U.S. patent application number 09/778427 was filed with the patent office on 2001-08-23 for preparation of transition metal imine complexes.
Invention is credited to Arthur, Samuel D., Citron, Joel D., Ittel, Steven D..
Application Number | 20010016634 09/778427 |
Document ID | / |
Family ID | 22154954 |
Filed Date | 2001-08-23 |
United States Patent
Application |
20010016634 |
Kind Code |
A1 |
Ittel, Steven D. ; et
al. |
August 23, 2001 |
Preparation of transition metal imine complexes
Abstract
Transition metal imine complexes can be prepared by reacting the
imine precursors, a carbonyl compound and a primary amine, in the
presence of a selected transition metal compound. The complexes may
be used as catalysts for olefin polymerization.
Inventors: |
Ittel, Steven D.;
(Wilmington, DE) ; Arthur, Samuel D.; (Wilmington,
DE) ; Citron, Joel D.; (Wilmington, DE) |
Correspondence
Address: |
E I DU PONT DE NEMOURS AND COMPANY
LEGAL DEPARTMENT - PATENTS
1007 MARKET STREET
WILMINGTON
DE
19898
US
|
Family ID: |
22154954 |
Appl. No.: |
09/778427 |
Filed: |
February 7, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09778427 |
Feb 7, 2001 |
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09277910 |
Mar 29, 1999 |
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6232259 |
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60080051 |
Mar 31, 1998 |
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Current U.S.
Class: |
526/172 ;
502/155; 526/169.1 |
Current CPC
Class: |
C07F 15/025 20130101;
C07F 15/0066 20130101; C07F 15/045 20130101; C08F 110/02 20130101;
C07F 15/065 20130101; C08F 10/00 20130101; C08F 10/00 20130101;
C08F 4/7006 20130101 |
Class at
Publication: |
526/172 ;
502/155; 526/169.1 |
International
Class: |
C08F 004/70; B01J
031/06 |
Claims
What is claimed is:
1. A process for the production of a transition metal complex of an
imine, comprising, contacting under imine forming conditions in an
aprotic solvent, a transition metal compound, a first organic
compound containing at least one aldehyde or ketone group, and a
second organic compound which is a primary amine to form said
transition metal complex of said imine, and provided that said
transition metal is nickel, palladium, iron, or cobalt.
2. The process as recited in claim 1 wherein byproduct water is
removed by distillation or formation of a hydrate.
3. The process as recited in claim 1 wherein water is removed by
azeotropic distillation.
4. The process as recited in claim 1 or 3 wherein said second
compound is a primary aryl amine or a substituted aryl primary
amine.
5. The process as recited in claim 1 or 3 wherein said transition
metal is nickel.
6. The process as recited in claim 1 or 3 wherein said transition
metal compound is a chloride, bromide, or carboxylate.
7. The process as recited in claim 1 wherein a temperature is about
0.degree. C. to about 250.degree. C.
8. The process as recited in claim 1 wherein said aprotic solvent
is a hydrocarbon.
9. The process as recited in claim 1 or 3 additionally comprising
contacting said complex with one or more polymerizable olefins and
optionally cocatalysts to polymerize said polymerizable
olefins.
10. The process as recited in claim 9 wherein said complex is not
isolated before said contacting with one or more polymerizable
olefins.
11. The process as recited in claim 5 wherein said second compound
is a primary amine or a substituted aryl primary amine.
12. The process as recited in claim 6 wherein said second compound
is a primary amine or a substituted aryl primary amine.
13. The process as recited in claim 9 wherein said second compound
is a primary amine or a substituted aryl primary amine.
14. The process as recited in claim 6 wherein transition metal is
nickel.
15. The process as recited in claim 9 wherein transition metal is
nickel.
16. The process as recited in claim 9 wherein transition metal
compound is a chloride, bromide or carbonate.
17. The process as recited in claim 15 wherein transition metal
compound is a chloride, bromide or carbonate.
