Modeling of isospecific Ti sites in MgCl2 supported heterogeneous Ziegler-Natta catalysts

Abstract

Diethers giving low II show stronger complexation on 100 than on 110 face of MgCl2. Stereoregulating donors exhibit a preferential selection of 110 face Mg atoms.Complexation of a diether adjacent to a Ti2Cl8 dimer on MgCl2 can convert an aspecific into an isospecific species. The most frequent defects in MgCl2 are steps in 10 faces and 120 ° corners between the two crystal faces. The number of 4-coordinate Mg atoms is generally greater than that of 5-coordinate ones.Three types of isospecific sites proposed, arising from donor interactions:Isospecific transformation involving donor, independent of type of donor.