Synthesis and properties of metallo-supramolecular poly(p-phenylene ethynylene)s

The use of metal-ligand binding as the driving force for the self-assembly polymerizations of a ditopic monomer offers a facile route to the preparation of metallo-supramolecular polymers. We report, herein, the utilization of this approach for the polymerization of a conjugated macromonomer that was derived by functionalizing a low-molecular-weight poly(2,5-dialkoxy-p-phenylene ethynylene) core with 2,6-bis(1′-methylbenzimidazolyl)pyridine (Mebip) ligands on the two terminal positions. The supramolecular polymerization of this macromonomer with equimolar amounts of Zn ²⁺ or Fe ²⁺ resulted in polymers, which exhibit appreciable mechanical strength, but due to their self-assembly ability offer the ease of processing of low-molecular-weight compounds. The optical and thermomechanical properties of the new materials were investigated by a variety of analytical techniques, including ultraviolet-visible and photoluminescence spectroscopy, dynamic mechanical thermoanalysis, and thermogravimetric analysis.