(262b) Side-Chain Metallo-Supramolecular Polymers: Synthesis and Characterization

Metallo-supramolecular polymers represent an important class of self-assembled materials.  The metal-ligand bond is highly directional and specific and the strength of the interaction can be easily tuned by changing the metal or manipulating the ligand structure.  These properties offer the possibility to readily prepare materials whose macroscopic properties can be easily modified for a particular property or application.  To this end, we have initiated a program to incorporate non-covalent metallo-supramolecular bonds into polymer systems in an effort to prepare materials with enhanced, highly tunable properties.  Initial studies focus on a model system consisting of a poly(n-butyl acrylate) copolymer with 2,6-bis-(1’ methyl benzimidazoyl) pyridine tethered along the backbone.  Addition of metal ions cross-links the polymer forming a network structure.  The kinetics and thermodynamics of the self-assembly process of the ligand with various metal ions was studied with UV/Vis, ¹H NMR, and capillary viscometry.  The impact of changing the metal-ligand combination on material properties was investigated with dynamic mechanical analysis.  Furthermore, the metal-ligand interaction was directly probed via atomic force spectroscopy based single molecule force spectroscopy and compared with computationally derived force data.