| abstract |
A catalyst in solid particulate form free from an external carrier material comprisingn (I) a complex of formula (I) nn n n n n n n n n n n n wherein n M is zirconium or hafnium; n each X is a sigma ligand; n L is a divalent bridge selected from —R′ 2 C—, —R′ 2 C—CR′ 2 —, —R′ 2 Si—, —R′ 2 Si—SiR′ 2 —, —R′ 2 Ge—, wherein each R′ is independently a hydrogen atom, C1-C20-alkyl, tri(C1-C20-alkyl)silyl, C6-C20-aryl, C7-C20-arylalkyl or C7-C20-alkylaryl; n each R 2 is independently hydrogen or a C1-C20 hydrocarbyl radical provided that at least one R 2 is not hydrogen; n each R 5 is independently hydrogen or a C1-20 hydrocarbyl group optionally containing one or more heteroatoms from groups 14-16; n each R 6 is independently hydrogen or a C1-20 hydrocarbyl group optionally containing one or more heteroatoms from groups 14-16; n each n is independently 1, 2 or 3; and n each R 8 is a C1-20 hydrocarbyl group; n and (ii) a cocatalyst comprising a compound of a group 13 metal, e.g. Al or boron. |