Perylene diimide functionalized polynorbornene: a macromolecular scaffold for supramolecular self-assembly

We have synthesized and characterized a polymer comprising a polynorbornene backbone with perylene diimide (PDI) pendant groups. The polymer exhibits intramolecular self-assembly into molecular aggregates that can be controlled via solvent quality. In a medium that solvates the polymer backbone well the PDI chromophores self-assemble into characteristic H-type aggregates aligned along the polymer backbone. In contrast, in a solvent medium that does not solvate the polymer well the polynorbornene backbone collapses into a globular conformation preventing the aggregation of the PDI chromophores, which display monomer-like photophysics. The polymer photophysics are recorded under a variety of conditions, including lifetimes and relative quantum yields. Furthermore, we utilize the weakly coupled H-aggregate model to quantify the exciton bandwidth of the polymer structure and demonstrate that polymer thin films can retain the same chromophore aggregated morphology as the fully solvated polymer.