Synthesis and Self‐assembly of Benzoperylene Benzimidazoles: Tunable Morphology with Aggregation‐Induced Enhanced Emission

Abstract Benzoperylene benzimidazoles ( BPBIs ) based π‐systems were synthesized and their self‐assembly in both non‐polar and polar solvents investigated. Due to the presence of donor and acceptor functional groups, BPBIs absorb light up to 600 nm and display red fluorescence (575–800 nm). Depending on the solvent and side chain, BPBIs self‐assemble into various nanostructures such as nanoribbons, nanorods, nanofibers and nanoparticles. Notably, these ordered nanostructures are formed by BPBIs in both polar and non‐polar solvents without the aid of hydrogen bonding and amphiphilic interactions due to the presence of a large rigid π‐system. Interestingly, BPBIs follow a weakly cooperative mechanism during the self‐assembly. Moreover, BPBIs show aggregation‐induced enhanced emission (AIEE) in all the self‐assembled nanostructures which is not common for rigid π‐systems.