University, Research Associate, 大学院・理学研究科, 助手 (70263340)
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| Project Period (FY) |
1999 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥15,400,000 (Direct Cost: ¥15,400,000)
Fiscal Year 2001: ¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 2000: ¥2,500,000 (Direct Cost: ¥2,500,000)
Fiscal Year 1999: ¥10,900,000 (Direct Cost: ¥10,900,000)
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| Keywords | Super-critical fluid / Xenon / Carbon dioxide / High pressure NMR / Porous materials / Molecular sieves / Catalysis / Dynamics / ポリマー / 遷移金属錯体 |
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| Research Abstract |
In 1999 we designed and built a new high-pressure NMR probe which can be used in a heterogeneous system under the supercritical condition of CO_2 (T_c = 31.0℃, P_c = 72.9atm). In situ NMR measurements can be performed in a temperature range between - 70 ℃ and + 150 ℃ , and in a pressure range below 20 MPa by using this probe.
^<129>Xe NMR was recorded on a Bruker MSL-200 spectrometer to investigate physico-chemical properties of micropores and/or mesopores in various porous systems. The critical parameters of Xe are Tc = 289.8 K, Pc = 5.8 MPa, and ρ_c = 1.15 gcm^<-3>.
At the first stage, we studied the free volumes in polymers which can adsorb Xe very weakly. The size of the micropore in each polymer was determined by ^<129>Xe NMR and was compared with the result of the positron annihilation experiment.
In the next stage, we applied the first high-pressure ^<129>Xe NMR to the meoporous silica, FSM-16. Three types of samples were used, which have different diameters (d) of the mesopore, being d = 1.9, 2.7, and 4.1 nm. It was found that there are two inequivalent Xe inside the mesopore with d = 1.9 nm. On the other hand, a single resonance line was observed in the mesopore with d = 4.1 nm. It was concluded that at least a diameter of d = 2.7 nm is necessary to detect the evidence of the critical phenomenon in the mesopore.
Finally we are now studying adsorption properties of molecular sieves 5A and 13X by using high-pressure ^<129>Xe NMR. It follows that not only water molecules inside the micropores but also the particle sizes affect Xe adsorption into these molecular sieves.
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Report
(4 results)
Research Products
(12 results)
