Stiff-Stilbene-Bridged Biscalix[4]arene as a Highly Light-Responsive Supramolecular Gelator.

A newly designed stiff-stilbene functionalized biscalix[4]arene in its form - could be near-quantitatively photoswitched to the -isomer - under irradiation of 385 nm UV light. The -biscalix[4]arene - was found to be a supergelator in nonpolar organic solvents, e.g., cyclohexane, hexane, pentane, and ether, with critical gelation concentrations as low as 0.2, 0.5, 0.5, and 0.4% w/v, respectively. The - configurational isomerism of biscalix[4]arene resulted in distinct self-assembly modes, leading to interesting microscopic morphological changes from honeycomb and ringlike structures to rodlike dense fibrous networks.