BRPI1005977A2 - chromium and nickel catalysts for oligomerization reactions and process for obtaining alpha olefins using such catalysts - Google Patents

Abstract

CHROME AND NICKEL CATALYSTS FOR OLIGOMERIZATION REACTIONS AND PROCESS FOR OBTAINING ALPHA-OLEFINS USING SUCH CATALYSTS. The present invention relates to the synthesis of catalytic precursors and the use of said catalytic precursors in ethylene oligomerization reactions for the selective production of alpha-olefins. More specifically, it refers to the preparation and use of coordination compounds that contain polyidentated binders, which comprise compounds based on transition metals of groups 6 and 10, in particular the metals chromium (III) and nickel (II). Said catalytic precursors have a high catalytic activity and a high selectivity for the production of alpha-olefins.

Description

Chromium and nickel catalysts for oligomerization reactions and process for obtaining alpha-olefins using such catalysts

FIELD OF INVENTION

The present invention relates to the synthesis of catalytic precursors and the use of said catalytic precursors in ethylene oligomerization reactions for the selective production of alpha olefins. More specifically, the present invention relates to the synthesis of polyidentate coordinating compounds which contain transition metals of groups 6 and 10 of the Periodic Table of Chemicals, and the use of such compounds as catalysts in olefin oligomerization, particularly in dimerization. and ethylene trimerization for selective alpha olefin production.

BACKGROUND OF THE INVENTION

The alpha olefins of major industrial interest are linear hydrocarbons of 4 to 20 carbon atoms. In oligomerization the carbon chains join through the carbon atoms located at the end of the chains in the alpha position by means of double bonds. They are used not only in the production of surfactants and synthetic lubricants, but also as co-monomers in the production of olefin polymers (polyolefins). In the last decades, catalytic systems with higher activity and better selectivity have been developed to allow more economical oligomerization and / or trimerization processes of olefins.

Catalytic ethylene oligomerization systems for the production of higher alpha olefins are often described in the state of the art employing complex titanium, nickel and, to a lesser extent, zirconium compounds.

GB 1294214 describes a catalytic system using a titanium complex. Also described herein is a suitable process for producing a catalyst for obtaining olefins of 8 to 20 carbon atoms by means of ethylene oligomerization.

Another cataitic oligomerization system is described in patent document WO 2005/092821. This document discloses a process using nickel, iron or cobalt catalysts for the production of 4 to 12 carbon atoms olefins. However, titanium, nickel and zirconium catalysts most often result in products containing a wide range of alpha olefins, due to the low catalytic selectivity for olefin production by ethylene oligomerization.

The activity and selectivity of catalytic systems are a function of the nature of the ligands used, the combination of the ligands and the catalyst / cocatalyst ratio, such as EtnAICI3.n or methylaluminoxane.

Catalytic systems capable of selectively oligomerizing ethylene include chromium-based catalytic systems.

Chromium catalysts have been widely used in a variety of olefin polymerization processes, such as the production of polyethylene or ethylene and hexene copolymers. Thus, said chromium-based catalytic systems have been applied in the selective production of alpha olefins. It is known in the art to use a chrome catalyst for ethylene trimerization based on a tridentate ligand which contains nitrogen and sulfur atoms as donor groups.

US 2005/131262 describes a high selectivity catalytic system, the purpose of which is to facilitate the production of 1-hexene in order to avoid the coproduction of significant quantities of polyethylene. Such catalytic system comprises a combination of multidentified ligand heteroatoms useful for catalytic olefin oligomerization which includes as ligand at least three heteroatoms, of which at least one is a sulfur atom. Additionally, the linking heteroatoms may also be additional sulfur atoms and at least one nitrogen or phosphorus atom.

Although alternative ethylene oligomerization catalytic systems are still widely investigated, there is still a lack of catalytic systems for more selective, higher activity and high throughput ethylene oligomerization and / or trimerization. Thus, the development of catalytic systems with co-catalysts more selective to the most desirable alpha olefin fraction in the range of 6 to 10 carbon atoms has become quite attractive.

SUMMARY OF THE INVENTION

The present invention relates to the synthesis of catalytic precursors and the process for the selective production of alpha olefins, in which the catalysts obtained with such precursors are used in oligomerization reactions, particularly ethylene dimerization and trimerization.

More specifically, the present invention relates to the synthesis and use of group 6 transition metal-based polyidentated coordination compounds of the Periodic Table, such as chromium (III), or of group 10, such as nickel (II) .

That is, the present invention teaches the preparation of Cr-based compounds from the reaction between tridentate nitrogen binders and a Cr (THF) 3Cl3 adduct equivalent compound in a solution of tetrahydrofuran (THF) for 3 hours under argon atmosphere, and the preparation of Ni-based compounds from the reaction between tridentate nitrogen binders and NiCl2.6H20 in THF for 24 hours.

Additionally, the present invention teaches the preparation of catalytic systems which use catalysts and cocatalysts in olefin oligomerization reactions. These systems have a high catalytic activity and a high selectivity for the production of alpha olefins. DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to the synthesis of catalytic precursors. Additionally, the present invention relates to the use of said catalytic precursors in ethylene oligomerization reactions in a process for the selective production of alpha olefins.

More specifically, said precursors are polyidentate coordinating compounds, which comprise group 6 transition metal-based compounds of the Periodic Table, particularly chromium (III) metal, and group 10 transition metal-based compounds, particularly nickel metal (II).

Catalysts for the ethylene oligomerization reaction for alpha olefin production obtained according to the present invention comprise transition metal compounds and are represented by the formula LMX3 or LMX2, where: "M" is a selected transition metal group 6 or 10 of the Periodic Table of the chemical elements and their oxidation state may range from +2 to +6. "X" is an anion; "L" is a ligand according to the structure represented by Formula 1, also represented by the formula E [(CH2) (Pz)] 2R4, where: "E" is an oxygen, nitrogen or sulfur atom, whether or not bound to one or two groups "Pz" and one radical R4.

