Catalyst composition and process for oligomerization of ethylene
View Patent ↗The present invention relates to a catalyst composition comprising: (a) a binuclear chromium(II) complex; (b) a ligand of the general structure (A) R 1 R 2 P—N(R 3 )—P(R 4 )—N(R 5 )—H or (B) R 1 R 2 P—N(R 3 )—P(R 4 )—N(R 5 )—PR 6 R 7 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from halogen, amino, trimethylsilyl, C 1 -C 10 -alkyl, aryl and substituted aryl, wherein the PNPN- or PNPNP-unit is optionally part of a ring system; and (c) an activator or co-catalyst, as well as to a process for oligomerization of ethylene.
1. A catalyst composition comprising:
(a) a binuclear chromium(II) complex;
(b) a ligand of the general structure
(A) R 1 R 2 P—N(R 3 )—P(R 4 )—N(R 5 )—H or
(B) R 1 R 2 P—N(R 3 )—P(R 4 )—N(R 5 )—PR 6 R 7 ,
wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from halogen, amino, trimethylsilyl, C 1 -C 10 -alkyl, aryl and substituted aryl; and
(c) an activator or co-catalyst.
2. The catalyst composition according to claim 1 , wherein the binuclear chromium complex has a Cr—Cr-bond or two chromium centers connected via a bridging ligand.
3. The catalyst composition according to claim 2 , wherein the binuclear chromium complex is selected from:
4. The catalyst composition according to claim 3 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are selected from chloro, amino, trimethylsilyl, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, tolyl and xylyl.
5. The catalyst composition according to claim 4 , wherein the activator or co-catalyst is selected from trimethyl aluminium, triethyl aluminium, triisopropyl aluminum, triisobutyl aluminium, ethylaluminum sesquichloride, diethylaluminum chloride, ethyl aluminium dichloride and methylaluminoxane (MAO), or mixtures thereof.
6. The catalyst composition of claim 5 , further comprising a solvent selected from the group consisting of aromatic hydrocarbons, straight-chain and cyclic aliphatic hydrocarbons, straight-chain olefins and ethers, toluene, benzene, ethyl benzene, cumene, xylenes, mesitylene, hexane, octane, cyclohexane, methylcyclohexane, hexene, heptene, octene, diethylether and tetrahydrofurane, or mixtures thereof.
7. The catalyst composition of claim 6 , wherein the PNPN or the PNPNP unit in the ligand is part of a ring system.
8. The catalyst composition according to claim 2 , wherein the ligand is selected from (Ph) 2 P—N(i-Pr)—P(CH 3 )—N(i-Pr)—H, (Ph) 2 P—N(i-Pr)—P(Ph)—N(i-Pr)—H, (Ph) 2 P—N(i-Pr)—P(Ph)—N(Ph)—H, (Ph) 2 P—N(i-Pr)—P(Ph)—N(tert-butyl)-H and (Ph) 2 P—N(i-Pr)—P(Ph)—N(CH(CH 3 )(Ph))—H.
9. The catalyst composition according to claim 8 , further comprising a solvent selected from the group consisting of aromatic hydrocarbons, straight-chain and cyclic aliphatic hydrocarbons, straight-chain olefins and ethers, toluene, benzene, ethyl benzene, cumene, xylenes, mesitylene, hexane, octane, cyclohexane, methylcyclohexane, hexene, heptene, octene, diethylether and tetrahydrofurane, or mixtures thereof.
10. The catalyst composition according to claim 9 , wherein the solvent is toluene.
11. A process for oligomerization of ethylene, comprising contacting ethylene with a catalyst composition according to claim 9 , at a temperature of from 20 to 100° C. and a pressure from 10 to 50 bar.
12. The process according to claim 11 , wherein the binuclear chromium complex is selected from:
13. Process according to claim 12 , wherein the solvent is toluene.
14. The process according to claim 13 , wherein the process is carried out continuously and the mean residence time of the contacting of ethylene with said catalyst composition is from 1 to 4 hours.
15. The catalyst composition of claim 2 , wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are selected from the group consisting of chloro, amino, trimethylsilyl, methyl, ethyl, isopropyl, tert-butyl, phenyl, benzyl, tolyl and xylyl and the ligand is selected from the group consisting of (Ph) 2 P—N(i-Pr)—P(CH 3 )—N(i-Pr)—H, (Ph) 2 P—N(i-Pr)—P(Ph)—N(i-Pr)—H, (Ph) 2 P—N(i-Pr)—P(Ph)—N(Ph)—H, (Ph) 2 P—N(i-Pr)—P(Ph)—N(tert-butyl)-H and (Ph) 2 P—N(i-Pr)—P(Ph)—N(CH(CH 3 )(Ph))—H.
16. The catalyst composition of claim 15 , further comprising a solvent selected from the group consisting of aromatic hydrocarbons, straight-chain and cyclic aliphatic hydrocarbons, straight-chain olefins and ethers, toluene, benzene, ethyl benzene, cumene, xylenes, mesitylene, hexane, octane, cyclohexane, methylcyclohexane, hexene, heptene, octene, diethylether and tetrahydrofurane, or mixtures thereof.
17. The catalyst composition of claim 15 , wherein the activator or co-catalyst is selected from the group comprising trimethyl aluminium, triethyl aluminium, triisopropyl aluminum, triisobutyl aluminium, ethylaluminum sesquichloride, diethylaluminum chloride, ethyl aluminium dichloride and methylaluminoxane (MAO), or mixtures thereof.
18. The catalyst composition of claim 17 , wherein the solvent is toluene.
19. The catalyst composition of claim 18 , wherein the PNPN or the PNPNP unit in the ligand is part of a ring system.
20. A process for making a catalyst composition, combining at least:
(a) a binuclear chromium(II) complex;
(b) a ligand of the general structure
(A) R 1 R 2 P—N(R 3 )—P(R 4 )—N(R 5 )—H or
(B) R 1 R 2 P—N(R 3 )—P(R 4 )—N(R 5 )—PR 6 R 7 ,
Wherein R 1 , R 2 , R 3 , R 4 , R 5 , R 6 and R 7 are independently selected from halogen, amino, trimethylsilyl, C 1 -C 10 -alkyl, aryl and substituted aryl; and
(c) an activator or co-catalyst.