Controlled aggregation of -conjugated systems offers interesting electronic and photonic functional materials that are different from their monomeric state. The self-association of chromophores in the solid is a frequently encountered phenomenon in dye chemistry owing to strong intermolecular Van der Waals-like attractive forces between molecules. The aggregates in the solid state exhibit distinct changes in the absorption band as compared to the monomeric species. Thus, the aggregation pattern of -conjugated oligomers will determine the device performance and/or goal i.e. OLED or solar cells. In other words, it should be possible using the same electro-active molecule to tune its optoelectronic properties by simply playing on the modulation of its aggregation. However, the rational control of a dye aggregation is still difficult because molecules tend to spontaneously align themselves into a one-dimensional infinite aggregate in a face-to-face manner by means of -stacking and/or Van der Waals interactions. The development of a method to control their aggregation behavior and orientations is a challenge.

In this context, we developed a new family of oligo-phenylenevinylene derivatives incorporating a conjugated phthalic imide phenylene vinylene (ImPV) substructure. The imide functions are thermally and chemically stable. Their electron affinity confers to the whole molecule the electron injection properties that are lacking to the phenylenevinylene moiety. Modifications of their aggregation state could be envisaged via the imide function. Indeed, any amine could be condensed to the phthalic anhydride.

In this presentation, we will illustrate our strategy to progress in the control of their supramolecular organization in order to control their opto-electronic properties in devices.