Amphiphilic Perylene–Calix[4]arene Hybrids: Synthesis and Tunable Self-Assembly

The first highly water-soluble perylene–calix[4]­arene
hybrid
with the calixarene scaffold acting as a structure-determining central
platform is presented. In this tetrahedrally shaped amphiphilic architecture
the hydrophilic and hydrophobic subunits are oriented at the opposite
side of the calixarene platform. The hydrophobic part contains the
two perylene diimide moieties, which enable strong π–π
interactions in self-assembly processes. Two hydrophilic Newkome-type
dendrons provide sufficient water solubility at slightly basic conditions.
The tetrahedrally shaped amphiphile displays an unprecedented aggregation
behavior down to concentrations as low as 10–7 mol
L–1. The intriguing self-assembly process of the
compound in water as well as under changed polarity conditions, achieved
by addition of THF, could be monitored by the complemented use of
cryogenic transmission electron microscopy (cryo-TEM), UV–vis
spectroscopy, and fluorescence spectroscopy. Molecular-dynamics and
molecular modeling simulations helped in understanding the interplay
of supramolecular and optical behavior.

本研究报道了首例以杯芳烃骨架作为结构导向中心平台的高水溶性苝-杯[4]芳烃（perylene–calix[4]arene）杂化材料。在该四面体构型的两亲性组装体中，亲水与疏水亚基分别排布于杯芳烃平台的相对两侧。其疏水部分包含两个苝二酰亚胺（perylene diimide）基团，该基团可在自组装过程中形成强π-π相互作用。两个亲水性纽科姆型树枝状基团（Newkome-type dendrons）可在弱碱性条件下赋予该杂化材料足够的水溶性。这种四面体构型两亲分子展现出前所未有的聚集行为，可在低至10⁻⁷ mol·L⁻¹的极低浓度下发生聚集。该化合物在水中以及通过添加四氢呋喃（THF）改变溶剂极性条件下的独特自组装过程，可通过结合使用低温透射电子显微镜（cryo-TEM）、紫外-可见光谱（UV–vis spectroscopy）与荧光光谱进行监测。分子动力学（molecular dynamics）与分子建模模拟有助于阐明超分子行为与光学行为之间的相互作用。