ИСТИНА |
Войти в систему Регистрация |
|
ИПМех РАН |
||
A catalyst comprising (i) an asymmetric complex of formula (I) ** Formula ** in which 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-, in which each R 'is independently a hydrogen atom, C1-C20 alkyl, tri (C1-C20 alkyl) silyl, C6-C20 aryl, C7-C20 aryl-alkyl or C7-C20-aryl alkyl; R2 and R2 'are each independently C1-10 linear hydrocarbyl; R5 and R5 'are each independently hydrogen or a C1-20 hydrocarbyl group; R6 and R6 'are each independently hydrogen or a C1-20 hydrocarbyl group; R7 is hydrogen or a C1-20 hydrocarbyl group or is ZR3; Z is O or S, preferably O; R3 is a C1-10 hydrocarbyl group; Ar is an aryl or heteroaryl group having up to 20 carbon atoms optionally substituted with one or more R8 groups; Ar 'is an aryl or heteroaryl group having up to 20 carbon atoms optionally substituted with one or more R8' groups; R8 and R8 'are each independently a C1-20 hydrocarbyl group; with the proviso that at least one of R6 or R7 is not H; and (ii) a cocatalyst comprising a compound of a group 13 metal, for example boron.