Molecular dynamics simulations of dendrimer-encapsulated alpha-Keggin ions in trichloromethane solution.
We report on molecular dynamics simulations of dendrimer-encapsulated alpha-Keggin ions in trichloromethane solution. The simulations were done within the NVE ensemble at temperatures around T = 300 K. The eight examined 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 may exhibit enzyme-like regioselectivity and substrate selectivity, e.g., in olefin oxidation. The influence of dendrimer type, dendrimer generation, and number of dendritic cations bound by electrostatic interaction to the polyoxometalate core on the structure and dynamics of the shell has been studied. It is shown that the resulting distribution of trichloromethane molecules within the shell may serve as an indicator for the shell's permeability for small molecules. The dendritic shell causes a size exclusion effect that influences the access of small molecules to the central polyoxometalate ion, i.e., to that part where the enzyme-like reaction of a dendrizyme is supposed to take place.
Brodbeck
Ralf
R
Theoretische Chemie, Fakultät für Chemie, Universität Bielefeld, Postfach 10 01 31, D-33501 Bielefeld, Germany.
Tönsing
Thorsten
T
Andrae
Dirk
D
Volkmer
Dirk
D