GROUP 4 METALLOCENES USEFUL AS CATALYST FOR THE POLYMERIZATION OF OLEFINS

摘要

A 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-C20-hydrocarbyl, tri(C1-C20-alkyl)silyl, C6-C20-aryl, C7-C20-arylalkyl or C7-C20-alkylaryl; each R1 is a C4-C20 hydrocarbyl radical branched at the ß-atom to the cyclopentadienyl ring, optionally containing one or more heteroatoms belonging to groups 14-16, or is a C3-C20 hydrocarbyl radical branched at the ß-atom to the cyclopentadienyl ring where the ß-atom is an Si-atom; n is 0-3; each R18 is the same or different and may be a C1 -C20 hydrocarbyl radical optionally containing one or more heteroatoms belonging to groups 14-16; each R4 is a hydrogen atom or a C1-6 -hydrocarbyl radical; each W is a 5 or 6 membered aryl or heteroaryl ring wherein each atom of said ring is optionally substituted with an R5 groupeach R5 is the same or different and isa C1-C20 hydrocarbyl radical optionally containing one or more heteroatoms belonging to groups 14-16; and optionally two adjacent R5 groups taken together can form a further mono or multicyclic ring condensed to W optionally substituted by one or two groups R5.