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) dichloroziron ium, were designed in terms of the mechanism and concept of the activity an d selectivity of metallocenes. The predictions on which the designs were ba sed were carried out for four metallocene catalysts through molecular model ing methods such as molecular mechanics and charge equilibrium. In a compar ison of the data from three of the catalysts that were successfully synthes ized, 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. (C) 2000 John Wiley & Sons, Inc.