Self-Assembling Molecular Trees Containing Octa-p-phenylene: From Nanocrystals to Nanocapsules

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• 作者：Yong-Sik Yoo ; Jin-Ho Choi ; Ji-Ho Song ; Nam-Keun Oh ; Wang-Cheol Zin ; Soojin Park ; Taihyun Chang ; and Myongsoo Lee
• 刊名：Journal of the American Chemical Society
• 出版年：2004
• 出版时间：May 26, 2004
• 年：2004
• 卷：126
• 期：20
• 页码：6294 - 6300
• 全文大小：367K
• 年卷期：v.126,no.20(May 26, 2004)
• ISSN：1520-5126

文摘

Tree-shaped molecules consisting of octa-p-phenylene as a stem segment and oligoetherdendrons as a flexible head were synthesized and characterized. The molecular tree based on a smallflexible head self-assembles into a lamellar structure, whereas the molecule based on a larger headgroupself-assembles into a discrete heptameric bundle that organizes into a 3-D primitive orthorhombicsupercrystals, as confirmed by X-ray scatterings and transmission electron microscopic (TEM) observations.Optical studies revealed that the absorption and emission maxima and absorption edge of the 3-D structureshift to higher energy compared to those of the lamellar structure. The molecules in dilute solution (THF/water = 1:10 v/v) were observed to self-assemble into capsule-like hollow aggregates, as confirmed bydynamic and static light scatterings, scanning electron microscopy (SEM), and TEM investigations. Theseresults demonstrate that tree-shaped molecules are capable of packing into organized discrete nanocrystalswith parallel arrangement as well as hollow nanocapsules with radial arrangement, depending on thepresence of selective solvents for flexible headgroup.