Interaction of OH- with Xylan and Its Hydrated Complexes: Structures and Molecular Dynamics Study Using Elongation Method
Interaction of OH- with Xylan and Its Hydrated Complexes: Structures and Molecular Dynamics Study Using Elongation Method
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OH- 与木聚糖及其水合复合物的相互作用：使用伸长法研究结构和分子动力学
DOI：
10.1007/s00894-015-2666-5
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
and Yuriko Aoki
中科院分区：
文献类型：
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作者：
Lin Jin;Kai Liu;and Yuriko Aoki
采用延伸优化（ELG-OPT）方法和延伸从头算分子动力学模拟（ELG-MD）方法对羟基与木聚糖12及其水合复合物的相互作用进行了理论研究. OH−基团可以从末端木聚糖环上夺取一个H原子，形成复合物（木聚糖）12−-H2O，没有任何能垒。一个和两个额外的水分子也被添加到相同的末端木聚糖环上。将ELG-OPT方法得到的所有几何优化结果与传统的计算结果进行了比较，结果表明ELG-OPT方法对（xylan）12、（xylan）12-OH-及其水合复合物的几何优化效果较好。此外，在300 K、500 K和700 K下对复合物（木聚糖）12−-H2O、（木聚糖）12−-2H2O和（木聚糖）12−-3H2O进行了10 ps从头算分子动力学模拟。（木聚糖）12−-H2O复合物在室温下稳定。而由OH−基团形成的H2O分子在500 K时可以运动。在700 K时，H-抽象反应逆转。加入额外的水分子只会加速水转移反应，但不会发生更多的化学反应，并且随着温度的升高，转移时间缩短。即使在高温下加入两个额外的水分子，复合物（木聚糖）12−-H2O也变得非常稳定，这表明两个额外的水分子稳定了复合物（木聚糖）12−-H2O。
The interaction of OH−group with (xylan)12and its hydrated complexes were theoretically studied using elongation optimization (ELG-OPT) method and elongation ab initio molecular dynamics simulation (ELG-MD) method. OH−group could abstract a H-atom from the terminal xylan ring to form a complex (xylan)12−–H2O without any energy barrier. One and two extra water molecules were also added to the same terminal xylan ring. All the geometry optimization results obtained using elongation method were compared with conventional calculation results, and it suggested that ELG-OPT method worked well for (xylan)12, (xylan)12–OH−, and its hydrated complexes. Moreover 10 ps ab initio molecular dynamics simulations were performed for complexes (xylan)12−–H2O, (xylan)12−–2H2O, and (xylan)12−–3H2O at 300 K, 500 K, and 700 K. (xylan)12−–H2O complex was stable at room temperature. However H2O molecule which was formed by OH−group could move at 500 K. At 700 K the H-abstract reaction reversed. Adding an extra water molecule only accelerated the water transfer reaction, but no more chemical reactions occurred, and the transfer time decreased when the temperature increased. The complex (xylan)12−–H2O became very stable when adding two extra water molecules even at high temperature, and it indicated that two extra water molecules stabilized the complex (xylan)12−–H2O.