In the present paper, we study the role of AlR3 (R = CH3, Cl) as cocatalyst
for the Ziegler-Natta reaction. DFT-GGA calculations show that the cocatal
yst facilitates the reduction of the titanium atoms by means of an exchange
between the R and Cl ligands. The reductions of the alkylated species of t
itanium are thermodynamically favorable.