Ligand substitution reactions inside a copper containing polymer

CHED 1187

Dalton S. Nagasako, naga9208@pacificu.edu and Joel W. Gohdes, gohdes_J@pacificu.edu. Department of Chemistry, Pacific University, 2043 College Way, Forest Grove, OR 97116
A molecular imprint polymer (MIP) was synthesized via a standard method using a zinc complex of a bis-imidazole ligand as a template. After removal of the metal and auxiliary ligands, the synthesized MIP was subject to various tests to characterize its properties. The binding of Cu2+ and Zn2+ were studied at pH 7 using ICP-AES. The results were fit to Fruendlich and Langmuir-Fruendlich isotherms to yield apparent binding constants of 7000. The ligand substitution at the Cu2+ substituted polymer was studied via UV-vis spectroscopy to determine whether or not the active site of the MIP was accessible to exogenous substrates. We see stoichiometric substitution with clean isosbestic points using small ligands such as carbonate, thiocyanate and ammonia. When iodide is used, we see a catalytic oxidation to triiodide and hypothesize that the polymer stabilizes the Cu1+ ion with respect to disproportionation.