various organic solvents. In contrast, cis-3a shows a poor gelationability or none at all, owing to its good solubility. Considering the difference in gelation abilities of the compounds trans-3a and cis-3a and the photo-responsive conformational changes of the stilbene part of the molecule, a controlled gelation by light was achieved. FT-IR and 1H NMR spectroscopic measurements support the view that hydrogen