Dipole-Moment-Driven Cooperative Supramolecular Polymerization

While the mechanism of self-assembly of a-conjugated molecules has been well studied to gain control over the structure and functionality of supramolecular polymers; the intermolecular interactions underpinning it are poorly understood. Here, we study the mechanism of self-assembly of perylene bisimide derivatives possessing dipolar carbonate groups as linkers. It was observed that the combination of carbonate linkers and cholesterol/dihydrocholesterol self-assembling Moieties led to a cooperative mechanism of self-assembly. Atomistic molecular dynamics Simulations of an assembly in explicit solvent strongly Suggest that the dipole dipole interaction between the carbonate groups imparts a macro-dipolar character to the assembly. This is confirmed experimentally through the observation of a significant polarization in the bulk phase for molecules following a cooperative mechanism. The cooperativity is attributed to the presence of dipole dipole interaction in the assembly. Thus, anisotropic long-range intermolecular interactions such as dipole dipole interaction can Serve as a way to obtain cooperative self-assembly and aid in rationalizing and predicting the mechanisms in various synthetic supramolecular polymers: