Theoretical and Spectroscopic UV Study of the EtInd2ZrCl2/MAO, EtInd2ZrCl2/MAO-AlCl3 and EtInd2ZrCl2/MAO-Ethyl Benzoate Interaction

FERREIRA, M. L.; BELELLI, P. G.; DAMIANI, D. E.

MACROMOLECULAR CHEMISTRY AND PHYSICS

WILEY-V C H VERLAG GMBH

Año: 2001 vol. 202 p. 495 - 511

1022-1352

This work presents a theoretical and experimentalstudy of the active sites formation in the systemEtInd2ZrCl2/MAO. Results about the effect of additives asa Lewis acid (AlCl3) or a Lewis base (EB) are also analyzed.The theoretical study takes into account all theknown steps in the active site formation: alkylation of zirconocene,formation of a polarized complex metallocene:MAO, formation of a contact ion pair and finally a solventseparated ion pair. Other reactions of the zirconocene withother aluminium alkyls (AlCl3 and AlMe3) are also presentedand studied. UV-vis experimental results of theadditive effects are reported and explained taking intoaccount the theoretical results. A short review of ourresults and others is presented to complete and discuss theideas. The most probable sites are loosened contact ionpairs, not the solvent separated ion pairs.