MOLECULAR MECHANICS AND THE POLYMERIZATION MECHANISM OF HOMOGENEOUS AND HETEROGENEOUS ZIEGLER-NATTA CATALYSTS

Examples of the application of simple molecular mechanics techniques to the study of the polymerization mechanism of various types of Ziegler-Natta catalysts are reported. Details are given on the new mechanism of enantioselectivity suggested by molecular mechanics studies. The validity of the latter, involving a ''chiral orientation of the growing chain'' which had never been suspected before, has been experimentally proved both for homogeneous and heterogeneous catalysis.