Patent ID: 6884901

Claim:
A method for producing a Group 8 (VIII) metallocene compound, comprising the steps of: a) reacting a metal salt (MX n ) compound, a Cp compound and a ligand (L) to form an intermediate compound; and b) reacting the intermediate compound with a Cp′ compound to produce the metallocene compound, wherein, M is selected from the group consisting of Ru, Os and Fe; L is an electron pair donor; Cp and Cp′ are η n -coordinated moieties that and are both unsubstituted or either or both of Cp and Cp′ includes at least one substituent that is selected form the group consisting of: X; C a1 H b1 X c1 ; C a2 H b2 X c2 (C═O)C a1 H b1 X c1 ; C a2 H b2 X c2 OC a1 H b1 X c1 ; C a2 H b2 X c2 (C═O)OC a1 H b1 X c1 ; and C a2 H b2 X c2 O(C═O)C a1 H b1 X c1 ; where X is F, Cl, Br, I or NO 2 ; a1 is an integer from 1 to 8; b1 is an integer from 0 to 2(a1)+1−c1; c1 is an integer from 0 to 2(a1)+1−b1; b1+c1 is at least 1; a2 is an integer from 0 to 8; b2 is an integer from 0 to 2(a2)+1−c2; c2 is an integer from 0 to 2(a2)+1−b2.