| Project/Area Number |
62470041
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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 |
無機・錯塩・放射化学
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| Research Institution | Nagoya University |
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Principal Investigator |
FUNAHASHI Shigenobu Nagoya University, Associate Professor, 理学部, 助教授 (30022700)
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| Project Period (FY) |
1987 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥5,500,000 (Direct Cost: ¥5,500,000)
Fiscal Year 1988: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1987: ¥4,800,000 (Direct Cost: ¥4,800,000)
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| Keywords | solvent exchange / complexation / pressure effect / activation volume / 金属錯体 / 反応体積 |
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| Research Abstract |
Solvent exchange and complex formation with respect to metal ions are the fundamental phenomena in solution and dynamic studies on such processes sre very inportant for elucidating the mechanism. The activation volume has proved to be particularly diagnostic of activation mode. Therefore, the pressure effect on rates for their reactions has been investigated as follows.
1. activation volumes for ethylenediamine exchange on Ni(II) and Cu(II) ions has been determined to be 13 and 4.0 cm^3 mol^<-1>,respectively, by the high-pressure ^<14>N-NMR method.
2. The activation parameters for the exchange reaction of several nitriles at Ni(II) ion have been detemined by the ^<14>N-NMR line broadening method. The activation volume (ca. 13 cm^3 mol^<-1>) varies little in spite of the large variation of the molar volume of nitriles. The mechanism of the nitrile exchange at Ni(II) ion is of the similar dissociative character for different nitriles of different bulkiness.
3. Solvent exchange on the iron(III)-PhDTA complex has been studied as a function of temperature and pressure. The activation parameters indicate greater lability of coordinated solvent molecule on the complex. A positive value of activation volume indicates the dissociative-interchange mechanism.
4. Complexation of tetrahedral beryllium(II) ion in DMF and tetramethylurea(TMU) and complexation of planer boric acid in water have been studied by the high-pressure stopped-flow method. The fact that the activation volume is negative in DMF and positive in bulkier TMU indicates that the mechanism is changable from associative to dissociative due to bulkiness of coordinated solvents. The structural change of boric acid from a trigonal to a tetrahedron is rate determining.
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