Bisimidino compounds and the transitional metal complexes...

Details Bisimidino compounds and the transitional metal complexes... Bisimidino compounds and the transitional metal complexes...

2002-02-19

2004-11-16

Wu, David W. (Department: 1713)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Polymers from only ethylenic monomers or processes of...

C526S161000, C548S566000, C548S569000, C546S329000

Reexamination Certificate

active

06818715

ABSTRACT:

The present invention relates to bisimidine compounds, a process for their preparation, bisimidinato complexes as catalysts, a process for preparing them and their use in the polymerization of unsaturated compounds.
There is great interest in the development of novel families of catalysts for the polymerization of unsaturated compounds in order to obtain better control over the properties of polyolefins or further novel products.
Use of transition metal compounds as catalytically active substances for the polymerization of unsaturated compounds has been known for a long time. For example, Ziegler-Natta or Phillips catalysts are used commercially for the synthesis of polyolefins. More recently, metallocenes are being used as highly active polymerization catalysts. The metallocenes make it possible to obtain polymers having a narrow molecular weight distribution and copolymers having a uniform comonomer content.
However, metallocene catalysts have disadvantages for industrial use. For example, they are very sensitive to impurities in commercially available monomers, in the process gas and in the solvents used and to hydrolysis. Furthermore, the price of metallocenes having zirconium as central metal is very high.
It has been known for some time that new types of iron and cobalt complexes containing bisimidine ligands are very active as catalysts in the polymerization of unsaturated compounds.
V. C. Gibson et al., Chem. Commun. 1998, 849-850, and M. Brookhart et al., J. Am. Chem. Soc. 1998, 120, 4049-4050, disclose new olefin polymerization catalysts based on Fe(II) and Co(II). These catalysts contain 2,6-bis(imino)pyridyl ligands which are aryl-substituted on the imino nitrogens and display high activities in the polymerization of ethylene. The polyethylene obtained is essentially linear and the molecular weight is strongly dependent on the substituents on the alkyl radical.
WO 99/12981 describes bisimidinato complexes, their synthesis and their use in the polymerization of unsaturated compounds. Numerous complexes having a variety of different radicals are disclosed.
Examples 30 and 31 disclose complexes of the formula A in which R=CH
3
and C
6
H
5
. However, the demonstrated activities in the polymerization of ethylene are much too low for industrial applications.
It is an object of the present invention to provide novel complexes containing a metal of groups 7, 8, 9 or 10 of the Periodic Table of the Elements (late transition metal) as central metal which can be used for the polymerization of unsaturated compounds and give branched polymers in the polymerization. This object can be subdivided into the provision of a ligand system for this catalyst and a process for preparing this ligand system and the provision of a process for preparing the corresponding catalyst.
We have found that this object is achieved by compounds of the formula (I)
where the symbols have the following meanings:
A is a nonmetal selected from among N, S, O and P,
R
1
is a radical of the formula NR
5
R
6
,
R
2
is a radical of the formula NR
5
R
6
or NR
7
R
8
, where R
5
and R
6
are selected from among alkyl, aryl and cycloalkyl, and
R
5
and R
6
together with the N atom form a 5-, 6- or 7-membered ring in which one or more of the —CH— or —CH
2
— groups may be replaced by suitable heteroatom groups and which may be saturated or unsaturated and unsubstituted or substituted or be fused with further carbacyclic or heterocarbacyclic 5- or 6-membered rings which may in turn be saturated or unsaturated and substituted or unsubstituted, and
R
7
and R
8
are, independently of one another, alkyl, aryl or cycloalkyl radicals, and
R
3
, R
4
are, independently of one another, H or alkyl, aryl or cycloalkyl radicals, and
n is 1 or 2.
The bisimidines of the present invention have at least one nitrogen-nitrogen bond to at least one of the two imine nitrogens as [═N—NR
5
R
6
], where the substituents R
5
and R
6
together form a cyclic substituent.