Description
FIELD OF THE INVENTION
[0001] Preparation of imine complexes of certain transition metals
from selected metal compounds and organic compounds which are
precursors of imines in essentially a single step are described.
The imine complexes are useful in the polymerization of olefins,
and may be used directly without isolation.
TECHNICAL BACKGROUND
[0002] Imine complexes of certain transition metals such as iron,
palladium, cobalt, nickel and others are important parts of
catalyst systems for the polymerization of olefins, see for
instance U.S. Pat. No. 5,714,556, World Patent Applications
96/23010, 97/48737, 97/48735, 97/38024, and U.S. patent application
Ser. No. 08/991,372, filed Dec. 16, 1997 all of which are hereby
included by reference. These and other references generally
describe the synthesis of these types of imine complexes as the
reaction of the imine containing ligand with various types of
transition metal compounds to form the transition metal imine
complex. These methods usually involve the use of substantially
anhydrous conditions to avoid hydrolysis of the starting transition
metal compound and/or any intermediates or the desired final
complex.
[0003] For the most part, the imines themselves are not
commercially available, usually being made from the corresponding
carbonyl compound, such as a ketone or aldehyde, and an amine,
often an aromatic amine. When made by this method, water is a
byproduct. Since this imine forming reaction is usually considered
to be an equilibrium, to drive the reaction to completion the water
is often removed during the synthesis of the imine, for example by
distillation, preferably azeotropic distillation, or by formation
of a hydrate, preferably an inorganic hydrate.
[0004] Thus imine complexes of transition metals are often made in
two step processes, imine synthesis, and then synthesis of the
metal complex. A simpler, especially one step, synthesis would be
preferable if they used the same starting materials since they
would usually be cheaper than a two step synthesis.
[0005] Many complexes of imines and transition metals have been
synthesized and reported in the literature. In addition to the
above references, see for instance: H. tom Dieck et al., Inorg.
Chim. Acta, vol. 177, p. 191-197 (1990); R. van Asselt, et al., J.
Am. Chem. Soc., vol. 116, p. 977-985 (1994); H. tom Dieck, et al.,
Z. Naturforsch. B, vol. 33, p. 1381 et seq. (1978); H. G. von
Schnering, et al., Chem. Ber., vol. 109, p. 1665 et seq. (1976);
and H. tom Dieck et al., Chem. Ber., vol. 109, p. 1657 et seq.
(1976).
[0006] R. van Asselt, et al., Recl. Trav. Chim. Pays-Bas., vol.
113, p. 88-98 (1994) describes the synthesis of certain zinc and
nickel .alpha.-diimine complexes from the diketone and aromatic
amine. In many of the syntheses, (glacial) acetic acid is
present.
SUMMARY OF THE INVENTION
[0007] This invention concerns a process for the production of a
transition metal complex of an imine, comprising, contacting under
imine forming conditions in an aprotic solvent, a transition metal
compound, a first organic compound containing at least one aldehyde
or ketone group, and a second organic compound which is a primary
amine to form said transition metal complex of said imine, and
provided that said transition metal is nickel, palladium, iron and
cobalt.
DETAILS OF THE INVENTION
[0008] It is well known that imines can be made by the reaction of
a carbonyl group such as a ketone or aldehyde with a primary amine,
the reaction being: 1
[0009] Since (1) is generally thought of as being an equilibrium
reaction, it is usually driven to completion (formation of the
imine) by removing the byproduct water that is formed. This can be
done in a variety of ways, for instance removing the water by
azeotropic distillation or as a hydrate of an inorganic salt. In
order to efficientlky utilize carbonyl compound and amine-used in
(1), they should preferably be present in the reaction in
approximately the same ratio as they are in the product.
