Immobilization of metal complexes in porous organic hosts: A spectroscopic examination of site structure and development of materials for the storage and release of nitric oxide

Delivery of nitric oxide (NO) to specific targets is important in fundamental studies and therapeutic applications. The research described in this dissertation involves the development of network copolymers for the storage and release of NO. Template copolymerization of low-molecular weight molecules into highly cross-linked polymers has been used to create mono-dispersed immobilized sites in synthetic polymers.; Template copolymerization methods have been used to make materials for a variety of applications where site specific analyte binding is desired. In nearly every case, the structure of the binding site is crucial to the efficient function of the material. The immobilization of metal ion containing templates in amorphous hosts allows the use of spectroscopy to conveniently probe the site structure. Reported in Chapter 2 are results from spectroscopic studies for a series of monomeric cobalt complexes and related copolymers. Comparison of these data indicate that inert metal templates retain their structural properties after copolymerization and that site structure remains relatively unchanged even after the polymerized template has undergone chemical modification. The organic host prevents distortion of the immobilized ligand to geometries preferred by monomeric analogs.; Chapter 3 describes the application of these materials to the storage and release of NO, a known vasodilator. Slow release of NO (over the course of 30 days under ambient conditions) is observed for a polymer with immobilized CoII(salen) complexes. The physical and chemical features of this polymer have been probed using a variety of analytical tools. The spectroscopic properties, as well as the characteristics of the NO binding event are reported.; Chapter 4 discusses efforts to develop materials that dispense NO in a more controlled manner. For this new class of materials, the template design is based on biological systems found in nature. The immobilized complexes are inspired by proteins that store and release nitric oxide. There are several key architectural features found in the active sites of these proteins that promote the efficient release of NO. Efforts to incorporate molecular components, analogous to structural features of protein active sites, into a polymer host to produce materials with tunable NO binding/release properties are described.