Hafnocene catalyst compounds and process for use thereof

A catalyst compound represented by the formula (B):

• where:
• each R1, R2, R3, R4, R5, R6, R7, R8, R9 and R10 is, independently, hydrogen, alkoxide, a C1 to C40 substituted or unsubstituted hydrocarbyl group or is —R20—SiR′3 or —R20—CR′3 where R20 is a C1 to C4 hydrocarbyl, and each R′ is independently a C1 to C20 substituted or unsubstituted hydrocarbyl, provided that at least one R′ is not H, and provided that at least one of R1, R2, R4, R5, R6, R7, R8, R9 and R10 is —R20—SiR′3 or —R20—CR′3;
• and
• each X is, independently, a univalent anionic ligand, or two X are joined and bound to the metal atom to form a metallocycle ring, or two X are joined to form a chelating ligand, a diene ligand, or an alkylidene ligand, provided that X is not fluorine.