posted on 2016-05-09, 00:00authored byClaudio De Rosa, Rocco Di Girolamo, Giovanni Talarico
Originally
developed on heterogeneous Ziegler–Natta (ZN)
catalysts, the model of “chiral growing chain conformation”
developed by Corradini to explain the origin of stereocontrol in propene
polymerization was extended to all stereoselective polymerization
catalysts. The idea that the chiral recognition is performed by the
site-chirality through the conformation of growing
chain represents the “marker” of ZN toward, for example,
asymmetric catalysis in which a chiral host molecule recognizes directly two enantiomeric guest molecules. In this paper,
by using DFT calculations, we show that the origin of the stereocontrol
for the new generation of Hf(IV)-pyridylamido-based catalysts is somewhat
different and more similar to the asymmetric catalysis.