THE CHEMICAL-REACTION MOLECULAR-DYNAMICS METHOD AND THE DYNAMIC TRANSITION-STATE - PROTON-TRANSFER REACTION IN THE FORMAMIDINE AND WATER SOLVENT SYSTEM
THE CHEMICAL-REACTION MOLECULAR-DYNAMICS METHOD AND THE DYNAMIC TRANSITION-STATE - PROTON-TRANSFER REACTION IN THE FORMAMIDINE AND WATER SOLVENT SYSTEM
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DOI：
10.1021/ja00003a007
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发表时间：
1991-01-30
影响因子：
15
通讯作者：
YAMABE, T
中科院分区：
文献类型：
--
作者：
NAGAOKA, M;OKUNO, Y;YAMABE, T
采用化学反应分子动力学（CRMD）方法分析了溶液中的化学反应机理，将溶质分子和少量溶剂分子视为一个超分子，在溶质分子内势能面上对化学反应动力学进行了含时分析.我们考察了一个质子转移反应，即甲脒-水体系，在考虑了静态的“电子”溶剂效应后，着重研究了化学反应中的动力学效应。采用了恒温方案（CTS）和恒能方案（CES），通过氢键关联函数（HBCF）中出现的尖点，发现了一种新的临界态--动态过渡态。尖点是由于O-H键长的变化停止，这在产物区域产生了水分子。在CES中，出现了交替调制振荡，这是三原子系统的一个特征，应该在溶液中的能量流动中起重要作用。强调了化学反应动力学研究应在相空间中考虑动能或动量。
The chemical reaction mechanism in solution is analyzed by using the chemical reaction molecular dynamics (CRMD) method where a solute molecule and a few solvent molecules are regarded as a supermolecule and the chemical reaction dynamics can be analyzed in a time-dependent way on the intrasupermolecular potential surface. We have examined a proton transfer reaction, the formamidine-water system, and focused on the dynamic effect in the chemical reaction after considering the static "electronic" solvent effect. Two schemes, the constant-temperature scheme (CTS) and the constant-energy scheme (CES), have been employed, and a new type of critical state, named the dynamic transition state (DTS), was found by the appearance of a cusp in the hydrogen-bonding correlation function (HBCF). The cusp is due to the stopping of change in the O-H bond length, which produces a water molecule in the product region. In the CES, alternately modulated oscillation appeared, which is a characteristic in triatomic systems and should play an important role in energy flow in solution. It is emphasized that chemical reaction dynamics should be studied in the phase space by taking the kinetic energy or momentum into consideration.