[0010] It has suprisingly been found that imine complexes [the
imine(s) in the complex may contain one or more imine groups] of
certain transition metals can be made in an aprotic solvent by
addition of salts of those metals to a process in which reaction
(1) is being carried out, even though water is generated as a
byproduct. Thus reaction (1) is carried out in the presence of a
suitable salt of the desired transition metal. The ratio of
transition metal salt to the other ingredients is not critical, but
in order to efficiently utilize all of the ingredients the ratio of
moles transition metal compound to moles of the other reactants is
such that they are approximately the same as they are in final
desired imine complex. The transition metal compound is preferably
present at the beginning of the process, but may be added at any
time during the formation of the imine.
[0011] Useful transition metal compounds include metal halides,
especially chlorides and bromides, and carboxylates. Zerovalent
metal compounds that are not too sensitive to water may be used in
conjunction with a suitable oxidizing agent (which are known in the
art). Preferred transition metal compounds are halides, especially
chlorides and bromides.
[0012] Any transition metal may be used. Transition metals are
those metals in Groups 3-12 (IUPAC notation), and metals in Groups
3-11 are preferred and metals in Groups 8-10 are especially
preferred. Specific preferred transition metals are nickel, cobalt,
iron and palladium, and nickel is especially preferred.
[0013] Process conditions for forming imines are well known and
will be found in the various references cited in the Technical
Background section, and also in R. L. Reeves in S. Patai, Ed., The
Chemistry of the Carbonyl Group, Interscience Publishers, London,
1966, p. 608-619, and J. K. Whitesell in B. M. Trost, et al., Ed.,
Comprehensive Organic Synthesis, Vol. 6, Pergamon Press, Oxford,
1991, p. 719, which are both hereby included by reference.
[0014] The present process is preferably performed at a temperature
of about 0.degree. C. to about 250.degree. C., more preferably
about 20.degree. C. to about 130.degree. C. While pressure is not
critical, and the process will probably be most often be carried
out at ambient pressure, higher or lower pressures (than
atmospheric pressure) may be used, for example to control the
process temperature while distilling off byproduct water.
[0015] Preferred primary amines in the process are aryl amines,
i.e., R.sup.1 is an aryl or substituted aryl group. Aryl herein
includes groups that have one or more aromatic rings which may be
fused, as in naphthyl, or connected by a covalent bond, as in
2-phenylphenyl (o-biphenylyl). It is preferred that the aromatic
rings of the aryl group are carbocyclic rings, and it is more
preferred that R.sup.1 is phenyl or substituted phenyl. Useful
substitutents on a substituted phenyl group are alkyl, especially
alkyl containing 1 to 4 carbon atoms, halo, especially chloro,
phenyl, and halo substituted alkyl, especially fluoro substituted
alkyl. It is also preferred that the phenyl group be substituted in
the 2, or 2 and 6, positions.
[0016] The reaction is conducted in an aprotic solvent. By aprotic
is meant the solvent has no protons whose pKa is about 20 or more,
more preferably about 25 or more. Useful solvents include aromatic
hydrocarbons such as benzene and toluene, xylene, chlorobenzene and
o-dichlorobenzene. Since the transition metal complex may often be
used in conjunction with other types of compounds (such as alkyl
aluminum compounds) as a catalyst system for the polymerization of
olefin, the absence of protic solvents is an advantage, since the
solvent need not be removed before adding an alkyl aluminum
compound.
[0017] The carbonyl compound may contain more than one carbonyl
group which may form an imine. Useful carbonyl compounds include
.alpha.,.beta.-diones, 2,6-pyridinedicarboxyaldehydes,
2,6-diacylpyridines, cyclic .alpha.,.beta.-diones, 1,3-diones and
ketoaldehydes. Specific useful carbonyl compounds include glyoxal,
2,3-butanedione, acenapthenequinone, 2,6-diacetylpyridine,
2,6-pyridinedicarboxaldehyde, 1,2-cyclohexanedione, and
pyruvaldehyde.
