DE1768581C - Process for the preparation of diolefin-nickel halide complexes and their use as catalysts - Google Patents

Description

CH,

CH

CH, CH

-Ni

<7 \

CH

CH, CH

CH,

H ₇ C

Z /

Ni

\ CH,

H, C

CH - CH

CH

CH

^St.

(Z is halogen, and η is an integer of at least 1.)

The drawing shows the infrared spectrum of the butadiene-nickel bromide complex of Example 1, according to according to the method of the invention. The reaction mechanism is believed to work in the following way:

NiY, + / ι (conjugated diolefin)

Organic aluminum compound, _{Ni (conjugated} diolefin) ,, reduction

R ₁

ZCR ₂

^ ² ► NiZ (conjugated diolefin) ,,

reaction

+ 1/2-R ₁ -CCR ₁
R ₃ R ₃

(where Z is a halogen, Y is an anion or a chelating ligand, η is an integer from 1 to 3, generally 2, and R ₁ , R ₂ and R _{3 have} the meanings given above).

The nickel salts which can be used as starting material for the process according to the invention include the nickel halides such as nickel chloride, nickel bromide and nickel iodide; the dibasic nickel salts Acids such as nickel malonate and nickel phthalate; and the nickel chelate compounds of 1,3-diketone such as Nickel benzoylacetonate and nickel benzoylacetophenoate. Nickel acetylacetonate is particularly desirable.

Although all conjugated diolefins can be used, the following are particularly preferred: 1,3-butadiene, 1,3-pentadiene, isoprene, cyclopentadiene, 1,3-cyclohexadiene and 1-4 cyclooctadiene.

The organic aluminum compounds available to reduce the nickel salts are the various organic aluminum compounds with reducing properties such as trialkyl aluminum, Dialkyl aluminum alcoholate and alkali aluminum tetraalkyl, but preferred are compounds such as Triethyl aluminum, triisobutyl aluminum. Diethyl aluminum ethylate and sodium aluminum tetraethyl.

In the method according to the invention, one of the above-mentioned nickel salts is first used an organic aluminum compound, as indicated above, in the presence of one of the above, conjugated diolefin reduced.

Even if there is a special limitation - f> 5 lent the molar proportions of the reaction components does not exist in this case, the conjugated can Diolefin can usually be used in an amount of 1 to 20 moles per mole of the nickel salt. His simultaneous presence in a crowd of

2 to 5 moles is particularly useful. On the other hand, the aluminum compound can usually be in a Amount from 0.5 to 10 moles, and especially 1 to

3 moles per mole of the nickel salt can be used. This reduction reaction occurs at temperature

below carried out 50 ⁰ C, for example down to -30 ⁰ C without, preferably in the range of 0 to + 10 ⁰ C In carrying out this reduction reaction separates sometimes a part of an aluminum compound as precipitate. In such a case, the precipitate is preferably removed by filtration.

The reaction system thus obtained is then mil the above compounds of the form

ZCR ₂
R ₃

implemented.

The compounds having the formula given above include, for example

1 -Bromo-1,1 -diphenylethane,
1-chloro-U-diphenyUUhan,

1-iodine-1,1-dipheny lethane,

1 -Bromo-1,1 -diphenylpropane,

1 -Bromo-1,1 -diphenylbutane,

1 -Bromo-1,1-diphenyl-2-methylpropane,

1 -Bromo-1,1 -diphenylpentane,

2-bromo-2-phenylpropane,

2-bromo-2-phenylbutane,

S-bromo-S-phenylpentane,

l-bromo-l-cyclohexyl-l-phenylethane,

Dibromodiphenylmethane,

Tribromophenylethane and

Carbon tetrachloride.

The reaction between the reduced system and the aforementioned halogenated hydrocarbon or carbon tetrahalide described above is usually carried out below 20 ° C and preferably between -20 and 0 ⁰ C, as metallic nickel precipitates above 2O ⁰ C and also an excessive drop in the yield of the aspired organic nickel compound takes place.

