Abstract:
Ostwald ripening allows the synthesis of 1D
nanorods of metal and semiconductor nanoparticles.However, this phenomenon is unsuccessful with organic π-systems due to their spontaneous self-assembly to elongated fibers or tapes. Here we demonstrate the uses
of light as a versatile tool to control the ripening of amorphous organic nanodots (ca. 15 nm) of an azobenzene-derived molecular assembly to micrometersized supramolecular rods. A surface-confined dipole
variation associated with a low-yield (13−14%) trans−cis
isomerization of the azobenzene moiety and the
consequent dipole−dipole interaction in a nonpolar
solvent is believed to be the driving force for the ripening
of the nanodots to rods
