Catalyst structure for olefin polymerization

摘要

A catalyst system having the following formula is described herein. wherein M is a metal; each X is an atom or group banded to M and may be the same or different; R₁ and R₂ may be the same or each may be different and are substituted or unsubstituted cyclopentadienyl or aromatic groups; R_B is a structural bridge between R₁ and R₂ imparting stereorigidity thereto and including at least one heteroatom bonded to M, with each of R₁ and R₂ bonded to the same or different heteroatom of R_B which heteroatom is also bonded to M; Z is the coordination number of M and is greater than or equal to 4 and m is the number of bonds between M and heteroatoms of R_B.