Each of the "Pz" groups comprises a pyrazolyl ring with a nitrogen atom as heteroatom. For the inventor of the present invention, the two "Pz" groups may be the same or distinct. The radicals R1, R2 and R3 represent hydrogen atoms or hydrocarbyl radicals located respectively at positions 3, 4 and 5 of the pyrazolyl ring.

In accordance with the present invention, at least one of the positions 3, 4 and 5 of the pyrazolyl ring must be filled with a hydrocarbyl radical. These hydrocarbyl radicals may be the same or distinct from each other. However, if only one or two of these positions are filled by this type of radical, the unfilled position must contain either a hydrogen atom or a hydrocarbon radical having a number of carbon atoms in the C1-C3 range.

The radicals R1, R2, R3 and R4 may be of the following types: a C1-C20 aliphatic hydrocarbyl radical; a C1-C20 aliphatic hydrocarbyl radical which is substituted with at least one C6-C14 aromatic radical; an unsubstituted C6 -C20 aromatic hydrocarbyl radical; a C6 -C20 aromatic hydrocarbyl radical which is substituted with at least one C1-C10 alkyl radical.

Illustrative but not restrictive examples of "M" transition metals that may be used by this invention are chromium, molybdenum and tungsten of group 6 of the Periodic Table and nickel and palladium of group 10 of table Periodic.

Illustrative, but not restrictive, examples of "X" anions that may be used in accordance with this invention are chloride, bromide, fluoride and alkyl derivatives such as methyl and ethyl. These binders may be the same or distinct from each other.

As illustrative but not restrictive examples of groups R1, R2, R3, located respectively at positions 3, 4 and 5 of the pyrazolyl ring, and R4 may be cited n-butyl, iso-butyl, tert-butyl, iso-radicals. pentyl, neo-pentyl, phenyl, benzyl, cumenyl and mesityl.

Optionally the catalytic composition to be used in the oligomerization reaction may comprise one or more types of co-catalysts, whether or not combined, such as alkylaluminum, hydrocarbylaluminoxane or borane co-catalysts, the latter derivative of B (C6F5) 3 Preferred examples of alkylaluminiums include trialkylaluminum and bisalkylaluminum derivatives with C1-C8 alkyl groups such as trimethylaluminum, triisobutylaluminum, dimethylaluminum chloride and diethylaluminum chloride. Preferably used hydrocarbylaluminoxanes are alkylaluminoxanes, arylaluminoxanes and alkylaryluminoxanes with C1-C4 alkyl groups such as modified methylaluminoxane and methylaluminoxane. Preferred examples of boranes include B (C6F5) 3 and its derivatives [(phenyl) 3C] [B (C6F5) 4], [(methyl) 3HN] [B (C6F5) 4], [(ethyl ) 3HN] [B (C6F5) 4] and [(phenyl) 3HN] [B (C6F5) 4].

When using aluminum based co-catalysts, the ratio adopted between co-catalyst and catalyst is a molar ratio which is between 1: 1 and 1: 10,000, preferably between 1:50 and 1: 5,000 and more preferably between 1 : 200 and 1: 2,000. This molar relationship is defined by the molar relationship between aluminum and metals of groups 4, 5 or 10 of the Periodic Table. When boron-based co-catalysts are used the molar ratio is 1: 1 and is defined by the molar relationship between boron and metals of groups 4 or 5 of the Periodic Table.

The catalysts of the present invention may be used in liquid phase or gas phase oligomerization processes. Said catalysts may participate in reactions solubilized in the reaction medium, dispersed in organoaluminate ionic liquid or in suspension, when supported on a suitable support. Suitable carriers for use in the present invention include silica, magnesium chloride and alumina. The oligomerization reaction is conducted under conditions normally employed with other types of catalysts. The temperature ranges from -10 ° C to 150 ° C, preferably from 70 ° C to 90 ° C for group 6 transition metals and preferably from 20 ° C to 60 ° C for group 10 transition metals. such as temperature, oligomerization pressure and reaction time also depend on the type and conditions of processes employed and the monomers used. Absolute pressure ranges from 1 bar to 140 bar and residence time ranges from 1 to 240 minutes. The monomers used in the reaction of the present invention comprise one or more olefins having a number of carbon atoms ranging from 2 to 12 atoms.

The single phase system of the present invention uses as polar or polar compounds, whether liquid or gaseous compounds. Examples of such solvents are apolar alkanes such as hexane, heptane and cyclohexane or polar alkanes such as toluene, chlorobenzene and dichloromethane.

The catalytic precursors employed in the present invention containing Cr are obtained from the reaction between tridentate nitrogen binders and a compound equivalent to the Cr (THF) 3Cl3 adduct, the structure of which is shown in Formula 2, in a solvent such as a solution of tetrahydrofuran (THF) under an argon atmosphere.

<formula> formula see original document page 8 </formula>

FORMULA 2

After the reaction of said nitrogenous ligands with the THF tetrahydrofuran solution, the THF solvent is evaporated under vacuum and the final catalysts are obtained: Cr (DMPMNBz) CI3 (Formula 3), Cr (DMPMNBu) CI3 (Formula 4) and Cr (DMPMS) CI3 (Formula 5).

<formula> formula see original document page 8 </formula>

FORMULA 3

<formula> formula see original document page 8 </formula>

FORMULA 4

<formula> formula see original document page 8 </formula>

The catalytic precursors employed in the present invention which contain Ni are obtained from the reaction between tridentate nitrogen binders and a compound equivalent to the NiCl2.6H20 adduct in a solvent such as a tetrahydrofuran (THF) solution. under argon atmosphere.

