1989 Fiscal Year Final Research Report Summary
INVESTIGATION OF ELEMENTARY REACTION PATHS BY EXPERIMENTS AND THEORETICAL CALCULATIONS
| Project/Area Number |
62470011
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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 |
物理化学一般
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| Research Institution | Hiroshima University |
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Principal Investigator |
SAITO Ko HIROSHIMA UNIV., DEPT. CHEM., ASSOCIATE PROF., 理学部, 助教授 (00033853)
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| Co-Investigator(Kenkyū-buntansha) |
KAKUMOTO Terumitsu HIROSHIMA UNIV., DEPT. CHEM., ASSISTANT, 理学部, 助手 (50185724)
YABUSHITA Satoshi HIROSHIMA UNIV., DEPT. CHEM., ASSISTANT, 理学部, 助手 (50210315)
KANDA Katsuya HIROSHIMA UNIV., DEPT. CHEM., ASSISTANT, 理学部, 助手 (10169790)
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| Project Period (FY) |
1987 – 1989
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| Keywords | REACTION PATH / TRANSITION STATE / REACTION RATE CONSTANT / UNIMOLECULAR REACTION / SHOCK-TUBE METHOD / AB INITIO CALCULATION |
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| Research Abstract |
1. We determined the rate constants of elementary steps of several species at high temperatures. In most cases, the rate constants were in good agreement with the theoretically calculated values. In the case of propynal, however, the experimental decomposition rate was found very high in comparison with the calculation. From the calculated transition-state structure, the high experimental rate constant was explained by the fact that at the saddle point there are excited vibrational modes which give a higher number of state than the equilibrium value.
2. It was found that in the consecutive reaction the secondary step was governed by the structure and the energy of the first transition state. This is one of the methods of chemical activation. The activation by this method gives rise to a special molecular structure depending on the parent molecule. In fact, the carboxylic acids produced from the pyrolysis of esters decomposed via competing paths whose branching ratio was not the same as the values of the thermally equilibrated acids. These phenomena were well explained by ab initio calculations.
3. In the cause of this investigation it was confirmed that the theoretical calculation based on the molecular orbital method well corresponded to the experimental results. This fact is thought to contribute to the field of the chemical kinetics where even now many experimentalists do not believe, the results of the theoretical calculation.
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