The dynamics study of metallocene catalyst using molecular dynamics

Molecular dynamics MD.simulation was applied to investigate the dynamics of metallocene catalyst. We introduced a cocatalyst, large substituents on cyclopentadienyl Cp.ring, and a longer polymer chain, along with a cationic active center. The study on interaction between the active center and the cocatalyst revealed that one or two fluorines of C6F5.4By are coordinated to the unsubstituted coordination space in the most stable state. A metastable state was also found, where C6F5.4By interacts with the whole active center, and moreover one or two fluorines come closer to a Si atom. The mobility of the polymer chain bonded to a higher isospecific metallocene active center was found to be more retarded than that bonded to a lower stereospecific metallocene active center. The investigation of the dynamics of polymer chain using our MD simulations would allow us to predict the stereospecificity of various metallocene catalysts. q1998 Elsevier Science B.V. All rights reserved.