Catalysts
A complex of formula (I) wherein M is zirconium or hafnium; each X independently is a sigma ligand; 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 or a C 1 -C 20 -hydrocarbyl .group optionally containing one or more silicon atoms or heteroatoms of Group 14-16 of the periodic table or fluorine atoms, and optionally two R′ groups taken together can form a ring; R 2 and R 2′ are each independently a C 1 -C 20 hydrocarbyl group, —OC 1-20 hydrocarbyl group or —SC 1-20 hydrocarbyl group; R 5 is a —OC 1-20 hydrocarbyl group or —SC 1-20 hydrocarbyl group, said R 5 group being optionally substituted by one or more halo groups; R 5′ is hydrogen or a C 1-20 hydrocarbyl group; —OC 1-20 hydrocarbyl group or —SC 1-20 hydrocarbyl group; said C 1-20 hydrocarbyl group being optionally substituted by one or more halo groups; R 6 and R 6′ are each independently a C 1-20 hydrocarbyl group; —OC 1-20 hydrocarbyl group or —SC 1-20 hydrocarbyl group; each R 1 and R 1′ are independently —CH 2 R x wherein R x are each independently H, or a C 1-20 hydrocarbyl group, optionally containing heteroatoms.
1. A complex of formula (II)
wherein
M is zirconium or hafnium;
each X is independently a hydrogen atom, a halogen atom, a C 1-6 alkoxy group, a C 1-6 alkyl group, a phenyl group, or a benzyl group;
R 2 and R 2′ are each independently a C 1 -C 10 alkyl group;
R 5′ is hydrogen or ZR 3′ ;
Z is O or S;
R 3 and R 3′ are each independently a C 1-10 linear or branched alkyl, C 2-10 alkenyl, C 3-10 cycloalkyl, C 3-10 cycloalkenyl, C 6-10 aryl, C 7-10 alkylaryl, or C 7-10 arylalkyl group, optionally substituted by one or more halo groups;
R 6 and R 6′ are each independently a C 1-10 alkyl group or a C 6-10 aryl group;
each R 8 is independently a C 1-20 hydrocarbyl group or wherein two R 8 groups taken together with the atoms to which they are attached form a ring; and
each R x is independently H or a C 1-10 alkyl group.
2. The complex as claimed in claim 1 , wherein R 2 and R 2′ are independently a linear or branched C 1-6 alkyl group.
3. The complex as claimed in claim 1 , wherein R 6 and R 6′ are independently a linear or branched C 1-10 alkyl group.
4. The complex as claimed in claim 1 , wherein R 6 is a branched C 3-8 alkyl group, and R 6′ is a linear C 1-8 alkyl group or branched C 3-8 alkyl group.
5. The complex as claimed in claim 1 , wherein:
R 3 is a C 1-6 alkyl group; and
R 3′ is a C 1-6 alkyl group.
6. The complex as claimed in claim 1 , wherein each R x is H or C 1-6 alkyl.
7. The complex as claimed in claim 1 , wherein said complex is of formula (IIIa) or formula (IIIb):
wherein
each R 8 is independently a C 1-6 alkyl group or C 3-7 cycloalkyl group;
R 6 is a C 1-10 alkyl group;
R 6′ is a C 1-10 alkyl group;
R 5′ is hydrogen or OR 3 ; and
R 2 and R 2′ are independently a C 1-6 alkyl.
8. The complex as claimed in claim 1 , wherein said complex is of formula (IVa) or formula (IVb):
wherein
each R x is independently H or a C 1-4 alkyl group.
9. The complex as claimed in claim 1 , wherein said complex is of formula (V):
wherein
each R x is independently H or methyl; and
R 6′ is a linear or branched C 1-4 hydrocarbyl group.
10. The complex as claimed in claim 1 , wherein the complex is symmetrical.
11. The complex as claimed in claim 1 , wherein the complex is of formula
12. A catalyst comprising
(i) the complex as claimed in claim 1 ; and
(ii) a cocatalyst comprising a compound of a group 13 metal.
13. The catalyst of claim 12 , wherein the catalyst is a solid catalyst.
14. A process for the manufacture of the catalyst as claimed in claim 12 , the process comprising:
forming a liquid/liquid emulsion system, which comprises a solution of catalyst components (i) and (ii) dispersed in a solvent so as to form dispersed droplets, and
solidifying said dispersed droplets to form solid particles.
15. The catalyst of claim 12 , wherein the catalyst is supported on silica.
16. A process for the polymerization of at least one olefin, the process comprising reacting said at least one olefin with the catalyst as claimed in claim 12 .