A calorimetric investigation on the reactions of TiCl4 with phthalates in 1,1,2,2-tetrachloroethane (TCE) is presented in order to better understand the complex interactions present
in Ziegler-Natta catalytic systems. The Lewis bases diethyl isophthalate (L1), diethyl terephthalate (L2) and the ortho-isomer diethylphthalate (L3), have been chosen to study how the substituent positions could influence the energy and the stoichiometry of the complexation
FTIR spectroscopy was used to obtain information on the coordination mode of the ligands and diffusion measurements by NMR
was carried out to verify the presence of oligo-or polymeric species. Experimental results were compared with theoretical
calculations based on Density Functional Theory (DFT).