| abstract |
A catalytic composition comprising the contact product of an ansa-metallocene and an activator, wherein: the ansa-metallocene comprises a compound having the formula: ** Formula ** wherein: M1 comprises zirconium or hafnium; X 'and X' 'are independently F, Cl, Br or I; E can be C or Si; R1 and R2 are phenyl groups; R3A and R3B are independently H or methyl; n is an integer from 1 to 2, inclusive; and R4A and R4B can independently be t-butyl or hydrogen group; The activator comprises: an activator-support comprising a solid oxide treated with an electron attractor anion, a layered mineral, an ion-exchangeable activator-support, or any combination thereof. |