Amphiphilic Perylene-Calixarene Hybrids: Synthesis and Tunable Self-Assembly
F. Rodler, B. Schade, C. M. Jäger, S. Backes, F. Hampel, C. Böttcher, T. Clark, and A. Hirsch – 2015
The first highly water-soluble perylene-calixarene 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 pi-pi 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.