A density functional study of Ti/MgCl2-supported Ziegler-Natta catalysts

Total energy pseudopotential calculations have been used to examine the ads orption of TiCl4 at both the 110 and 100 surfaces of magnesium chloride. Ti tanium(IV) chloride is found to bind most strongly on the 100 surface resul ting in the formation of a complex with approximately trigonal bipyramidal coordination of titanium, which will dissociate to form TiCl3+ and Cl- with an energy of 127.7 kJmol(-1). Cluster calculations indicate that this site only weakly binds ethene, but does catalyse the formation of C-C bonds wit h an activation energy consistent with experimental estimates.