| Project/Area Number |
04453015
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
構造化学
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| Research Institution | Osaka University |
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Principal Investigator |
NAKAMURA Nobuo College of General Education, Osaka University, Professor, 教養部, 教授 (70028166)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAYAMA Hirokazu College of General Education, Osaka University, Research Associate, 教養部, 助手 (40189080)
EGUCHI Taro College of General Education, Osaka University, Associate Professor, 教養部, 助教授 (50107083)
TAKEDA Sadamu Faculty of Science, Osaka University, Research Associate, 理学部, 助手 (00155011)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1993: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1992: ¥6,000,000 (Direct Cost: ¥6,000,000)
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| Keywords | Double resonance / Nuclear quadrupole interaction / Thermochromism / Hydrogen bond / 核磁気共鳴 / 二重共鳴 |
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| Research Abstract |
Thermochromism has recently been attracted much interest with respect to its molecular mechanisms. In order to investigate the molecular basis of the thermochromism by means of nuclear quadrupole resonance of the oxygen-17 nucleus in thermochromic materials we designed and constructed a ^<17>O-^1H nuclear double resonance spectrometer on the basis of Slusher-Hahn double resonance principle. It observes the existence and the degree of polarization transfer from rare spin systems such as ^<17>O and ^<14>N to proton at zero magnetic field.
The apparatus consists of Oxford superconducting magnet (the field is 4.7 T, ^1H resonance at 200Mhz), Bruker MSL-200NMR system which observe the proton nuclear magnetic resonance spectrum, a sample shooting system into zero-fields pace in a few seconds, and the small solenoid magnet for eliminating the residual magnetic field of an amount of about 10 mT.The latter two systems were constructed and tested the last year. An L-C matching unit to supply the
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radio-frequency magnetic field for the low-frequency nuclear quadrupole resonance was constructed.
The double resonance experiments search the reduction of the proton resonace signal due to the polrization-transfer from the rare spin system to the proton spins by sweeping the low-frequency quadrupole resonance frequency ; whole experimental procedures were automated by the use of a personal computer system the program for which was coded by the BASIC and the assembler languages. The data analysis were performed by means of a work station.
The double resonance system described above was used to observe successfully the pure nuclear quadrupole resonance signals of ^<14>N in crystalline acetamide ; however, we could neither observe any significant signals of ^<17>O nor ^<14>N in N-salicylideneaniline which is typical thermochromic material. The failure may be attributed to significantly large scattering of data due to very poor proton signal and to rapid self-reduction of the proton signal caused by efficient relaxation rate, which concealed the effective reduction of the proton signal by the polarization transfer. Less
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