Transition metal catalysts
View Patent ↗Transition metal catalysts comprise (a) a source of a Group 3 to 10 transition metal, (b) a ligand having the formula: R 1 R 2 X—Y—XR 3 R 4 wherein X is phosphorus, arsenic or antimony, Y is a bridging group having the formula: Z-(A)-D-R m wherein Z is the moiety linking the X groups, A is a linear or cyclic hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl linking group wherein the number of atoms directly linking Z to D is 1, 2 or 3, D is N, P, As, O, S or Se, R is hydrogen, alkyl, hydrocarbyl, substituted hydrocarbyl, heteroalkyl, heterohydrocarbyl or substituted heterohydrocarbyl, and m is 1 or 2, R 1 , R 2 , R 3 , and R 4 are the same or different and represent hydrocarbyl or functionalized hydrocarbyl moieties with the proviso that if D is nitrogen, R is not a cyclic ether, and optionally an activator. The transition metal catalysts are suitable for the selective trimerisation or tetramerisation of olefins in particular ethylene.
1. A catalyst system for the selective trimerisation or tetramerisation of olefins comprising
(a) a source of a Group 3 to 10 transition metal,
(b) a ligand having the formula:
R 1 R 2 X—Y—XR 3 R 4
wherein
X is phosphorus, arsenic or antimony,
Y is a bridging group having the formula:
Z-(A)-D-R m
wherein
Z is methylene, 1,2-ethane, 1,2-phenylene, 1,3-propane, 1,2 catechol or nitrogen,
A is a linear or cyclic hydrocarbyl, substituted hydrocarbyl, heterohydrocarbyl or substituted heterohydrocarbyl linking group wherein the number of atoms directly linking Z to D is 1, 2 or 3,
D is N, P, As, O, S or Se,
R is hydrogen, alkyl, hydrocarbyl, substituted hydrocarbyl, heteroalkyl, heterohydrocarbyl or substituted heterohydrocarbyl, and
m is 1 or 2,
R 1 , R 2 , R 3 , and R 4 are the same or different and represent hydrocarbyl or functionalized hydrocarbyl moieties with the proviso that if D is nitrogen, R is not a cyclic ether, and optionally
(c) an activator.
2. A catalyst system according to claim 1 wherein the Group 3 to 10 transition metal is a Group 6 transition metal.
3. A catalyst system according to claim 1 wherein the transition metal is chromium.
4. A catalyst system according to claim 1 wherein X is phosphorus.
5. A catalyst system according to claim 1 wherein D is oxygen.
6. A catalyst system according to claim 1 wherein R 1 , R 2 , R 3 , and R 4 are phenyl.
7. A catalyst system according to claim 1 wherein Y is
—N—(CH 2 ) 2 OCH 3 ,
—N—(CH 2 ) 3 OCH 3 ,
—N—(2-OCH 3 )C 6 H 4 or
—N—CH 2 (2-OCH 3 )C 6 H 4 .
8. A catalyst system according to claim 1 wherein component (b) is selected from the following
(C 6 H 5 ) 2 PN(CH 2 CH 2 OCH 3 )P(C 6 H 5 ) 2 ,
(C 6 H 5 ) 2 PN(CH 2 CH 2 CH 2 OCH 3 )P(C 6 H 5 ) 2 ,
(C 6 H 5 ) 2 PN((2-OCH 3 )C 6 H 4 )P(C 6 H 5 ) 2 and
(C 6 H 5 ) 2 PN(CH 2 (2-OCH 3 )C 6 H 4 )P(C 6 H 5 ) 2 .
9. A catalyst system according to claim 1 wherein the ratio of components (a) and (b) is between 10000:1 and 1:10000.
10. A catalyst system according to claim 9 wherein the ratio of components (a) and (b) is between 1.5:1 and 1:1.5.
11. A catalyst system according to claim 1 wherein the activator is an aluminoxane.
12. A catalyst system according to claim 1 wherein any of the components (a), (b) or (c) are supported.
13. A catalyst system according to claim 12 wherein the support is silica.
14. A catalyst for the trimerization/tetramerization and polymerization of olefins according to claim 1 further comprising one or more catalysts (d) suitable for the polymerization, oligomerization or other chemical transformation of olefins.
15. A catalyst according to claim 14 wherein catalyst (d) is selected from the group consisting of Ziegler-Natta catalysts, metallocene catalysts, chromium catalysts, late transition metal catalysts and single site catalysts.
16. A process for the trimerization or tetramerization of olefin monomer or olefin monomers performed in the presence of a catalyst system according to claim 1 .
17. A process according to claim 16 wherein the olefin monomer is ethylene.
18. A process according to claim 16 performed in the solution, slurry or gas phase.
19. A process according to claim 16 performed in the presence of an inert diluent or solvent.
20. A process according to claim 19 wherein the inert diluent or solvent is heptane, toluene, 1-hexene, diethyl ether, tetrahydrofuran, acetonitrile, dichloromethane, chloroform, chlorobenzene or methanol.
21. A process according to claim 16 wherein the inert diluent or solvent is a halogen-containing compound.
22. A process according to claim 21 wherein the halogen-containing compound is chlorobenzene or 1,2-dichlorobenzene.
23. A process according to claim 16 wherein the olefin monomer or olefin monomers are additionally contacted with a further catalyst (d) suitable for the polymerization, oligomerization or other chemical transformation of olefins.
24. A process according to claim 23 wherein the catalyst (d) is selected from the group consisting of Ziegler-Natta catalysts, metallocene catalysts, monocyclopentadienyl or “constrained geometry” catalysts, heat activated supported chromium oxide catalysts, late transition metal catalysts and single site catalysts.
25. A process according to claim 23 wherein the ratio of components (a) to (d) is in the range 10000:1 to 1:10000.
26. A process according to claim 25 wherein the ratio of components (a) to (d) is from 100:1 to 1:100.