Photoresponsive organogels: an amino acid-based dendron functionalized with p-nitrocinnamate

An amino acid-based dendron 1, synthesized and focally functionalized with p-nitrocinnamate, can self-assemble into fibrous network in common organic solvents at low concentration. The most remarkable character of the gel from 1 is photoresponse besides thermo-reversible response. Upon irradiation with UV light at 365 nm, gel to sol transition occurred resulting from the photodimerization of p-nitrocinnamate groups. On the other hand, when the obtained solution was further exposed to short wavelength of UV light at 254 nm, the gel re-formed because of the photocleavage reaction.