Electrostatics for exploring the nature of the hydrogen bonding in polyethylene oxide hydration
Electrostatics for exploring the nature of the hydrogen bonding in polyethylene oxide hydration
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DOI：
10.1021/jp036921o
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发表时间：
2004-02-19
影响因子：
3.3
通讯作者：
Weitz, DA
中科院分区：
文献类型：
--
作者：
Aray, Y;Manuel, M;Weitz, DA
用静电势的拓扑特征和标准密度泛函理论方法研究了聚环氧乙烷（CH_2-CH_2-O）（n）（n = 2-40）模型与水的结合.结果发现，在一般情况下，周围的氧原子的最小值的轮廓重叠形成一个负值的螺旋盘绕在一个正值的螺旋。正区定义了O-C-C-O单元中的螺旋槽，最小孤对临界点位于该螺旋槽中。水分子的拓扑分析也表明，正的水O-H区和负的PEO孤对之间的吸引静电效应在PEO-水体系的氢键中起着重要的作用。因此，V（r）拓扑预测了PEO链周围的水分子线圈与醚氧的两个位点形成氢键。该线圈以这样的方式形成，即更多的水分子聚集在围绕聚（环氧乙烷）的氧原子的空腔上，其中负区的最小值位于该空腔上。
Binding between water and models of poly(ethylene oxide), (CH2-CH2-O)(n), n = 2-40, has been studied using the topographic features of the electrostatic potential, V(r), and standard density functional theory methods. It was found that, in general, the contour around the minima of the oxygen atoms overlap forming a negative-valued spiral coiled around a positive-valued helix. The positive zone defines a helical groove in the O-C-C-O units where minima lone pairs critical points are located. Topological analysis of the water molecule has also suggested that the attractive electrostatic effect between the positive water O-H zone and the negative PEO lone pairs plays an important role in the hydrogen bonding of the PEO-water system. Thus, the V(r) topology predicts a coil of water molecules around the PEO chain forming hydrogen bonding with two sites of ether oxygens. This coil is formed in such a way that more water molecules accumulate on the cavities surrounding the poly(ethylene oxide)'s oxygen atoms where the minima of the negative zone are located.