A reaction time of 2 to 50 hours is usually sufficient, but a reaction time of 5 to 10 hours is preferred. Since the intended Diolefin-nickel halide complex separates out as a precipitate in the reaction system the reaction time according to the class of the reactants, the reaction temperature and other reaction conditions can be easily determined.

The compound of the formula R ¹ R ² R ³ CZ is mixed with the organic nickel compound obtained by the aforementioned method in an equimolar or over-equimolar ratio to the nickel compound, and then the reaction between these compounds is carried out.

The reaction is preferably carried out in the presence of an inert organic solvent. Such solvents include, for example, ethers such as ethyl ether, tetrahydrofuran and Dioxane; aromatic hydrocarbons and halogenated aromatic hydrocarbons such as benzene, Toluene and chlorobenzol aliphatic hydrocarbons and halogenated aliphatic hydrocarbons, such as pentane, hexane, methylene chloride, dichloroethane, Dichlorethylene and trichlorethylene; and alicyclic Hydrocarbons such as cyclopentane and cyclohexane. With regard to the separation of the By-products, the cleaning and drying of the sought-after diolefin-nickel halide complex, is that The use of ethers is particularly desirable, especially the use of ethyl ether. However, if the Reaction is conducted under such conditions that the diolefins maintain their liquid state, a special solvent does not need to be added because the diolefin itself is the solvent can serve.

The resulting diolefin-nickel halide complex usually has a reddish brown color. When the resulting diolefin-nickel halide complex completely dried, it is stable under an inert gas at room temperature. on the other hand it is unstable in oxygen and water, by which it is instantly decomposed, and in air, where the possibility there is inflammation. Therefore, all of the synthesis operations described above should be performed be carried out in an atmosphere of dry inert gas.

example 1

82 g (0.32 mol) of nickel acetylacetonate are placed in a four-necked flask with a capacity of 1 liter, which has previously been thoroughly dried and flushed with argon, and suspended ^{in 500 cm 3 of dry ethyl ether.} After cooling the suspension to -20 ⁰ C., it dissolves 85 g of dry butadiene. 114 cm ³ (0.76 mol) of diethyl aluminum ethylate are then added and the mixture is kept at 0 to 10 ° C. with an ice bath. The reaction is allowed to proceed for a few hours, the color of the suspension changing from green to yellow and then to red passes over, and the reaction is completed when the unreacted nickel acetylacetonate is drawn off. The precipitate of the aluminum compounds is removed by filtration, and the resulting reddish-brown filtrate is used in the next reaction.

200 cm ^{3 of} filtrate (nickel content 0.089 mol) are ^{cooled to below - 40 0} C, and then 170 cm ^{3 of} a solution of 1,1 -diphenyl-1-bromoethane in hexane (content of 1,1-diphenyl-1-bromoethane0, 089 mol), after which the mixture is kept at -10 to -5 ° C for 5.5 hours with stirring. The reddish brown precipitate is separated off by filtration at a low temperature, washed three times with ethyl ether and then dried in vacuo, 19.7 g (yield 99%) of the desired product being obtained. Its elemental analysis values are Ni: Br: C: H = 1.06: 1.04: 8: 11.90, this corresponds to NiBrC ₈ Hi ₂ . This product decomposed at 120 ^c C ± 5 C. Its infrared absorption spectrum is shown in the drawing. No absorption of acethylacetonate (1250, 1300, 1370, 1410, 1613 and 1710 cm " ¹ ) can be recorded, a trans double bond (967 cm"') is present and its ESR spectrum shows that it has paramagnetism .

Example 2

Example 1 is repeated using 2-bromo-2-phenylpropane instead of 1,1-diphenyl-1-bromoethane. The elemental analysis values of the product are Ni: Br: C: H = 1.03: 1.07: 8: 11.90. and according to its coloration, configuration, and infrared absorption spectrum, it had the same structure like that obtained in Example 1.