These compounds are particularly useful as ligand systems for preparing novel, efficient catalyst systems for the polymerization or copolymerization of unsaturated compounds. These novel ligands are simple to prepare and make it possible to vary the radicals within a wide range. This system is therefore very variable and allows the ligand and complex systems to be tailored to various applications. Use of compounds of the formula (I) as ligand system makes it possible to obtain highly active catalysts for the polymerization of unsaturated compounds.
Above and in the following, alkyl radicals are generally linear or branched C
1
-C
20
-alkyl radicals, preferably C
1
-C
10
-alkyl radicals, particularly preferably C
1
-C
8
-alkyl radicals. These alkyl radicals can be substituted by heteroatoms. Suitable alkyl radicals are, for example, methyl, i-propyl, t-butyl, trifluoromethyl and trimethylsilyl radicals.
Aryl radicals are generally unsubstituted and substituted C
6
-C
20
-aryl radicals (the number of carbon atoms refers to the carbon atoms in the aryl radical), preferably C
6
-C
14
-aryl radicals, which may be unsubstituted or bear one or more substituents; very particularly preference is given to C
6
-C
10
-aryl radicals, substituted by C
1
-C
6
-alkyl radicals, e.g. 4-methylphenyl, 2,6-dimethylphenyl, 2,6-diethylphenyl, 2,6-diisopropylphenyl, 2-tert-butylphenyl, 2,6-di(tert-butyl)phenyl or 2-i-propyl-6-methylphenyl. The aryl radicals can also be substituted by heteroatoms, e.g. by F.
Cycloalkyl radicals are generally C
5
-C
8
-cycloalkyl radicals (the number of carbon atoms refers to the carbon atoms in the cycloalkyl ring) which may be unsubstituted or substituted by one or more alkyl or aryl radicals or heteroatoms. Preference is given to C
5
-C
6
-cycloalkyl radicals.
In the compounds of the present invention, R
5
and R
6
together with the N atom form a 5-, 6- or 7-membered ring in which one or more of the —CH— or —CH
2
— groups may be replaced by suitable heteroatom groups. Suitable heteroatom groups are preferably —N— or —NH— groups. Particular preference is given to from 0 to 3 —CH— or —CH
2
— groups being replaced by —N— or —NH— groups.
The 5-, 6- or 7-membered ring can be saturated or unsaturated. In the latter case, the ring may be monounsaturated or polyunsaturated. Preference is given to unsaturated 5-membered rings. For the purposes of the present invention, unsaturated rings include, in the case of the 5-membered rings, aromatic rings such as unsubstituted or substituted pyrrole radicals and derivatives thereof, which are particularly preferred.
The 5-, 6- or 7-membered ring may be unsubstituted, substituted or fused with further carbacyclic or heterocarbacyclic 5- or 6-membered rings which may in turn be saturated or unsaturated and substituted or unsubstituted.
For the purposes of the present invention, carbacyclic rings are rings whose skeleton is made up entirely of carbon. In the heterocarbacyclic rings, one or more —CH
2
— or —CH— groups are replaced by heteroatoms, preferably —NH— or —N— groups. Particular preference is given to carbacyclic rings or heterocarbacyclic rings having a nitrogen atom in the ring system.
Possible substituents in these carbacyclic and heterocarbacyclic 5- or 6-membered rings are the abovementioned alkyl, aryl or cycloalkyl radicals. The rings may bear one or more substituents. Preference is given to from 1 to 3 substituents. Furthermore, the ring systems may be orthofused or orthofused and perifused. The system is preferably orthofused, with particular preference being given to 1 or 2 phenyl radicals being fused onto the central 5- or 6-membered ring, e.g. indole, carbazole and derivatives thereof.
In a particularly preferred embodiment, the ring described by the formula NR
5
R
6
is 5-membered. Very particular preference is given to an unfused 5-membered ring, in particular a pyrrole radical or a radical derived from pyrrole, in which no, one or more, preferably from 0 to 3, particularly preferably 0 or 2, —CH— groups in the pyrrole ring may be replaced by nitrogen. Examples are the pyrrole sys

Affiliated with

Also associated with

Rating

Bisimidino compounds and the transitional metal complexes... does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Bisimidino compounds and the transitional metal complexes..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Bisimidino compounds and the transitional metal complexes... will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3323993