Gerd Gröger
(graduate student)

phone: 5395
room: 105
email: groeger@chemie.uni-wuerzburg.de

SUPRAMOLECULAR POLYMERS: ADVANCED SMART MATERIALS BASED ON METAL-LIGAND AND IONIC INTERACTION

Supramolecular Polymers belong to the most promising class of new materials for tomorrow. These materials respond to a change in temperature, solvent or the presence of a chemical signal.

With this motivation we synthesized bifunctional molecules with two orthogonal self-complementary binding sites based on either metal-ligand and or ionic interactions. On the one hand we use a guanidiniocarbonyl pyrrole carboxylate zwitterion. Its ion pair driven self-association to form dimers even in water makes it one of the most stable self-assembling systems known so far (K = 170 M^-1 in water).[1] This zwitterion is coupled with metal complexing ligands such as terpyridines, bipyridines and catechols, which form complexes with metal ions like tin, iron, osmium or ruthenium.

Hence, by ionic or metal ligand interactions alone these hybrid molecules can only form dimers. But if both “chemical signals” (correct pH range and the metal ion) are present at the same time linear and 2D dimensional supramolecular polymer can form. The syntheses and the self-assembling properties of such compounds as investigated by NMR-dilution, UV- and fluorescence studies will be described.

[1] Schmuck C., Wienand W, J. Am. Chem. Soc.2003, 125, 452-459.