Examples of tridentate nitrogen binders include:

- bis [((3,5-dimethyl-1-pyrazolyl) methyl)] benzylamine (DMPMNBz);

- bis [((3,5-dimethyl-1-pyrazolyl) methyl)] butylamine (DMPMNBu);

- bis [((3,5-dimethyl-1-pyrazolyl) methyl)] sulfide (DMPMS);

- bis [((3-phenyl-1-pyrazolyl) methyl)] sulfide (FPMS).

After the reaction between said nitrogenous binders and the THF solution, the solvent is evaporated in vacuo and the final catalysts of general formula are obtained:

Ni (DMPMNBz) CI2 (Formula 6), Ni (DMPMNBu) CI2 (Formula 7), Ni (DMPMS) CI2 (Formula 8) and Ni (FPMS) CI2 (Formula 9).

<formula> formula see original document page 9 </formula>

FORMULA 6

<formula> formula see original document page 9 </formula>

FORMULA 7

<formula> formula see original document page 9 </formula>

FORMULA 8

<formula> formula see original document page 9 </formula>

FORMULA 9

Additionally, the present invention describes catalytic systems which utilize said catalysts in the presence of a cocatalyst in olefin oligomerization reactions. These catalytic systems present catalytic activity and selectivity for the production of alpha olefins superior to those observed in traditional equivalent systems.

Oligomerization reactions are performed in one step in a steel reactor, which is equipped with a mechanical stirrer and inlet that allows continuous injection of ethylene. The reaction temperature is controlled by a thermostatic bath. After this stage, the products are separated and later characterized.

In the present embodiment, the technique used for characterization of the ethylene oligomerization reaction products was the chromatography technique.

After characterization of the products by chromatography, a final product composed of a variety of olefins is observed, which comprise carbon chains in the range of 4 to 12 carbon atoms (C4 to C12 +). However, there is an almost exclusive predominance of alpha olefins as a product of the oligomerization reaction.

Some adjustments must be made to the operating conditions of the reaction system, such as changes in ethylene injection pressure, reaction system temperature, Al / M molar ratio (M = group 6 or 10 transition metal) and in the concentration of the solvent used in order to increase the yield of higher value-added products, ie products with a larger carbon chain, such as carbon chains in the range of 6 to 10 carbon atoms, and also with a higher alpha olefin content.

The invention will be set forth in more detail below by way of examples which are not to be construed as limiting the scope of the invention.

EXAMPLE 1:

Iiaant synthesis

The following Ligands were prepared according to the methodology known in the art (procedures described in MR Malachowski, MG Davidson Inorg. Chim. Acta, 162, (1989), 199 and R. Touzani, A. Ramdani, T. Ben Hadda S. El Kadiri, O. Maury, H. Le Bozec, PH Dixneuf Synth Commun., 31 (2001), 1315):

Bis [((3,5-dimethyl-1-pyrazolyl) methyl)] benzylamine (DMPMNBz);

Bis [((3,5-dimethyl-1-pyrazolyl) methyl)] butylamine (DMPMNBu).

Two binders of the present invention were prepared under an inert argon atmosphere according to the following steps:

(A) Bis [((3,5-dimethyl-1-pyrazolyl) methyl)] sulfide linker (DMPMS):

1) refluxing for 3 hours a 50% aqueous solution of ethanol of 1- (2-chloromethyl) -3,5-dimethylpyrazole (4.93 g, 34.1 mmol) and sodium hydroxide (1.36 g, 34.1 mmol) with Na 2 S 9H 2 O (5.13 g, 21.4 mmol);

2) cool to room temperature;

3) evaporate under reduced pressure;

4) add water and extract the product with dichloromethane;

5) dry with anhydrous Na 2 SO 4;

6) evaporate to a colorless oil.

The yield was 38%.

(B) Bis [((3-phenyl-1-pyrazolyl) methyl)] sulfide linker (FPMS):

1) maintain at 120 ° C for 48 hours a mixture of 3-phenylpyrazole (6.34 g, 44 mmol) and paraformaldehyde (1.32 g, 44 mmol) in a Fischer-Porter reactor;

2) remove 1- (Hydroxymethyl) -3-phenylpyrazole from the upper wall of the Fischer-Porter reactor (0.54 g, 7.0%);

3) add a solution of thionyl chloride (0.45 mL, 6.2 mmol) in CHCl 3 (15 mL) dropwise in a solution of 1- (hydroxymethyl) -3-phenylpyrazole (0.54 g, 3.1 mmol) in CHCl 3 (25 mL) at 0 ° C and then refluxing for 4 hours at 60 ° C the resulting solution;

4) evaporate the solvent and recrystallize from ethanol with an ether monolayer to give 1- (2-chloromethyl) -3,5-dimethylpyrazole (white crystals) in 84% yield; 5) refluxing for 3 hours a 50% aqueous ethanol solution of 1- (2-chloromethyl) -3,5-dimethylpyrazole (4.93 g, 34.1 mmol) and sodium hydroxide (1.36 g, 34.1 mmol) with Na 2 S 9H 2 O (5.13 g, 21.4 mmol);

6) cool to room temperature;

7) evaporate under reduced pressure;

8) add water and extract the product with dichloromethane;

9) dry with anhydrous Na 2 SO 4;

10) evaporate to a colorless oil.

The yield was 54%.

EXAMPLE 2:

Catalyst Synthesis Cr (DMPMNBz) Cl3 (1)

Catalyst Cr (DMPMNBz) CI3 was synthesized according to the following steps:

1) preparing a 0.243g solution of [Cr (THF) 3 Cl3] (0.65 mmol) in THF;

2) adding a solution with 0.231 g DMPMNBz (0.71 mmol) in THF;

3) stirring the resulting mixture on a shaker plate for 3 hours;

4) evaporate the solvent under vacuum to give the formation of a light green Cr (DMPMNBz) CI3 compound.

The mass of the light green Cr (DMPMNBz) CI3 compound was 0.270 g and the yield of the Cr (DMPMNBz) CI3 catalyst synthesis reaction was 87%.

