Synthesis and structure - Property investigation of polyarenes with conjugated side chains

Abstract

A series of cross-conjugated polyarenes were synthesized and fully characterized. The polymers were soluble in common organic solvents and showed good thermal stability. Powder XRD showed ordered structures for all polymers and significant shift in the emission maxima with increasing concentration, indicating strong aggregation of polymer chains in solution. Solvatochromism studies showed blue shifts of absorption and fluorescence maxima in toluene as compared to the values in THF, suggesting that polymers tend to aggregation less or solvated more in toluene. A large two-photon absorption (TPA) cross section was observed for all polymers due to the unique molecular architectures. Fluorescence lifetime studies revealed that aggregation induced fast decay kinetics. Self-assembled helical nanofibers and nanorings were observed when casted films from polymer solutions. HRTEM and XRD investigation of the thin films revealed nanocrystalline structures of the polymers. © 2008 American Chemical Society.