Trajectory analysis of a kinetic theory for isomerization dynamics in condensed phases
Trajectory analysis of a kinetic theory for isomerization dynamics in condensed phases
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凝聚相异构化动力学动力学理论的轨迹分析
DOI：
10.1063/1.438028
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发表时间：
1979
影响因子：
4.4
通讯作者：
B. Berne
中科院分区：
文献类型：
--
作者：
J. Montgomery;D. Chandler;B. Berne
我们使用一个精确的微观形式主义，研究在液体中的异构化动力学的随机模型的影响。在该模型中，反应坐标在多稳态势中移动，并通过以指定的平均碰撞频率发生的随机碰撞耦合到热浴。数值求解了该系统的非线性动力学。研究发现，如果反应的活化能足够高，则通常的异构化线性速率定律对任何非零碰撞频率都是有效的。这种行为的原因进行了详细讨论。通过适当的参数选择，我们可以得出关于正丁烷在液体中的trans-gauche异构化的结论。过渡态理论被发现高估的速率常数至少2至3倍，在任何碰撞频率。计算了碰撞对激活体积的贡献。在1个大气压下，结果比过渡态理论活化体积大一个数量级。
We use an exact microscopic formalism to study the implications of a stochastic model of isomerization dynamics in liquids. In the model, a reaction coordinate moves in a multistable potential and is coupled to a thermal bath via random collisions which occur with a specified average collision frequency. The nonlinear dynamics for this system is solved numerically. It is found that the usual linear rate law for isomerization is valid for any nonzero collision frequency if the activation barrier to reaction is sufficiently high. The reasons for this behavior are discussed at length. With appropriate parameter choices, we can draw conclusions concerning the trans–gauche isomerization of n‐butane in liquids. Transition state theory is found to overestimate the rate constant by at least a factor of 2 to 3 at any collision frequency. The collisional contribution to the volume of activation is calculated. At 1 atm, the result is an order of magnitude larger in size than the transition state theory activation vo...