Patent ID: 7956139

Claim:
A method of polymerizing olefins, comprising: contacting an α-olefin with a catalyst composition under polymerization conditions to form a polymer; wherein the catalyst composition comprises the contact product of an ansa-metallocene and an activator, wherein: the ansa-metallocene comprises a compound having the formula: (X 1 )(X 2 )(X 3 )(X 4 )M 1 , wherein: M 1 comprises titanium, zirconium, or hafnium; X 1 and X 2 independently comprise a substituted cyclopentadienyl, a substituted indenyl, or a substituted fluorenyl; one substituent on X 1 and X 2 comprises a bridging group having the formula E(Cyc), wherein E is a carbon atom, a silicon atom, a germanium atom, or a tin atom, and E is bonded to both X 1 and X 2 , and wherein Cyc is a substituted or an unsubstituted carbon chain of from 4 to 6 carbon atoms in length with each end connected to E to form a ring structure; one substituent on X 1 or X 2 comprises a substituted or an unsubstituted alkenyl group; X 3 and X 4 independently comprise: F, Cl, Br, or I; a hydrocarbyl group, H, or BH 4 ; a hydrocarbyloxide group, a hydrocarbylamino group, or a trihydrocarbylsilyl group; OBR A 2 or SO 3 R A , wherein R A is an alkyl group or an aryl group; and the activator comprises: an activator-support comprising a solid oxide treated with an electron-withdrawing anion, a layered mineral, an ion-exchangeable activator-support, or any combination thereof; an organoaluminoxane compound; an organoboron compound or an organoborate compound; or any combination thereof.