Example3

Nickel chloride is used instead of nickel acetylacetonate, and an ethereal solution of reduced nickel, which was synthesized as in Example 1, is reacted in an equimolar amount with an ethereal solution of 2.05 g of dichlorodiphenylethane. The reaction begins in the region of - 2.0 ° C and a brown precipitate forms. Is obtained by filtering at low temperature, washing and drying, 1.7 g of butadiene nickel chloride complex, the decomposition temperature is 113 ° C ± 5 ⁰

Example 4

The solution of reduced nickel, which was prepared as in Example 1, becomes an essential Solution of carbon tetrabromide added at 78 "C. After the removal of the black and white

brown precipitate, the reaction is carried out at -40 to -30 ° C, and a brown precipitate is obtained Precipitation. This is separated off and dried. It's the same as the butadiene nickel bromide complex, obtained in Example 1.

Example 5

3.65 g of purified Trichlorbromäthan be dissolved in about 100 cm ³ of ethyl ether, followed by cooling to - 78 ⁰ C follows. To this solution are added 41.2 cm ^{3 of} a solution of reduced nickel, which was prepared as in Example 1 (in an equimolar amount with respect to nickel). After performing the reaction at below -55 C for about 15 hours, the precipitate is separated by filtration, and reacting at - 20 ⁰ C, an orange

io colored precipitate is obtained, which is separated off by filtration, followed by washing with ether and drying in vacuo. This precipitate is the same as the butadiene-nickel bromide complex obtained in Example 1. It was obtained in an amount of 2.35 g (yield 67%). Its decomposition temperature is 110 ° ± 5 ° C.

Examples 6 to 10

Following the procedure of Example 1, nickel acetylacetonate is made with triethylaluminum in the presence reduced by butadiene, on its ethereal solution various halogenated hydrocarbons to act reach. The results obtained are shown in Table 1 below.

table example

6th
7th
8th
9
10

Halogenated hydrocarbon

2-bromo-2-phenylbutane

2-bromo-2-phenylpentane

1 -Bromo-1 -cyclohexyl-1-phenylethane

2-bromo-2-naphthylpropane

2-chloro-2-tolylpropane

temperature time yield C. Hours. % -10 5 10 57 -10 5 10 32 -5-0 10 13th 0-5 15th 12th -20 10 20th '7

B ei s ρ i e 1 11

After suspending 2.25 g of nickel acetylacetonate in 50 cm ^{3 of} ethyl ether, 4.36 cm ^{3 of} 1,3-pentadiene are added. 2.65 cm ^{3 of} diethyl aluminum ethylate are then added at - 25 ° C. If this mixture is held at 3 to 5 ° C for about 1 hour, it will turn into a dark brown liquid. An equimolar amount of a 1-bromo-1-diphenylethane solution in hexane is then added. When the mixture is ^{kept at -10 to 0 °} C. for about 8 hours, a brown precipitate is obtained. This is a nickel-pentadiene complex of the same type as that of Example 1, its elemental analysis values _{correspond to C 10} H _{16 NiBr.} The complex is obtained in an amount of 1.14 g (yield 53%), and its decomposition temperature is 116 ° ± 5 ° C.

Example 12

1.07 g (4.2 mmol) of nickel acetylacetonate are suspended ^{in 50 cm 3 of ethyl ether.} After 2.4 g (45 mmol) butadiene was dissolved therein, it is 1.37 g (6.6 mmol) Natriumaluminiumtetraäthyl at - 20 ⁰ C added. The mixture is then held at 3 to 5 ° C. When it becomes a reddish brown solution, it is reacted with an equimolar amount of 1,1-diphenyl-1-bromoethane for 5 hours at -5 ° C. The reddish brown precipitate is separated off by filtration, washed and dried. 0.92 g (yield 89%) of the product are obtained. It was found from its infrared absorption spectrum that the product is the same complex as that obtained in Example 1.

