Molecular Dynamics Simulations of Dendrimer-Encapsulated -Keggin Ions in Trichloromethane Solution

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• 作者：Ralf Brodbeck ; Thorsten Tö ; nsing ; Dirk Andrae ; Dirk Volkmer
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：April 24, 2008
• 年：2008
• 卷：112
• 期：16
• 页码：5153 - 5162
• 全文大小：802K
• 年卷期：v.112,no.16(April 24, 2008)
• ISSN：1520-5207

文摘

We report on molecular dynamics simulations of dendrimer-encapsulated -Keggin ions in trichloromethanesolution. The simulations were done within the NVE ensemble at temperatures around T = 300 K. The eightexamined systems are model compounds for dendrizymes, a hybrid material where a polyoxometalate ion(the core) is surrounded by amphiphilic cationic dendrimers (the shell) such that the complete system mayexhibit enzyme-like regioselectivity and substrate selectivity, e.g., in olefin oxidation. The influence ofdendrimer type, dendrimer generation, and number of dendritic cations bound by electrostatic interaction tothe polyoxometalate core on the structure and dynamics of the shell has been studied. It is shown that theresulting distribution of trichloromethane molecules within the shell may serve as an indicator for the shell'spermeability for small molecules. The dendritic shell causes a size exclusion effect that influences the accessof small molecules to the central polyoxometalate ion, i.e., to that part where the enzyme-like reaction of adendrizyme is supposed to take place.