Full description of the orientational statistics of molecules near to interfaces.: Water at the interface with CCl4
Full description of the orientational statistics of molecules near to interfaces.: Water at the interface with CCl4
复制标题
DOI：
10.1039/b313231p
复制
发表时间：
2004-04-21
影响因子：
3.3
通讯作者：
Horvai, G
中科院分区：
文献类型：
--
作者：
Jedlovszky, P;Vincze, A;Horvai, G
在Monte Carlo计算机模拟的基础上，对水/CCl4液-液界面附近水分子的取向统计进行了不同层次的统计分析。确定了各种分子固定向量相对于界面沿界面法向轴的平均取向曲线，描述这些取向的参数的单变量分布，以及两个独立取向参数在不同水层中的二元联合概率分布。结果表明，只有两个独立的取向参数的二元联合概率分布才能完整地描述整个水分子的取向偏好。发现了水分子的两种共存的优先取向：在第一种取向中，存在于整个界面区域，水分子位于与界面平行的平面上；而在第二种优先取向中，只存在于渗透到非极性相深处的水分子中，水分子的平面垂直于界面，其O-H键的一个直接指向非极性相。后一种取向对应于与界面平行的水分子的非极性相的氢键邻居的取向。
The orientational statistics of water molecules at the vicinity of the water/CCl4 liquid-liquid interface is analyzed at different levels of statistics on the basis of a Monte Carlo computer simulation. Profiles describing the average orientation of various molecule-fixed vectors relative to the interface along the interface normal axis, monovariate distributions of parameters describing these orientations, as well as the bivariate joint probability distribution of two independent orientational parameters in different water layers are determined. It is demonstrated that a complete description of the orientational preferences of the entire water molecule can only be given by the bivariate joint probability distribution of two independent orientational parameters. Two co-existing preferred orientations of the water molecules have found: in the first orientation, present at the entire interfacial region, the water molecule lays in a plane parallel with the interface, whereas in the second preferred orientation, present only among the water molecules penetrated deepest into the nonpolar phase, the plane of the water molecule is perpendicular to the interface and one of its O-H bonds points straight toward the nonpolar phase. This latter orientation corresponds to the orientation expected for a hydrogen bonded neighbor, located toward the nonpolar phase, of a water molecule which lays parallel with the interface.