ИСТИНА

A racemic complex of formula (I), wherein M is zirconium or hafnium; each X is a sigma ligand; L is a divalent bridge selected from -R'2C-, -R'2C-CR'2, -R'2Si-, -R'2Si-SiR'2-, -R'2Ge-, wherein each R' is independently a hydrogen atom, C1-20-hydrocarbyl, tri(C1-20-alkyl)silyl, C6-20-aryl, C7-20-arylalkyl or C7-20-alkylaryl; R2 and R2' are each independently a C1-20 hydrocarbyl radical optionally containing one or more heteroatoms from groups 14-16; R5' is a C1-20 hydrocarbyl group optionally containing one or more heteroatoms from groups 14-16 and optionally substituted by one or more halo atoms.