CATALYTIC METALLO-BIOMIMETIC SITES IN POROUS HOSTS

点击翻译按钮获取中文摘要

The aim of this proposed research is to develop new biomimetic catalysts by immobilizing metal complexes in porous organic hosts. The research will emphasize oxygenase chemistry especially those reactions involving C-H bond activation and epoxidation to produce optically pure molecules of potential pharmaceutical importance. The proposed systems will be made using a template copolymerization methodology where the formation of the immobilized sites occurs during polymerization. We propose that this method is an effective way to model metal sites found in proteins and that systems can be designed to simulate various architectural features found in metalloproteins, including site isolation of catalytic metal sites, porosity, and control of the microenvironments around the metal complexes. The unique microenvironments around the catalytic metal sites are created during polymerization and are maintained by the organic hosts after systems are formed. These highly structured active sites can be used to regulate exogenous ligand binding (and subsequent chemistry) to the immobilized metal complexes. Thus biomimetic inorganic species can be produced that are not normally observed in solution-derived, low molecular weight complexes. The long-range objective of this work is to design and synthesize systems that contain exogenous ligand (substrate) selectivity found in proteins yet are able to function under conditions where most biomolecules are unstable and inactive. Metalloproteins perform chemical reactions that have yet to be achieved in synthetic systems. This chemical versatility follows at least in part from the ability of the proteins to regulate the reactivity of their metal centers by adjustments of their microenvironment. Thus the function and disfunction of biologically-important metalloproteins can be understood in the context of changes in their microenvironments. This type of analysis necessitates basic reactivity studies in which the effects of single components can be analyzed individually as described herein.