The calculated C 19 H 25 N 5 CrCl 3 mass was: C 47.37; H 5.23; N 14.54. Found value: C 47.10; H 5.02; N 14.17.

HRMS-ESI [M-Cl] + analysis was performed and the mass calculated for C19H25N535Cl258Cr was 445.08921 and the value found was 445.08805.

EXAMPLE 3:

Catalyst Synthesis Cr (DMPMNBu) CU (2)

The synthesis of Cr (DMPMNBu) CI3 catalyst was performed according to the following steps:

1) preparing a solution with 0.299 g of [Cr (THF) 3 Cl3] (0.80 mmol) in THF;

2) adding a solution with 0.231 g of DMPMNBu (0.79 mmol) in THF;

3) stirring the resulting mixture on a shaker plate for about 3 hours;

4) evaporate the solvent under vacuum to give the formation of a light green compound, Cr (DMPMNBu) CI3.

The mass of green compound Cr (DMPMNBu) CI3 was 0.243 g and the yield of the synthesis reaction of Cr (DMPMNBz) CI3 catalyst was 68%.

The calculated C16 H27 N5 CrCl3 mass was: C 42.92; H 6.08; N 15.64. Found value: C 42.21; H 5.66; N 15.01.

HRMS-ESI [M-CI] + analysis was performed and the mass calculated for C16H27N535CI258Cr was 411.10486 and the value found was 411.1050.

EXAMPLE 4:

Catalyst Synthesis Cr (DMPMS) Ck (3)

Catalyst Cr (DMPMS) CI3 synthesis was performed according to the following steps:

1) preparing a solution with 0.15 g of [Cr (THF) 3 Cl3] (0.30 mmol) in THF;

2) adding a solution with 0.085 g DMPMS (0.34 mmol) in THF;

3) stirring the resulting mixture on a shaker plate for 3 hours;

4) evaporate the solvent under vacuum to result in the formation of a light green compound, Cr (DMPMS) CI3.

The mass of green compound Cr (DMPMS) CI3 was 0.243g and the yield of the synthesis reaction of Cr (DMPMS) CI3 catalyst was 68%.

The calculated mass of C 12 H 18 N 4 CrCl 3 S was: C 35.26; H 4.44; N 13.71. Found value: C 35.11; H 4.21; N 13.99.

HRMS-ESI [M-CI] + analysis was performed and the mass calculated for C12H18N435CI258CrS was 406.97229 and the value found was 406.97115.

EXAMPLE 5:

Synthesis of the catalyst Ni (DMPMNBz) CI? (4)

The synthesis of Ni (DMPMNBz) CI2 catalyst was performed according to the following steps:

1) prepare a solution with 0.13 g NiCl2.6H20 (0.55 mmol) in THF;

2) adding a solution with 0.20 g DMPMNBz (0.62 mmol) in 10 mL THF;

3) stirring the resulting mixture on a shaker plate for 24 hours;

4) evaporate the solvent under vacuum;

5) wash with dry ether 3 times, resulting in formation of green compound Ni (DMPMNBz) CI2.

The mass of green compound Ni (DMPMNBz) CI2 was 0.20 g and the yield of the synthesis reaction of catalyst Ni (DMPMNBz) CI2 was 75%.

The calculated mass of C19 H25 Cl2 N5 N1 H2 O was: C, 46.66; H 5.98; N, 14.32. Found: C, 46.51; H, 5.90; N1 14.07.

HRMS-ESI [M-CI] + analysis was performed and the mass calculated for C19H25N535CI58Ni was 416.11520 and the value found was 416.1144.

EXAMPLE 6:

Synthesis of Ni (DMPMNBu) CI catalyst, (5)

The synthesis of Ni (DMPMNBu) CI2 catalyst was performed according to the following steps:

1) prepare a solution with 0.08 g NiCl2.6H20 (0.35 mmol) in THF;

2) adding a solution with 0.11 g DMPMNBu (0.38 mmol) in 10 mL THF;

3) stirring the resulting mixture on a shaker plate for 24 hours;

4) evaporate the solvent under vacuum; 5) wash with dry ether 3 times, resulting in formation of green compound, Ni (DMPMNBu) CI2.

The mass of green Ni (DMPMNBu) CI2 compound was 0.12 g and the yield of the Ni (DMPMNBu) CI2 catalyst synthesis reaction was 91%.

The calculated mass of C 16 H 27 Cl 2 N 5 N 1 O 2 H 2 O was: C, 42.23; H 6.87; N, 15.39. Found value: C, 42.04; H 6.64; N, 14.97.

HRMS-ESI [M-CI] + analysis was performed and the mass calculated for C16H27N535CI58Ni was 382.13085 and the value found was 382.1309.

EXAMPLE 7:

Ni Catalyst Synthesis (DMPMS) CI9 (6)

The synthesis of Ni catalyst (DMPMS) CI2 was performed according to the following steps:

1) prepare a solution with 0.05 g NiCl2.6H20 (0.21 mmol) in THF;

2) adding a solution with 0.05 g DMPMS (0.22 mmol) in 10 ml THF;

3) stirring the resulting solution on a shaker plate for about 24 hours;

4) evaporate the solvent under vacuum;

5) wash with dry ether 3 times, resulting in the formation of green compound Ni (DMPMS) CI2.

The mass of green compound Ni (DMPMS) CI2 was 0.14 g and the yield of Ni catalyst synthesis reaction (DMPMS) CI2 was 65%.

The calculated mass of C 12 H 18 Cl 2 N 4 N 1 S 4 H 2 O was: C, 34.65; H, 5.33; N, 13.47. Found value: C, 34.51; H, 5.12; N1 13.22.

