Journal of Polymer Science Part A: Polymer Chemistry, Vol.38, No.12, 2232-2238, 2000
Molecular modeling on the prediction of silolene-bridged indenyl metallocene catalysts for isotactic polypropylene
Two new silolene-bridged metallocenes for isotactic polypropylene, racemic (1,4-butanediyl) silylene-bis (1-eta(5)-2-methyl-indenyl) dichlorozironium and racemic diphenyl silylene-bis (1-eta(5)-2-methyl-indenyl) dichlorozironium, were designed in terms of the mechanism and concept of the activity and selectivity of metallocenes. The predictions on which the designs were based were carried out for four metallocene catalysts through molecular modeling methods such as molecular mechanics and charge equilibrium. In a comparison of the data from three of the catalysts that were successfully synthesized, the predicted orders of the activity and selectivity were consistent. This shows that classical methods such as charge equilibrium are useful in predicting the activity of catalysts.
Keywords:metallocene;silolene bridge;activity;isotacticity;molecular mechanics;charge equilibration method