Example 13

2 g (7.8 mmol) of nickel acetylacetonate are ^{suspended in 50 cm 3 of} ethyl ether, whereupon 1.5 g (22 mmol) of isoprene and, at - 20 = C, 1.6 g (8.1 mmol) of triisobutylaluminum are added. The mixture is then kept at 3 to 5 ^° C. After adding an equimolar amount of 2-chloro-2-phenylpropane, the reaction is carried out for 5 hours at -15 to 50 ° C., a brown precipitate being formed. This is separated off by filtration, washed and dried, and 1.5 g of an isoprene-nickel chloride complex, the decomposition temperature of which is 115 ° ± 5 ° C., are obtained.

Example 14

1.9 g (7.6 mmol) of nickel acetylacetonate are suspended in ethyl ether ³ 50 cm, whereupon 3.1 cm ³ cyclopentadiene and 3,1 cm ³ Diäthylaluminiumäthylat adds If this mixture is maintained at 0 to 10 ⁰ C, it becomes a reddish brown solution. After the suspension of the nickel acetylacetonate has completely reacted, 14.3 cm ^{3 of} a solution of 1,1-diphenyl-1-bromoethane in hexane (18.9 mmol / cm ³ ) are added, and the reaction is 10 hours at -10 to 0 ⁰ C carried out, whereupon treatment as in Example 1 follows. 0.3 g of a brown precipitate is obtained, which has a decomposition temperature of 108 ° ± 5 ° C.

Examples 15-18

Example 1 is carried out using nickel compounds of various classes in place of Nickel acetylacetonate repeatedly. The results obtained are shown in Table II below.

Table II

10

example

Nickel compound

Nickel bromide
Nickel acetate
Nickel oxalate
Nickel oxalate

1.9

4.1 2.1

Aluminum coating

Triäthyhiliiniinium Triethyl aluminum triethyl aluminum triethyl aluminum

solvent temperature time
SlJ. Out-
todayc C. G Clilorbcnzol 5 to 15 25th 0.3 Ethyl ether 10 to 15 40 0.3 Chlorobenzene 0 to 5 40 0.2 Tetrahydrofuran 0 to 5 40 0.8

The following examples illustrate the preparation of catalysts used in oligomerization of olefins can be used as one of the constituent components of the catalyst the diolefin-nickel halide complexes used as are available in Examples 1-18 are. The oligomerization of olefins using the catalysts prepared in this way is also possible illustrated.

Example 19

0.277 g (1.24 mmol) of the butadiene-nickel bromide complex, which is obtained in Example 1, is dissolved in 100 cm ^{3 of} chlorobenzene. After adding 1.2 mmol of aluminum tribromide at below -30'C. at -IC ethylene is blown in. 57.9 g of ethylene are converted and the effectiveness of the catalyst is exhausted in about 30 minutes. The product consists of 32.7 g (56.5%) dimers and 18.7 g (32.3%) trimers. The results of analysis by gas chromatography show that, of the dimers, 3.1% are butene-1, 77.3% are trans-butene-2, and 19.6% are cis-butene-2; of the trimers, 47% are trans-3-methylpentene-2 and 16% are trans-hexene-2.

Examples 20 to 25

If, in Example 19, 1 equivalent of aluminum tribromide and 1 equivalent of a compound of an element of main group V, which are shown below in Table III, are used with butadiene-nickel bromide and the polymerization reaction is carried out at -20 to 10 ^° C. for 20 minutes, then achieved the results shown in Table III.

Table III

example

20th

21

Menu on
Nickel complex
catalyst
111M oil

2.45
2.81
3.10

Melallorganic
connection

product

Dimer "
G

70 55 50

TrimeO

Triphenylarsine
Triphenylstibine
Triphenyl bismuth
The experiments are carried out in the same manner except that the compounds of the elements of main group V are changed by '· the reactions are carried out for 30 to 50 minutes at a temperature of -30 to -1O ⁰ C. Ok results are shown in Table IV below!