HRMS-ESI [M-CI] + analysis was performed and the mass calculated for C12H18N435Cl58NiS was 343.02942 and the value found was 343.0291. EXAMPLE 8:

Ni catalyst synthesis (DFPMS) CI? (7)

The synthesis of Ni catalyst (DFPMS) CI2 was performed according to the following steps:

1) preparing a solution with 0.06 g NiCl2.6H20 (0.25 mmol) in THF;

2) adding a solution with 0.09 g DFPMS (0.25 mmol) in 10 mL THF;

3) stirring the resulting mixture on a shaker plate for 24 hours;

4) evaporate the solvent under vacuum;

5) wash with dry ether 3 times, resulting in the formation of green compound Ni (DFPMS) CI2.

The mass of green compound Ni (DFPMS) CI2 was 0.08 g and the yield of Ni catalyst synthesis reaction (DFPMS) CI2 was 70%.

The calculated mass of C20 H18 Cl2 N4 N1 S2 H2 O was: C, 46.91; H, 4.33; N, 10.94. Found: C, 46.72; H, 4.21; N, 10.72.

HRMS-ESI [M-CI] + analysis was performed and the mass calculated for C20H18N435CI58NiS was 439.02942 and the value found was 439.0296.

EXAMPLE 9:

Oligomerization reaction with chrome catalysts

Alpha olefins were produced in a sterile humid environment by autoclaving at a temperature of 80 ° C and an atmospheric pressure of 20 atm using a process comprising the following steps:

1) 40 ml of a solution is injected into the reactor under argon atmosphere (in the present embodiment, the solution introduced into the reactor comprises a first solution, a toluene solution and a second solution which serves as a cocatalyst, for example a solution of methylaluminoxane, ΜΑΟ, with an Al / Cr molar ratio of 300 mol / mol); 2) the ethylene oligomerization reaction system is saturated;

3) start the oligomerization reaction by adding to the reaction system 30 μητιοΙ of the catalytic precursor diluted in toluene Cr (DMPMNBz) CI3;

4) The oligomerization reaction is interrupted by depressurizing and cooling the system.

Initially, the ethylene solution is injected into the reaction system continuously so that the ethylene pressure remains constant. After approximately 15 min of development of the oligomerization reaction the reaction is stopped by depressurization and cooling of the system to -20 ° C. Thereafter an amount of cyclohexane is added to said system. Said cyclohexane solution serves as an internal standard for the reaction and the amount added must respect the proportions of the mixture. After addition of the cyclohexane solution, the oligomerization reaction product is analyzed by gas chromatography technique.

The product of the Cr (DMPMNBz) CI3 precursor oligomerization reactions obtained as described in Example 2 is a mixture of olefins, mostly alpha-olefins, which have a number of even carbons, preferably 4 to 12 olefins. carbon atoms.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 1.

EXAMPLE 10:

Oligomerization reaction with chrome catalysts

The oligomerization reaction was analogous to that described in Example 9 except that the temperature remained at 100 ° C. The product of oligomerization reactions with the precursor Cr (DMPMNBz) CI3 is a mixture of olefins, mostly alpha-olefins, which have a number of carbons, preferably olefins of about 4 to 12 carbon atoms. The characteristics of the oligomers thus obtained in the reactions are shown in Table 1.

EXAMPLE 11:

Oliaomerization reaction with chrome catalysts

The oligomerization reaction system was saturated with the catalytic precursor Cr (DMPMNBu) CI3 obtained as described in Example 3 with an ethylene solution and the oligomerization reaction was initiated by addition to the precursor 30 μιτιοΙ reaction system catalytic Cr (DMPMNBu) CI3 diluted in toluene.

The oligomerization reaction was analogous to that described in Example 9 except for the catalytic precursor type.

The product of oligomerization reactions with the precursor Cr (DMPMNBu) CI3 is a mixture of olefins, mostly alpha-olefins, which have a number of carbons, preferably olefins of 4 to 12 carbon atoms.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 1.

EXAMPLE 12:

Oligomerization reaction with chrome catalysts

The oligomerization reaction system was saturated with the catalytic precursor Cr (DMPMS) CI3 obtained as described in Example 4 with an ethylene solution and the oligomerization reaction was initiated by the addition of the 30 μmol reaction system of the precursor. catalytic Cr (DMPMS) CI3 diluted in toluene.

The oligomerization reaction was analogous to that described in Example 9 except for the catalytic precursor type.

The product of the oligomerization reactions with the precursor Cr (DMPMS) CI3 is a mixture of olefins, mostly alpha olefins, which have a number of carbons, preferably olefins of 4 to 12 carbon atoms. The characteristics of the oligomers thus obtained in the reactions are shown in Table 1.

EXAMPLE 13:

Oligomerization reaction with chrome catalysts

The oligomerization reaction was analogous to that described in Example 12 except for the amount of catalytic precursor, which was 10 pmol.

The product of the oligomerization reactions with the precursor Cr (DMPMS) CI3 is a mixture of olefins, mostly alpha olefins, which have a number of carbons, preferably olefins of 4 to 12 carbon atoms.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 1.

EXAMPLE 14:

Oligomerization reaction with nickel catalysts

Alpha olefins were produced in a sterile humid environment by autoclaving at a temperature in the range 30 ° C to 60 ° C, atmospheric pressure of 20 atm and using a process comprising the following: phases:

1) 40 ml of a solution is injected into the reactor under argon atmosphere (in the present embodiment, the solution introduced into the reactor comprises a first solution, a toluene solution and a second solution which serves as a cocatalyst, for example a solution of methylaluminoxane, ΜΑΟ, with an Al / Cr molar ratio of 250 mol / mol);

2) the ethylene oligomerization reaction system is saturated;

3) the oligomerization reaction is initiated by the addition of 10 μιηοΙ to the reaction system of the diluted toluene catalytic precursor Ni (DMPMNBz) CI2;

4) The oligomerization reaction is interrupted by depressurizing and cooling the system. Initially, the ethylene solution is injected into the reaction system continuously so that the ethylene pressure remains constant. After approximately 20 min of development of the oligomerization reaction the reaction is stopped by depressurization and cooling of the system to -20 ° C. Thereafter an amount of cyclohexane is added to said system. Said cyclohexane solution serves as an internal standard for the reaction and the amount added must respect the proportions of the mixture. After addition of the cyclohexane solution, the oligomerization reaction product is analyzed by gas chromatography technique.

