Late Transition Metal Complexes: Catalysts for a New Generation of Organic Polymers

摘要

Since the pioneering by Karl Ziegler and Giulio Natta in the the early 1950s on the polymerization of simple olefins, there has been intense interest in the application 01 early transition metal catalysts for the selective polymerization of inexpensive oleflns. Current studies or metallocene-based catalysts have far-reaching implications for the development of new poly(x-olefin) materials as well as for an understanding of basic reaction mechanisms responsible for the growth of polymer chains at a catalyst center and for the control of polymer microstructures and molecular weights. However, due to the sensitivity of early transition metal complexes to electron-donating functional groups, this catalyst generation allows only the use of a limited number of polar monomers bearing stericaliy hindered functionalities. Thus, copolymers of readily available polar monomers with ethene are exclusively produced by radical routes in high-pressure processes.