物理化学学报2018，Vol.34Issue(5)：483-491,9.DOI:10.3866/PKU.WHXB201709111
RbCl和CsCl水溶液结构的X射线散射及经验势结构精修模拟
Structure of Aqueous RbCl and CsCl Solutions Using X-Ray Scattering and Empirical Potential Structure Refinement Modelling
摘要
Abstract
X-ray scattering measurements were performed on 1.0 mol·dm-3 RbCl and CsCl aqueous solutions.The X-ray structure factors were subjected to empirical potential structure refinement to extract detailed structural information on hydrated Cl-,Rb+,Cs+,and ion association,as well as bulk water,in terms of the individual site-site pair correlation functions,coordination number distributions,and spatial density functions (three-dimensional structure).Cl-is found to have a relatively stable six-fold coordination of water molecules with a Cl--H2O distance of 0.321 nm,and without a significant cation effect on its local structure.Rb+ is surrounded on an average by 7.3 + 1.4 water molecules with a Rb+-H2O distance of 0.297 nm,whereas 8.4 + 1.6 water molecules hydrate Cs+ at a Cs+-H2O distance of 0.312 nm.It is likely that Rb+ has a stronger hydration shell than Cs+,as evidenced by the presence of the second hydration shell of the former.Contact ion-pairs are partially formed in both solutions and characterized by the Rb+-Cl-and Cs+-Cl-distances of 0.324 nm and 0.336 nm.The solvent-separated ion pairs for both ions are discemible at around 0.6 nm.Rb+ has a stronger electrostatic interaction and hence a relatively stronger ion association with Cl-than Cs+.关键词
RbCl/CsCl/溶液结构/X射线散射/EPSRKey words
RbCl/CsCl/Solution structure/X-ray scattering/EPSR分类
化学化工引用本文复制引用
周永全,曾我良枝,山口敏男,房艳,房春晖..RbCl和CsCl水溶液结构的X射线散射及经验势结构精修模拟[J].物理化学学报,2018,34(5):483-491,9.基金项目
The project was supported by the Natural Science Foundation of Qinghai Province,China (2015-ZJ-945Q) and Youth Innovation Promotion Association,CAS,China (2017467).青海省自然科学基金(2015-ZJ-945Q)和中国科学院青年创新促进会((2017467)资助项目 （2015-ZJ-945Q）
