Department of Chemistry and Biochemistry, University of California, San Diego, 9500 Gilman Drive, La Jolla, California 92093, USA.
J Chem Phys. 2012 Aug 7;137(5):054704. doi: 10.1063/1.4739254.
The effects of electronic polarization on the adsorption of water in the MIL-53(Cr) metal-organic framework are investigated using molecular dynamics simulations. For this purpose a fully polarizable force field for MIL-53(Cr) was developed which is compatible with the ab initio-based TTM3-F water model. The analysis of the spatial distributions of the water molecules within the MIL-53(Cr) nanopores calculated as a function of loading indicates that polarization effects play an important role in the formation of hydrogen bonds between the water molecules and the hydroxyl groups of the framework. As a result, large qualitative differences are found between the radial distribution functions calculated with non-polarizable and polarizable force fields. The present analysis suggests that polarization effects can significantly impact molecular adsorption in metal-organic frameworks under hydrated conditions.
利用分子动力学模拟研究了电子极化对 MIL-53(Cr) 金属有机骨架中水分子吸附的影响。为此，开发了一种完全极化的 MIL-53(Cr) 力场，该力场与基于 ab initio 的 TTM3-F 水模型兼容。作为负载函数计算的 MIL-53(Cr) 纳米孔内水分子的空间分布分析表明，极化效应在水分子与骨架的羟基之间形成氢键中起着重要作用。因此，在使用非极化和极化力场计算的径向分布函数之间发现了很大的定性差异。目前的分析表明，在水合条件下，极化效应对金属有机骨架中的分子吸附有显著影响。
