Selective Metal-Complexation on Polymeric Templates and Their Investigation via Isothermal Titration Calorimetry

Selective complexation of metal ions represents a powerful tool for the development of versatile supramolecular architectures. While research in the field of molecular devices and machinery is sophisticated, the selective formation of metal complexes is not prevalent in polymer chemistry. Thus, the implementation of orthogonal binding concepts into a polymeric matrix is presented. In this context, an end-functionalized poly(N-isopropylacrylamide) (PNIPAm) carrying zinc-porphyrin (ZnTPP) as well as a terpyridine (tpy) ligand side by side is utilized. With these binding sites, the polymer can simultaneously interact with a pyridine moiety via a ZnTPP interaction and a terpyridine unit by the formation of a bis-terpyridine complex. The complexation behavior of this polymer and different model compounds is intensively investigated by isothermal titration calorimetry. The obtained results indicate that the reported orthogonality of these two systems is successfully transferred into a functional polymeric architecture.

Automated summary

The selective complexation of metal ions plays a key role in developing versatile supramolecular architectures, and the incorporation of orthogonal binding concepts into polymeric matrices has been investigated. By utilizing end-functionalized poly(N-isopropylacrylamide) carrying zinc-porphyrin and a terpyridine ligand, the polymer can simultaneously interact with different ligands, showcasing successful transfer of orthogonality into functional polymeric architecture.