Comparison Studies on Sub-Nanometer-Sized Ion Clusters in Aqueous Solutions: Vibrational Energy Transfers, MD Simulations, and Neutron Scattering
详细信息 查看全文
- 作者：Yuneng Shen ; Tianmin Wu ; Bo Jiang ; Ganghua Deng ; Jiebo Li ; Hailong Chen ; Xunmin Guo ; Chuanqi Ge ; Yajing Chen ; Jieya Hong ; Xueming Yang ; Kaijun Yuan ; Wei Zhuang ; Junrong Zheng
- 刊名：Journal of Physical Chemistry B
- 出版年：2015
- 出版时间：July 30, 2015
- 年：2015
- 卷：119
- 期：30
- 页码：9893-9904
- 全文大小：554K
- ISSN：1520-5207
文摘
In this work, MD simulations with two different force fields, vibrational energy relaxation and resonant energy transfer experiments, and neutron scattering data are used to investigate ion pairing and clustering in a series of GdmSCN aqueous solutions. The MD simulations reproduce the major features of neutron scattering experimental data very well. Although no information about ion pairing or clustering can be obtained from the neutron scattering data, MD calculations clearly demonstrate that substantial amounts of ion pairs and small ion clusters (subnanometers to a few nanometers) do exist in the solutions of concentrations 0.5 M*, 3 M*, and 5 M* (M* denotes mole of GdmSCN per 55.55 mole of water). Vibrational relaxation experiments suggest that significant amounts of ion pairs form in the solutions. Experiments measuring the resonant energy transfers among the thiocyanate anions in the solutions suggest that the ions form clusters and in the clusters the average anion distance is 5.6 脜 (5.4 脜) in the 3 M* (5 M*) Gdm鈥揇SCN/D2O solution.