The Effect of Macromolecular Architecture in Nanomaterials: A Comparison of Site Isolation in Porphyrin Core Dendrimers and Their Isomeric Linear Analogues

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• 作者：Eva M. Harth ; Stefan Hecht ; Brett Helms ; Eva E. Malmstrom ; Jean M. J. Fré ; chet ; and Craig J. Hawker
• 刊名：Journal of the American Chemical Society
• 出版年：2002
• 出版时间：April 17, 2002
• 年：2002
• 卷：124
• 期：15
• 页码：3926 - 3938
• 全文大小：352K
• 年卷期：v.124,no.15(April 17, 2002)
• ISSN：1520-5126

文摘

The influence of macromolecular architecture on the physical properties of polymeric materialshas been studied by comparing poly(benzyl ether) dendrons with their exact linear analogues. The resultsclearly confirm the anticipation that dendrimers are unique when compared to other architectures. Physicalproperties, from hydrodynamic volume to crystallinity, were shown to be different, and in a comparativestudy of core encapsulation in macromolecules of different architecture, energy transduction from the polymerbackbone to a porphyrin core was shown to be different for dendrimers as compared to that of isomericfour- or eight-arm star polymers. Fluorescence excitation revealed strong, morphology dependentintramolecular energy transfer in the three macromolecular isomers investigated. Even at high generations,the dendrimers exhibited the most efficient energy transfer, thereby indicating that the dendritic architectureaffords superior site isolation to the central porphyrin it surrounds.