Table IV example

23 24 25th

Butadiene nickel bromide

complex

mmol

2.02
2.41
2.03

AlBr,
mmol

2.02
2.41
3.55

Organometallic compound
mmol

Triphenylphosphine 2.02

Triisopropylphosphine 2.41
Triphenyl phosphite 2.03

product Dimers TrimcK G 354 60 48 G 44 70 6th

Examples 26 to 34

The polymerization of propylene is carried out for 10 minutes at atmospheric pressure in chlorobenzene, being a combination of the complex prepared in Example 1 and an equimolar amount of one Aluminum halide is used. The results obtained are shown in Table V below.

Table V

example crowd
catalyst Aluminum connection Reaction temperature Product*) mmol ⁰ C G 26th 0.94 Aluminum trichloride -35 26 10 27 2.24 Aluminum tribromide -40 ~ -27 19th 28 5.33 Aluminum triiodide -39 ~ -29 18th 29 2.92 Diethyl aluminum chloride -35 ~ -30 7th 30th 2.41 Ethyl aluminum dichloride -35 15 6th 3! 2.42 Diethyl aluminum ethylate -47 37 6th

* \ Total amount of dimers and trimers.

If other solvents are used in place of chlorobenzene in Example 26, those in the following are achieved Results shown in Table VI.

Table Vl

example
32

33
34
35

crowd
catalyst

mmol

2.57
2.38
2.05
2.08

solvent

Cyclohexane

Pentane

Tetrachlorethylene hexane

icaktionslempcralur C. Product*) ~ -28 e -40 25th 13th -30 15th 8th -30 ~ -20 18th -30 9

*) Total amount of dimers and trimers. Comparative experiments

To compare the diolefin-nickel halide complexes prepared according to the invention with those from German Auslegeschrift 1 194 417 known n-ally! - nickel halides in the oligomerization of olefins, the following experiments were carried out:

1. The procedure according to Example 27 was followed, with the butadiene-nickel bromide complex being used instead as a catalyst rr-cinnamyl nickel bromide (Example 4 of German Auslegeschrift 1 194 417) was used. The product yield was 15 g compared to 19 g according to Example 27 of the application description.

2. The procedure of Example 23 was followed, but instead of the butadiene-nickel bromide complex as a catalyst.-τ-allyl nickel bromide (Example 1 of the German Auslegeschrift 1 194 417) was used. The yield of dimer was 227 g, K7 g of trimer being obtained at the same time. The comparison with Example 23 shows the significantly higher yield of dimer and the better selectivity with regard to the production of dimers in the

application-restricted procedure.

3. 1.89 mmol of each of the butadiene-nickel bromide complex, AlBr ₃ and triphenylphosphine were dissolved in 100 ml of chlorobenzene. Propylene was then bubbled into the solution at a temperature of -25 to -18 ° C for 40 minutes. 354 g of an oligomer were obtained, 92.4% of which were dimers.

The same procedure was repeated, but using n-allyl nickel bromide as the catalyst of the complex described above were used. 320 g of oligomer were obtained, of which 89.0% were dimers.

As can be seen, in the process according to the invention, the yield and selectivity were in comparison with the use of the well-known.-i-allyl nickel halides considerably higher.

1 sheet of drawings

Claims (2)