The product of the oligomerization reactions with the precursor Ni (DMPMNBz) CI2 obtained as described in Example 5 is a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 15:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 14 except that the temperature was 60 ° C.

The product of oligomerization reactions with the precursor Ni (DMPMNBz) CI2 is characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 16:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 14 except for the type of catalytic precursor. The product of the oligomerization reactions with the precursor Ni (DMPMNBu) CI2 obtained as described in Example 6 is characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 17:

Oligomerization reaction with nickel catalysts

The oligomerization reaction system was saturated with the catalytic precursor Ni (DMPMS) CI2 obtained as described in Example 7 with an ethylene solution and the oligomerization reaction was initiated by addition to the precursor 10 μιτιοΙ reaction system. Ni (DMPMS) CI2 diluted in toluene.

The oligomerization reaction was analogous to that described in Example 14 except for the type of catalytic precursor.

The product of oligomerization reactions with the precursor Ni (DMPMS) CI2 is characterized by a mixture of butenes, mostly composed of butene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 18:

Oligomerization reaction with nickel catalysts

The oligomerization reaction system was saturated with the catalytic precursor Ni (DFPMS) CI2 obtained as described in Example 8 with an ethylene solution and the oligomerization reaction was initiated by addition to the precursor 10 pmol reaction system Ni (DFPMS) CI2 diluted in toluene.

The oligomerization reaction was analogous to that described in Example 14 except for the type of catalytic precursor.

The product of oligomerization reactions with the precursor Ni (DFPMS) CI2 is characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 19:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 14 except for the type of cocatalyst. Diethylaluminum chloride (DEAC) (Al / Ni = 250) was used instead of MAO.

The product of oligomerization reactions with the precursor Ni (DMPMNBz) CI2 is characterized by a mixture of butenes, mostly composed of butene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 20:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 16 except for the type of cocatalyst. Diethylaluminum chloride (DEAC) (Al / Ni = 250) was used.

The product of oligomerization reactions with the precursor Ni (DMPMNBu) CI2 is characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 21:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 17 except for the type of cocatalyst. Diethylaluminum chloride (DEAC) (Al / Ni = 250) was used.

The product of oligomerization reactions with the precursor Ni (DMPMS) CI2 is characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 22:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 21 except for the molar ratio (Al / Ni = 50).

The product of oligomerization reactions with the precursor Ni (DMPMS) CI2 is characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reactions are shown in Table 2.

EXAMPLE 23:

Oligomerization reaction with nickel catalysts

The oligomerization reaction was analogous to that described in Example 18 except for the type of cocatalyst. Diethylaluminum chloride (DEAC) (Al / Ni = 250) was used.

The products of oligomerization reactions with the precursor Ni (DFPMS) CI2 are characterized by a mixture of butenes, mostly composed of butene-1, and a small fraction characterized as hexene-1.

The characteristics of the oligomers thus obtained in the reaction are shown in Table 2.

The invention described herein should be considered as one of the possible embodiments as well as the aspects discussed. Of course, the invention is not limited to such embodiments and those skilled in the art will appreciate that any particular feature introduced therein should be understood as merely to facilitate understanding and cannot be realized without departing from the inventive concept described.

The result of the oligomerization reaction employing the Cr (III) catalyst containing the bis [(3,5-dimethyl-1-pyrazolyl) methyl)] benzylamine (DMPMNBz) ligand (Example 9) shows that this catalytic system has high selectivity in production of hexene-1 (α-C6 = 39.34%) and octene-1 (α-C8 = 23.54%).

The selectivity of this system remains high even when performing the reaction at a higher temperature (Example 10, 100 ° C), where production of hexene-1 (a - C6 = 29.59%) and octene-1 (a - C8 = 19.98%).

Substitution of the benzyl group (Bz) by the n-butyl group (Bu) (Example 11) shows that the Cr (III) catalyst continues to exhibit high selectivity in hexene-1 production (a - C6 = 24.54%) and octeno-1 (α-C8 = 14.69%). These results indicate that the formation of cyclo-five systems leads to the formation of more selective catalysts for hexene-1 and octeno-1.

The oligomerization reaction using Cr (DMPMS) CI3 (Example 12) shows that this catalyst has a high rotational frequency in the order of 26,326 h "1, with high selectivity for alpha olefins (> 91.0%).

Studies related to the influence of catalyst concentration in the reactor showed that decreasing catalyst concentration from 30 μmol to 10 μmol (Example 13) provided an increase in "FR" from 26,326 h ~ 1 to 45,741 h ~ 1, suggesting that the use of A lower amount of catalyst determines the formation of a larger amount of catalytically active species.

Ni (II) catalysts, under activation with ΜΑΟ, are active in ethylene dimerization. Moderate rotation frequencies (RFs) were obtained between 3,900 and 18,900 h ~ 1 (Examples 14, 16 and 18).

The catalytic system containing a sulfur bridge ligand and methyl with substituents at positions 3 and 5 of the pyrazole rings had a high "RF" of 104,500 h "1 (Example 17).

The catalytic performance for ethylene dimerization is substantially influenced by the type of binder. Thus, the N-benzyl containing catalyst (Example 14) as a substituent is 3 times more active than the N-butyl containing catalyst (Example 16). However, in the latter case, the selectivity for butene-1 was better, reaching 93.7% with minimal butene-2 and hexene production.

Also, the presence of larger groups such as phenyl (compared to methyl groups) linked to pyrazolyl groups determines a large decrease in catalytic activity for (NSN) Ni (II) systems (compare Examples 17 and 18).

