Patent ID: 8367853

Claim:
A method for making a catalyst from a catalyst precursor, comprising: reacting a catalyst precursor with an η-5 type ligand complex to form a catalyst, wherein: the catalyst precursor has a general structure of: wherein: M is Zr or Hf; each x is independently selected from a hydrogen, alkyl, branched alkyl, cycloalkyl, aryl, or alkenyl group having from 2 to 20 carbons; n is 1, 2, 3, 4, 5, 6, 7, or 8; each c is independently selected from a hydrogen, alkyl, branched alkyl, cycloalkyl, aryl, or alkenyl group having from 2 to 20 carbons, or at least one c is joined with another c to form a ring; each Y is independently a halide or NR 2 , wherein each R is independently a hydrocarbyl group having from 1 to 5 carbons; the η-5 type ligand metal complex comprises a cyclopentadienyl, a substituted cyclopentadienyl, an indenyl, a substituted indenyl, a fluorenyl, or a substituted fluorenyl complexed with a group I or a group II metal; and the catalyst has a general structure of: wherein Cp is an η-5 type ligand comprising a cyclopentadienyl, a substituted cyclopentadienyl, an indenyl, a substituted indenyl, a fluorenyl, or a substituted fluorenyl.