Photophysical and self-assembly properties of asymmetrical multi-aralkyl and arylaldehyde substituted pyrene derivatives

A series of novel asymmetrical pyrene derivatives with aralkyl and aldehyde groups have been successfully synthesized, and their spectroscopic parameters were investigated detailedly. The effects of aralkyl substituent amounts on the electronic absorption and emission spectra have been explored in evaluation of their potential as optical materials components. Moreover, the electrochemical properties of the new pyrene derivatives have been studied for the molecules' HOMO and LUMO levels by cyclic voltammograms. In particular, titration of anhydrous ethanol into dilute CH₂Cl₂ solution of above compounds, an unusual change of the fluorescence value was observed. The change is believed to correlate strongly to intermolecular charge transfer. The morphological evolution of self-assembled pyrene derivatives with (arylethynyl)aldehyde substituents, from tamen-distinct-like morphologies to vesicular textures, was obtained by increasing aralkyl-substituted fragments. These asymmetrical discotic compounds represent an interesting set of candidates for optoelectronic device components.