Patent claims: 1. Process for the preparation of diolefin-nickel halide complexes, characterized in that the solution of a complex obtained by reducing a nickel salt obtained with an alkyl aluminum compound in the presence of a conjugated diolefin with a compound of the formula R ¹ R ² R ³ CZ reacted, in which Z is a halogen, R ¹ , R ² and R ^{3 are} a halogen, alkyl or aryl radical, where R ¹ , R and R ^{3 may} not be aryl radicals at the same time. 2. Use of the compounds prepared according to claim 1 as catalysts or catalyst components For oligomerization reactions of olefins. The invention relates to a process for the preparation of diolefin-nickel halide complexes, which are useful in catalyst systems for the oligomerization of olefins. The process of the invention for making the diolefin-nickel halide complexes is thereby characterized in that the solution of a complex obtained by reducing a nickel salt (inorganic or organic salts of nickel, including nickel chelate compounds) with an alkyl aluminum compound in the presence of a conjugated diolefin with a compound the formula 45 reacted, in which Z is a halogen, R ₁ , R ₂ and R _{3 are} a halogen, alkyl or aryl radical, where R ₁ , R ₂ and R _{3 may} not be aryl radicals at the same time. The diolefin-nickel halide complexes obtained according to the invention are very effective as a component of a catalyst for oligomerization of olefins in combination with 0.5 to -30 moles, preferably 1 to 10 moles, per mole of this complex, of at least one aluminum halide, such as aluminum trichloride, Aluminum tribromide, or organic aluminum halides such as diethyl aluminum chloride and ethyl aluminum dichloride, and further optionally no more than 10 moles per mole thereof Complex of an organic compound of phosphorus, arsenic, antimony or bismuth, for example Triethylphosphine, triisopropylphosphine, tri-u-butylphosphine, tricyclohexylphosphine, triphenylphosphine, Triphenyl phosphite, tricresyl phosphite, tri-o-diphenyl phosphite, Diphenylphenoxyphosphine, diphenyl-p-cresylphosphine, triphenylarsine, triphenylstibine and triphenyl bismuth. This catalyst shows improved properties when used in the preparation of lower olefin polymers is used, for example for the production of butene, hexene and methyl pillars from ethylene or Hexene, methylpentene and dimethylbutene from propylene. The aforementioned catalyst for oligomerization of olefins, which are the diolefin-nickel halide complexes obtained by the process according to the invention used has the following advantages: Because it has an improved oligomerization efficiency possesses, it improves the yield of the desired oligomer; because it has improved stability it improves the reproducibility of the oligomerization reaction; because it has an improved selectivity, it is effective to narrow the molecular distribution range of the aimed oligomer; because If the oligomerization has a shortened exposure time, the reaction can be carried out with advantage and the preparation of the catalyst is easy. So far there are processes for the production of.-Τ-allyl metal compounds and processes for the oligomerization of olefins using such compounds known from British patents 1,058,679 and 1,058,680. The British patent specification 1 058 679 describes a process for the preparation of.-R-allyl metal compounds of .-r-allyl-QX-type (where Q is a transition metal and X denotes an anionic radical), which is characterized in that an.-I-allyl metal compound of the .τ-allyl-Q-type, such as bis -.- r-allylnickel and bis-.T-cyclooctadiene nickel (O), with an acidic Compound of the formula HX (where X is an anionic radical), for example with hydrogen halides implements. In this proposal, a zero-valent.-T-allyl metal compound, such as bis-.7-allyl nickel- (0] and bis -.- r-Cyclooctadiennickel- (O), as a starting material used. Such a starting material is obtained by an intricate method, which involves several stages and therefore the process of this British patent is inadequate low yields and high cost of the starting material. Furthermore, the diolefin-nickel-halogen compounds, obtained according to the method of British Patent 1,058,679 more unstable and difficult to handle compared to the diolefin-nickel halide compounds, which can be obtained by the method according to the invention, in which a nickel salt is used as the starting material is used. Although it has been confirmed that the reaction product obtained by the process of the present invention is a complex of a diolefin with a nickel halide (see Example 1), then dei The reaction mechanism and the structure of the complex obtained are not yet established. As a result, Elemental analysis, molecular weight, bulk volume, the hydrogenation reaction, the decomposition reaction using iodine, the reaction with triphenylphosphine and the well-known constitution of the Co and Rh complexes, it is assumed that; the structure of the complex (when butadiene has been used as the conjugated olefin) is as follows