Molecular Modeling Simulations of the Morphology of Polyphenylene Dendrimers
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- 作者：Patrick Brocorens ; Roberto Lazzaroni ; Jean-Luc Bré ; das
- 刊名：Journal of Physical Chemistry B
- 出版年：2007
- 出版时间：August 9, 2007
- 年：2007
- 卷：111
- 期：31
- 页码：9218 - 9227
- 全文大小：1081K
- 年卷期：v.111,no.31(August 9, 2007)
- ISSN：1520-5207
文摘
Three polyphenylene dendrimers were studied by molecular modeling techniques with the goal of betterdefining the notion of shape persistence often associated with these molecules. We show that despite therigidity of the monomers, a large variety of dendrimer morphologies is accessible, in large part due to theasymmetrical branching pattern of the monomers (they have nodes in meta and para positions with respectto their anchor point). The folding ability of a branch depends on the number and sequence of the meta andpara nodes it contains: while some of the branches are always straight, others can fold back, and the amplitudeof that folding increases with generation. As a result, the range of accessible morphologies increases with thegeneration, from a dense-shell model in low generation to a model intermediate between a dense shell and adense core in high generation. When the typical A2B monomer is replaced by an A4B monomer, the densepacking limit is reached as early as the second generation because of a higher density and the presence ofnodes in the ortho position, which are oriented backward.