Managing Tight Binding Receptors for New Separations Technologies (open access)

Managing Tight Binding Receptors for New Separations Technologies

An Imprinting System based on Hydrogen Bonding. In our first explorations we chose to use a tetradentate macrocyclic ligand, N,N',N'',N'''-tetra(2- carbamoylethyl)-1,4,8,11- tetraazacyclotetradecane (4cyclam), to provide strong metal ion binding, with four appended arms that terminate in amide functions to provide hydrogen bonding with corresponding groups in the polymer (Structure 1). Nickel(II) ion was chosen for these studies because of the kinetic inertness of the square planar complexes it forms with tetraazamacrocycles. Because covalent interactions tend to involve slow kinetics we use those that are non-covalent for the affinity between the MIP and the imprinting metal complex. The immediate issue is ''can non-covalent interactions be strong enough to produce the proposed new methodology''? The literature indicates that imprinting using, for example, hydrogen bonding supports only 10 to 15%, certainly less than 20%, re-binding capacity. An equally compelling issue is the relationship of the combined advantages of selective complex formation and selective binding of the complex to the polymer. Further, are these macroporous polymers durable enough to be used in a separations methodology? In considering these issues, binding and selectivity have been studied at both the complex formation and the polymer/imprint level.
Date: June 14, 2003
Creator: Busch, Daryle H. & Givens, Richard S.
System: The UNT Digital Library