Metallocenes and catalysts for olefin-polymerisation

A metallocene of formula (I):

• (ZR1m)n(CP)(A)MLpL′q (I)
• wherein (ZR1m)n is a divalent group bridging Cp and A, Z being C, Si, Ge, N or P, and the R1 groups, equal or different from each other, being H or linear or branched, saturated or unsaturated C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl or C7-C20 arylalkyl groups;
• Cp is a heterocyclic cyclopentadienyl group of formula (II) or (II′):
• 29
• 30
• wherein one of X or Y is a single bond, the other being O, S, NR6 or PR6, R6 being hydrogen, a linear or branched, saturated or unsaturated C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C1-C20 alkylaryl or C7-C20 arylalkyl groups, optionally containing one or more atoms belonging to groups 13-16 of the Periodic Table of the Elements;
• R2 and R3, equal or different from each other, are selected from the group consisting of hydrogen, halogen, linear or branched, saturated or unsaturated C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C6-C20 alkylaryl, C7-C20 arylalkyl, —OR6, —OCOR6, —SR6, —NR62 and —PR62, wherein R6 has the meaning reported above;
• or R2 and R3 form together a condensed C5-C7 ring, saturated, unsaturated or aromatic, optionally containing one or more atoms belonging to groups 13-16 of the Periodic Table of the Elements;
• the substituents R4, equal or different from each other, are selected from the group consisting of halogen, linear or branched, saturated or unsaturated C1-C20 alkyl, C3-C20 cycloalkyl, C6-C20 aryl, C7-C20 alkylaryl, C7-C20 arylalkyl, —OR6, —OCOR6, —SR6, —NR62 and —PR62, wherein R6 has the meaning reported above, optionally containing one or more atoms belonging to groups 13-16 of the Periodic Table of the Elements;
• a is an integer ranging from 0 to 4;
• or Cp is a partially hydrogenated derivative of the heterocyclic group of formula (II) or (II′);
• A is a substituted or unsubstituted cyclopentadienyl, a group —NR6, R6 having the meaning reported above, or corresponds to (II) or (II′), or to a partially hydrogenated derivative of (II) or (II′);
• M is a transition metal belonging to group 3, 4, 5, 6 or to the lanthanide or actinide groups of the Periodic Table of the Elements;
• the substituents L, same or different from each other, are monoanionic sigma ligands selected from the group consisting of hydrogen, halogen, —R6, —OR6, —OCOR6, OSO2CF3, —SR6, —NR62 and —PR62, wherein the groups R6, same or different from each other, have the meaning reported above;
• the substituents L′, same or different from each other, are coordinating molecules;
• m is 1 or 2, being 1 when Z is N or P, and being 2 when Z is C, Si or Ge;
• n is an integer ranging from 0 to 4;
• r is 0 or 1;;
• n is 0 when r is 0;
• p and q are integers ranging from 0 to 3, p being equal to the valence of the metal M minus 2 when r=1, and minus 1 when r=0, and p+q being ≦3.