On the Mechanism of Reversible Unimolecular Reactions and the Canonical (“High Pressure”) Limit of the Rate Coefficient at Low Pressures*)
On the Mechanism of Reversible Unimolecular Reactions and the Canonical (“High Pressure”) Limit of the Rate Coefficient at Low Pressures*)
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关于可逆单分子反应的机理和低压速率系数的规范（“高压”）极限*)
DOI：
10.1002/bbpc.19840880204
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发表时间：
1984
期刊：
影响因子：
--
通讯作者：
M. Quack
中科院分区：
文献类型：
--
作者：
M. Quack
Jost [1]对广义一级动力学的处理用于可逆单分子反应机理的新讨论。详细分析了时间依赖的平均微观速率系数和水平人口的异构化反应的一个现实的模型，使用精确解。它表明，单分子脱落的宏观弛豫主要是由于人口减少的反应水平所建议的不可逆林德曼机制，而是由于快速的逆反应，即使在早期。它进一步表明，平均微观速率系数可以直接测量，在原则上。在平衡时，它们等于速率系数的正则（“高压”）极限，即使对于任意低的压力。提出了无需外推即可获得高压极限速率系数的实用实验方案。
Jost's [1] treatment of generalized first order kinetics is used for a new discussion of the mechanism of reversible unimolecular reactions. A detailed analysis of time dependent average microscopic rate coefficients and level populations is presented using exact solutions for a realistic model of an isomerization reaction. It is shown that unimolecular fall-off for the macroscopic relaxation is not mainly due to a reduced population of reactive levels as suggested by the irreversible Lindemann mechanism, but rather due to a fast reverse reaction even at early times. It is furthermore shown that the average microscopic rate coefficients can be measured directly, in principle. At equilibrium they are equal to the canonical (“high pressure”) limit of the rate coefficient even for arbitrarily low pressures. Practical experimental schemes are suggested for thus obtaining high pressure limiting rate coefficients without extrapolation procedures.