[0018] The transition metal imine complex, after it is made, may be
isolated, as by removing the solvent under vacuum or by
crystallization, or the solution may be used directly (i.e.,
without isolation of the complex, but the solution may be filtered
to remove any insoluble impurities) in a polymerization of one or
more olefins. Olefins which may be polymerized with various
transition metal complexes of imines, and the conditions for
polymerizations will be found in U.S. Pat. No. 5,714,556, World
Patent Applications 96/23010, 97/48737, 97/48735, 97/38024, and
U.S. patent application Ser. No. 08/991,372, filed Dec. 16, 1997,
and other references.
[0019] In the Examples, all pressures are gauge pressures.
EXAMPLE 1
[0020] 2
[0021] Nickel dibromide was purified of insoluble material by
dissolving 2.22 g anhydrous nickel dibromide in 100 mL ethanol
containing 1 mL water, filtering through diatomaceous earth and
rotary evaporating dry. A mixture of 1.84 g (10.1 mmol)
acenapthenequinone, 3.00 g (20.0 mmol) 2,6-diethylaniline, 2.1 g
(9.6 mmol) nickel dibromide and 50 mL toluene was refluxed under
nitrogen with water removal for 24 h to give a deep red-black
reaction mixture. The mixture was rotary evaporated to remove
toluene and the concentrate was stirred with 50 mL methylene
chloride and filtered through diatomaceous earth to remove
unreacted nickel bromide. The filtrate was rotary evaporated and
then held under high vacuum to yield 4.84 g dark red, waxy solids.
The product was crushed and slurried in 40 mL hexane and
suction-filtered. Drying under nitrogen yielded 3.95 g (I) as a
brown, methylene chloride-soluble powder.
EXAMPLE 2
[0022] A suspension of 2.0 mg (0.0030 mmol) (I) of Example 1 in 5
mL dry, deaerated toluene was mixed with 1.0 mL 1.7M modified
methylaluminoxane in toluene (contains about 30% isobutyl groups)
in a septum vial under nitrogen, swirling occasionally over 5 min,
resulting in a dark maroon solution. A 600-mL stirred autoclave was
loaded with 200 mL dry toluene. The solvent was stirred and
saturated with ethylene at 50.degree. C. and 0.7 MPa for 10 min.
The autoclave was vented and the toluene solution of catalyst was
taken up into a 10-mL syringe and was injected into the autoclave
through a head port. The autoclave was immediately pressured to 1.0
MPa with ethylene and was stirred for 30 min in a 50.degree. C.
water bath as ethylene was fed to maintain pressure. After 30 min
the ethylene was vented and resulting clear polymer gel was
extracted with acetone and vacuum-oven dried (70.degree.
C./nitrogen purge) to yield 6.7 g polyethylene.
EXAMPLE 3
[0023] 3
[0024] A mixture of 1.84 g (10.1 mmol) acenaphthenequinone, 3.00 g
(20.0 mmol) 2,6-diethylaniline, 2.25 g (9.5 mmol) nickel dichloride
hexahydrate, 30 mg p-toluenesulfonic acid and 50 mL toluene was
refluxed for 48 h under nitrogen with water removal. The deep
red-brown reaction mixture was suction-filtered on a glass fritted
funnel to remove unreacted nickel dichloride. The black filtrate
solution was sparged with nitrogen before using as a catalyst.
EXAMPLE 4
[0025] A mixture of 20 mL dry, deaerated toluene and 1.0 mL 1.7M
modified methylalumoxane was magnetically stirred at room
temperature under 41 kPa ethylene in a 50-mL Schlenk flask for a
few minutes to saturate the solvent with ethylene. Then 1.5 mL of
the solution of (II) made in Example 10 was added; a black solution
immediately resulted. This solution was stirred under 41 kPa
ethylene for 16 h; it remained black but became more viscous with
time. The ethylene was vented and the solution was stirred with 25
mL 6N HCl and 20 mL additional toluene, and the toluene layer was
separated, water-washed and rotary-evaporated to yield, after
washing with methylene chloride and acetone and vacuum-oven drying
(70.degree. C.), 0.96 g of soft, tacky polyethylene.
* * * * *