In addition, catalyst systems containing sulfur bridged bis (pyrazolyl) linkers (Example 17, FR = 104,500 h "1), such as NiCl 2 (bis [2 - ((3,5-dimethyl-1-pyrazolyl) methyl) linker] ] sulfide} that showed activity nearly 2 times higher than NiCI2 {bis [2 - ((3,5-dimethyl-1-pyrazolyl) ethyl)] sulfide} activity (FR = 57,200 h_1, Ajellal, N Kuhn, MCA; Boff, ADG; Hoerner, M.; Thomas, CM; Carpentier, J.-F.; Casagrande Jr., OL; Organometallics, 2006, 25, 1213), show that the formation of a cyclic system -a-five gives the catalyst greater stability and no significant impact on butene-1 selectivity, which remained around 70% - 73%.

For all ΜΑΟ-activated nickel complexes, selectivity for butenes is high, especially for butene-1, reaching 81.1% - 93.7% of the total olefins formed in oligomerization reactions under these conditions.

Larger amounts of butene-2 (about 26%) are produced with the sulfur bridge-containing Ni (II) catalyst (Example 17). In all cases, minimal amounts of hexenes were produced and no polymer was detected.

TABLE 1 Result of gas chromatography analysis: product distribution of oligomerization reactions with Cr (III) catalysts

<table> table see original document page 26 </column> </row> <table>

Reaction conditions: 80 ° C, 20 bar, 50 mL of toluene, 30 μΐηοΙ Cr, Al / Cr = 300 (ΜΑΟ).

(a) 100C, 20 bar, 50 mL toluene, 30 μmol Cr, Al / Cr = 300 (().

(b) 80 ° C, 20 bar, 50 mL toluene, 10 μmol Cr 1 Al / Cr = 300 (ΜΑΟ).

(c) mol of ethylene converted (mol of Cr) "1 h" 1, as determined by quantitative CGL, Cn, amount of olefin with carbon atoms in the oligomers; α - Cn, amount of terminal alkenes in fraction Cn; determined by quantitative CGL. TABLE 2 Gas chromatography analysis results: total C4 and isomer distribution of oligomerization reactions with Ni (II) catalysts

<table> table see original document page 27 </column> </row> <table>

Reaction conditions: 30 ° C, 20 bar, 40 mL toluene, 10 μίτιοΙ Cr, Al / Ni = 250.

(a) 60 ° C, 20 bar, 40 mL toluene, 10 μπιοΙ Cr, Al / Ni = 250 (ΜΑΟ).

(b) 30 ° C, 20 bar, 40 mL of toluene, 10 μπιοΙ Cr, Al / Ni = 50 (ΜΑΟ).

(c) Molecule of ethylene converted (mol of Ni) "1 h ~ 1, determined by quantitative CGL, Cn, amount of olefin with carbon atoms in the oligomers; a-Cn, amount of terminal alkenes in the Cn fraction; determined by CGL quantitative.

Claims (20)

