Supramolecular branching and cross-linking of terpyridine-modified copolymers : complexation and decomplexation studies in diluted solution

A series of poly(methyl methacrylate) copolymers with terpyridine units in the side chains was obtained by free radical polymerization. The free terpyridine units were complexed by iron(II) and zinc(II) ions, and the complexation behavior was studied in detail, utilizing UV-vis and viscosity titration experiments. Complexation of the polymer chains could be observed, which resulted in characteristic UV-vis absorption bands and an increase in the solution viscosity. Addition of a strong competitive ligand (hydroxyethyl ethylenediaminetriacetic acid, HEEDTA) resulted in an efficient decomplexation.