Metal-lon-Templated Polymers: Synthesis and Structure of /V-(4-Vinylbenzyl)-1,4,7-Triazacyclononanezinc(ii) Complexes, Their Copolymerization with Divinylbenzene, and Metal-Ion Selectivity Studies of the Demetalated Resins-Evidence for a Sandwich Com

摘要

The innovative studies of Wulff. Mosbach and Shea, among others, introduced and further developed the concept of tem-plaled polymers, which initially involves a host guest relationship between a vinyl monomer host and a bound guest acting as a template. This host guest complex is then polymerized with a cross-linking agent, which then provides spatially regulated sites in the polymer matrix and. it is hoped, further allows continual recognition of the removable guest (the template) in subsequent reproduction experiments. One of the types of guest templates utilized in this elegant approach to highly selective polymers of defined architecture was metal ions. However, metal-ion-imprinted polymers have received much less attention than polymers imprinted with organic compounds; the following aspects, for example, need to be addressed: 1) the unequivocal structures of the complexes between the vinyl monomer as ligand and the metal ion: 2) polymerization parameters such as the effect of the metal ion. ligand structure, and the nature of the cross-linking agent: 3) the structure of ihe imprinted metal-ion site in the polymer; and 4) whether subsequent selectivity is a consequence of the metal-ion recognition process or the thermodynamic stability of the(polymeric ligand) (metal ion) complex.