1. CHROME AND NICKEL CATALYZERS FOR OLIGOMERIZATION REACTIONS, comprising transition metal-based catalytic precursors of groups 6 and 10 of the Periodic Table of chemical elements and obtained from polyidentated nitrogen ligands, characterized by said precursors being composed coordinates and have the general formula LMXni where "M" represents a metal, "X" represents an anion, "n" represents the number of "X" anions present in each molecule, which ranges from 1 to 3, and " L "is a polyidentated Nitrogen Ligand represented by the formula E [(CH2) (Pz)] 2R4, where Έ" represents a heterocyclic pyridine ring, an imidazole ring or an element selected from oxygen, nitrogen and sulfur, " Pz "represents a group which comprises a pyrazolyl ring with a nitrogen atom as heteroatom, radicals R1, R2 and R3, located respectively at positions 3, 4 and 5 of the pyrazolyl ring, which are they teach between hydrogen atoms and hydrocarbon radicals having a number of carbon atoms of 1 or more, and finally R4 represents a hydrogen atom or a radical selected from the C4-C2O aliphatic hydrocarbyl, a C1-C20 aliphatic hydrocarbyl substituted with the at least one C6-C14 aromatic radical, an unsubstituted C6-C20 aromatic hydrocarbon and a C6-C20 aromatic hydrocarbon substituted with at least one C1-C10 alkyl radical. Chromium and nickel catalysts for oligomerization reactions according to claim 1, characterized in that said two groups "Pz" in the formula E [(CH2) (Pz)] 2R4 are the same or different from each other, at least one being of positions 3, 4 and 5 of the pyrazolyl ring filled with a hydrocarbyl radical. Chromium and nickel catalysts for oligomerization reactions according to claim 1, characterized in that said radical R1 located at position 3 of the pyrazolyl ring is selected from n-butyl, iso-butyl, tert-butyl, iso-pentyl, neo-pentyl, phenyl, benzyl, cumenyl and mesityl. Chromium and nickel catalysts for oligomerization reactions according to claim 1, characterized in that said "X" anions are selected from chloride, bromide, fluoride and alkyl. Chromium and nickel catalysts for oligomerization reactions according to claim 1, characterized in that said transition metal "M" is selected from the elements of groups 6 and 10 of the Periodic Table, from chromium, molybdenum, tungsten metals. and palladium and have oxidation state between +2 and +6. Chromium catalysts for oligomerization reactions according to claim 1, characterized in that said catalysts of general formula LMX3 are obtained by reaction between tridentate nitrogenous binders and Cr (THF) 3CI3 adduct or equivalent compound, in the presence of of a solvent. Nickel catalysts for oligomerization reactions according to claim 1, characterized in that said catalysts of general formula LMX2 are obtained by reaction between tridentate nitrogenous binders and the Ni (dimethoxyethane) adduct or equivalent compound or a Nickel salt of formula NiX2 in the presence of a solvent where "X" is selected from halide, acetate, acetylketonate and nitrate. Chromium catalysts for oligomerization reactions according to claim 1, characterized in that said catalysts are obtained from precursors Cr (DMPMNBu) CI3 (Formula 3), Cr (DMPMNBu) CI3 (Formula 4) and Cr (DMPMS). ) CI3 (Formula 5) having the following structural formulas: <formula> formula see original document page 30 </formula> FORMULA 3 <formula> formula see original document page 30 </formula> FORMULA 4 <formula> formula see original document page 30 </formula> FORMULA 5 Nickel catalysts for oligomerization reactions according to claim 1, characterized in that said catalysts are obtained from precursors Ni (DMPMNBz) CI2 (Formula 6), Ni (DMPMNBu) CI2 (Formula 7), Ni (DMPMS) ) CI2 (Formula 8) and Ni (DFPMS) CI2 (Formula 9) having the following structural formulas: <formula> formula see original document page 30 </formula> formula 6 <formula> formula see original document page 30 </formula> FORMULA 7 <formula> formula see original document page 30 </formula> FORMULA 8 <formula> formula see original document page 30 </formula> FORMULA 9 ALPHA-OLEFIN OBTAINING PROCESS, from oligomerization reactions of one or more olefins, particularly from ethylene, catalyzed by polyidentated coordinating compounds which comprise group 6 transition metal-based compounds of Table Periodic, particularly chromium (III) metal, and group 10 transition metal-based compounds, particularly nickel (II) metal, at temperatures ranging from 70 ° C to 90 ° C for group transition metals 6 and preferably between 20 ° C and 60 ° C for group -10 transition metals, absolute pressure ranging from 1 bar to 140 bar and residence time ranging from 1 to 240 minutes, characterized by the use of a catalytic system comprising: (a) a catalyst obtained by reacting between a precursor containing a tridentate ligand group and a transition metal salt selected from groups 6 and 10 of the Periodic Table; (b) a B (C6F5) 3-derived alkylaluminum, hydrocarbylaluminoxane or borane cocatalyst, pure or combined, and comprising the following steps: 1) preparing a catalyst of formula LMXn, wherein: "M" represents a transition metal selected from groups 6 and 10 of the Periodic Table; "X" represents an anion; "n" represents the number of "X" anions present in each molecule, ranging from 1 to 3; "L" is a binder represented by the formula E [(CH2) (Pz)] 2 R4 and the structure: <formula> formula see original document page 31 </formula> where "E" represents an oxygen, nitrogen, sulfur or a heterocyclic ring (pyridine, imidazole), R4 represents a hydrogen atom or a radical selected from the C4-C2O aliphatic hydrocarbyl radicals, C1-C20 aliphatic hydrocarbyl substituted with at least one C6-C14 aromatic hydrocarbyl radical, Unsubstituted -C20 or C6 -C20 aromatic hydrocarbyl substituted with at least one C1-C10 alkyl radical, and "Pz" represents a group which comprises a pyrazolyl ring with a nitrogen atom as heteroatom and R11 R2 and R3 radicals located respectively at positions 3, 4 and 5 of the pyrazolyl ring selected from hydrogen atoms and hydrocarbyl radicals having 1 or more carbon atoms; -2) preparing a reaction mixture containing said catalyst, a solvent and an olefin; -3) provide conditions for this reaction mixture to react in solution to obtain a series of alpha olefins; -4) separating the alpha olefins obtained as the final product, consisting of a mixture of carbon chain olefins in the range of 4 to 12 carbon atoms. ALPHA-OLEPHINE PROCESSING according to Claim 10, characterized in that the molar ratio between boron-type co-catalyst boron and catalyst group "M" metals is equal to 1: 1. ALPHA-OLEPHINE PROCESSING according to Claim 10, characterized in that the molar ratio between the aluminum of the organoaluminum-type co-catalyst and the "M" metal of the catalyst groups 6 and 10 is be between 1: 1 and 1: 10,000, preferably between -1: 50 and 1: 5,000 and more preferably between 1: 200 and 1: 2,000. ALPHA-OLEPHINE PROCESSING according to claim 10, characterized in that said organoaluminium-type cocatalyst is a hydrocarbylaluminoxanes selected from alkylaluminoxanes, arylaluminoxanes and alkylaryluminoxanes, with C1-C4 alkyl groups. ALPHA-OLEPHINE PROCESSING according to claims 10 and 13, characterized in that said organoaluminium-type cocatalyst is a mixture containing at least two alkylaluminum or hydrocarbylaluminoxane-type compounds. ALPHA-OLEFIN OBTAINING PROCESS according to Claim 10, characterized in that the catalytic precursors, including Cr (DMPMNBz) CI3 (Formula 3), Cr (DMPMNBu) CI3 (Formula 4), Cr (DMPMS), are used. ) CI3 (Formula 5), Ni (DMPMNBz) CI2 (Formula 6), Ni (DMPMNBu) CI2 (Formula 7), Ni (DMPMS) CI2 (Formula 8) and Ni (DFPMS) CI2 (Formula 9) both in liquid phase as in gas phase. ALPHA-OLEPHIN OBTAINING PROCESS according to claims 10 and 15, characterized in that said catalysts participate in the reactions, either solubilized in the reaction medium or dispersed in an organoaluminate ionic liquid or in suspension, supported on a silica support; of magnesium chloride or alumina. ALPHA-OLEPHINE PROCESSING according to claims 10 and 15, characterized in that the monomers used in the reaction comprise one or more olefins of 2 to 12 carbon atoms. ALPHA-OLEFIN OBTAINING PROCESS according to claim 17, characterized in that the olefin fraction present in the largest quantity in the reaction contains ethylene or propene. ALPHA-OLEPHINE PROCESSING according to Claim 16, characterized in that the reaction carried out in a single-phase system uses as a solvent a supporting or polar compound, liquid or gaseous. ALPHA-OLEPHINE PROCESSING according to Claim 19, characterized in that the supporting solvent is selected from hexane, heptane or cyclohexane, and the polar solvent is selected from toluene, chlorobenzene or dichloromethane.