OLIGOMERISATION OF ETHYLENE

Abstract

The present invention relates to a process for the oligomerisation of ethylene which comprises contacting ethylene with a transition metal-permethylpentalene complex, and a transition metal compound utilized therein.

Claims

1. A process for the oligomerisation of ethylene which comprises contacting ethylene with a transition metal-permethylpentalene derived complex.

2. The process according to claim 1, wherein the transition metal is chromium.

3. The process according to claim 1, wherein the reaction is carried out in solution in a non-polar organic solvent.

4. The process according to claim 1, wherein the transition metal-permethylpentalene derived complex is immobilised on a solid support material and the reaction is carried out in a slurry of the immobilised complex in a non-polar organic solvent.

5. The process according to claim 3, wherein the non-polar organic solvent is a liquid hydrocarbon.

6. The process according to claim 1, wherein ethylene is supplied at a pressure less than 10 atm.

7. The process according to claim 6, wherein ethylene is supplied at a pressure of 2 atm.

8. The process according to claim 1, wherein the transition metal complex is a complex of chromium and hydro(permethylpentalene) having the formula [Pn*(H)CrCl.sub.2].sub.2, where Pn* is a permethylpentalene moiety.

9. A compound having the formula [Pn*(H)CrCl.sub.2].sub.2.

10. A composition comprising the compound according to claim 9 immobilised on a solid support material.

11. The composition according to claim 10, wherein the solid support material comprises silica treated with methylaluminoxane.

12. The composition according to claim 10, wherein the solid support material comprises a layered double hydroxide treated with methylaluminoxane.

13. A method of making 1-octene or 1-hexene which comprises contacting ethylene with a transition metal-permethylpentalene derived complex.

14. (canceled)

15. A method of making an ethylene-olefin copolymer using a composition according to claim 10 as a first catalyst in combination with an ethylene polymerization catalyst as a second catalyst.

16. The composition according to claim 10, wherein the solid support material is silica treated with methylaluminoxane.

17. The composition according to claim 10, wherein the solid support material is a layered double hydroxide treated with methylaluminoxane.

Description

[0031] The invention is illustrated by the drawings in which:

[0032] FIG. 1: .sup.1H NMR spectroscopy (298K, benzene-d.sub.6) of oligomerisation of ethylene using [Pn*(H)CrCl2].sub.2

[0033] FIG. 2: GC Chromatogram (298K, dichloromethane) of the oligomerisation of ethylene using [Pn*(H)CrCl2].sub.2

EXAMPLE

[0034] (A) Synthesis of [Pn*(H)CrCl.sub.2].sub.2

[0035] To a slurry of CrCl.sub.3 (0.0981 g, 0.619 mmole) in benzene was added a solution of Pn*(H)SnMe.sub.3 (0.218 g, 0.619 mmole) in benzene. The reaction mixture was heated to 80 C. for 5 days to afford a dark-green solution. The reaction mixture was filtered and the volatiles were removed in vacuo to afford a dark-green powder which was washed with pentane and dried under reduced pressure to yield [Pn*(H)CrCl.sub.2].sub.2 as a dark-green powder. The complex is paramagnetic. The yield was 67%.

(B) Characterisation of [Pn*(H)CrCl.sub.2].sub.2

[0036] .sup.1H NMR spectrum (C.sub.6D.sub.6, 23 C.) =range of 36.0-18.3 ppm.

(C) Oligomerisation of Ethylene

[0037] (1) The complex [(Pn*(H)CrCl.sub.2].sub.2 was dissolved in benzene-d.sub.6 and the solution was maintained at a temperature of 110 C. Ethylene was supplied under a pressure of 200 kPa into the solution for one hour. The resulting solution was subjected to .sup.1H NMR spectroscopy (298 K, benzene-d.sub.6) to study the products of the oligomerisation reaction. The .sup.1H NMR spectrum is shown in FIG. 1. The .sup.1H NMR spectrum indicates the presence of only oct-1-ene.

[0038] (2) The complex [Pn*(H)CrCl.sub.2].sub.2 was also used in solution in toluene to catalyse the oligomersiation of ethylene at a temperature of 80 C. for 2 hours at 200 kPa.

[0039] FIG. 2 shows a GC chromatogram (298 K, dichloromethane) of the oligomerisation. FIG. 2 highlights the presence of 1-hexene and higher oligomers.

[0040] The above examples for oligomerisation indicate that utilizing the transition metal-permethyl penthalene derived complex in the oligomerisation of ethylene provides an extremely selective oligomerisation, only 1-octene was produced in example 1.

[0041] The features disclosed in the foregoing description, in the claims and in the accompanying drawings may both separately or in any combination be material for realizing the invention in diverse forms thereof.