5 Morphology transformations in solutions: dynamic supramolecular aggregates

Abstract

J-Aggregates are known to be supramolecular dye assemblies caused by the enthalpically-driven attractive chromophore interaction, being different from micelles or vesicles which are produced by entropy changes in the aqueous phase caused by hydrophobic effects. We succeeded in direct in situ observations and controls of various morphology transformations of “soft” mesoscopic J-aggregates in solution phases for the first time by virtue of their distinctive molecular ordering and prominent optical properties. Characteristic morphologies or structures of the aggregate were clarified in detail. The study on the nanoscopic/mesoscopic morphology of such molecular assemblies will be significant in relation to future supramolecular engineering that aims to obtain different shapes of a compound with differing useful properties.