Controlling the Supramolecular Polymerization of Donor-Acceptor π-Systems through Hydrogen Bond Intervention

Supramolecular polymerization of donor-acceptor type molecules leads to mixed or self-sorted assemblies depending on the donor-acceptor strength and extent of noncovalent interactions between the components. Herein, we discuss how competing hydrogen bonding motifs control the supramolecular polymerization pathway of a two-component molecular π-system of oligo(p-phenylenevinylene) (OPV-B and OPV-P) donors and perylene bisimide (PBI-B and PBI-A) acceptors. It is shown that among the four different binary combinations (M1-M4) studied, the carboxylic acid/pyridine heterosystem (1 : 2 molar ratio) in M4 favors the coassembled donor-acceptor stacks with a distinct morphology, whose aggregation pathways in toluene/THF (v/v : 9/1) is different from that of the individual components. The nanoscopic molecular arrangement of OPV-P driven by PBI-A in M4 was found to influence the bulk properties such as, morphology, thermomechanical stability and electrical conductivity. For example, the G' and G'' values of M4 is an order of the magnitude higher and exhibited a four-probe electrical conductivity (11.93 Scm^-1 ) higher than that of its individual components. Thus, hydrogen-bond intervention is a powerful strategy to control the supramolecular polymerization of two-component donor-acceptor π-systems.