Alpha-diimine nickel metal organic compound and preparation method thereof

Abstract

The invention relates to an alpha-diimine nickel metal organic compound and a preparation method thereof. The preparation method comprises the following steps: adding NiBr2 (DME) and alpha-diimine into a dichloromethane solution for reaction under the protection of an inert atmosphere, reducing an obtained product in a diethyl ether or n-hexane solution by using metallic sodium, and then reacting with 1,5-cyclooctadiene to obtain a mononuclear nickel metal organic compound of alpha-diimine. The preparation method provided by the invention is simple, is high in product yield and good in purity and can be used as an olefin polymerization catalyst.

Description

technical field

[0001] The invention relates to an α-diimine nickel metal organic compound and a synthesis method thereof. Background technique

[0002] The application of transition metal complexes in the catalytic polymerization of olefins is an important research field. The selection of the steric hindrance of the ligands of such complexes is crucial to the metal-small molecule combination and subsequent reactions in the reaction. α -Diimine, as a nitrogen-containing ligand, can flexibly design substituents on the nitrogen atom to adjust its steric hindrance for the synthesis of new transition metal catalysts. Generally speaking, only non-classical metal centers with low coordination number and low valence can stabilize small molecules containing unsaturated bonds, so α - Diimine is very suitable as a ligand for stabilizing low-valence metals, and helps the formation of subsequent reactions and the stability of products. Nickel is an important element in nature. It play...

Examples

Embodiment 1

[0024] 1. Preparation of α-diimine nickel bromide complex

[0025] Under inert gas conditions, add NiBr 2 (DME) (1.543g, 5.0mmol) and ɑ-diimine ligand (2.100g, 5.2mmol), then add 30 mL of dichloromethane solution after dehydration, stir at room temperature for 12 hours, spin evaporate Part of the dichloromethane solution was washed with 20 mL of n-hexane and dried to obtain ɑ-diimine nickel bromide complex.

[0026] 2. Preparation of α-diimine mononuclear nickel metal organic compounds

[0027] Under anhydrous and oxygen-free conditions, 0.046 g (2.0 mmol) of metal Na was added to the diethyl ether (30 mL) turbid solution containing 0.622 g (1.0 mmol) of the α-diimine nickel bromide complex synthesized above, and stirred The solution turned green in 24 hours, and then 125 μL of 1,5-cyclooctadiene (1.0 mmol) was added to the solution, stirred at room temperature for 24 hours, the solution turned dark green, concentrated to about 6 mL, and crystallized at room temperature to o...

Embodiment 2

[0031] In step 2 of the preparation of ɑ-diimine mononuclear nickel metal organic compound in Example 1, under anhydrous and oxygen-free conditions, 0.046 g (2.0 mmol) of metal Na was added to the 0.622 g (1.0 mmol) In the diethyl ether (30 mL) turbid solution of ɑ-diimine nickel bromide complex, stir for 24 hours and the solution turns green, then add 125 μL 1,5-cyclooctadiene (1.0 mmol) to the solution, stir at room temperature After 36 hours, the solution turned dark green, concentrated to about 6mL, and stood to crystallize at -20°C to obtain dark green crystals, which were ɑ-diimine mononuclear nickel metal organic compounds. The yield was 0.435 g, and the yield was 76.2%, belonging to the monoclinic system, and its crystal structure and unit cell parameters are the same as in Example 1.

Embodiment 3

[0033] In step 2 of the preparation of ɑ-diimine mononuclear nickel metal organic compound in Example 1, under anhydrous and oxygen-free conditions, 0.046 g (2.0 mmol) of metal Na was added to the 0.622 g (1.0 mmol) ɑ-Diimine nickel bromide complex in n-hexane (30 mL) turbid solution, stirred for 24 hours, the solution turned green, then added 125 μL 1,5-cyclooctadiene (1.0mmol) to the solution, room temperature Stirred for 36 hours, the solution turned dark green, concentrated to about 6mL, and stood to crystallize at room temperature to obtain dark green crystals, which were ɑ-diimine mononuclear nickel organometallic compounds, with a yield of 0.459 g and a yield of 80.3 %, belongs to the monoclinic system, and its crystal structure and unit cell parameters are the same as in Example 1.

technical field

[0001] The invention relates to an α-diimine nickel metal organic compound and a synthesis method thereof. Background technique

[0002] The application of transition metal complexes in the catalytic polymerization of olefins is an important research field. The selection of the steric hindrance of the ligands of such complexes is crucial to the metal-small molecule combination and subsequent reactions in the reaction. α -Diimine, as a nitrogen-containing ligand, can flexibly design substituents on the nitrogen atom to adjust its steric hindrance for the synthesis of new transition metal catalysts. Generally speaking, only non-classical metal centers with low coordination number and low valence can stabilize small molecules containing unsaturated bonds, so α - Diimine is very suitable as a ligand for stabilizing low-valence metals, and helps the formation of subsequent reactions and the stability of products. Nickel is an important element in nature. It play...

Examples

Embodiment 1

[0024] 1. Preparation of α-diimine nickel bromide complex

[0025] Under inert gas conditions, add NiBr 2 (DME) (1.543g, 5.0mmol) and ɑ-diimine ligand (2.100g, 5.2mmol), then add 30 mL of dichloromethane solution after dehydration, stir at room temperature for 12 hours, spin evaporate Part of the dichloromethane solution was washed with 20 mL of n-hexane and dried to obtain ɑ-diimine nickel bromide complex.

[0026] 2. Preparation of α-diimine mononuclear nickel metal organic compounds

[0027] Under anhydrous and oxygen-free conditions, 0.046 g (2.0 mmol) of metal Na was added to the diethyl ether (30 mL) turbid solution containing 0.622 g (1.0 mmol) of the α-diimine nickel bromide complex synthesized above, and stirred The solution turned green in 24 hours, and then 125 μL of 1,5-cyclooctadiene (1.0 mmol) was added to the solution, stirred at room temperature for 24 hours, the solution turned dark green, concentrated to about 6 mL, and crystallized at room temperature to o...

Embodiment 2

[0031] In step 2 of the preparation of ɑ-diimine mononuclear nickel metal organic compound in Example 1, under anhydrous and oxygen-free conditions, 0.046 g (2.0 mmol) of metal Na was added to the 0.622 g (1.0 mmol) In the diethyl ether (30 mL) turbid solution of ɑ-diimine nickel bromide complex, stir for 24 hours and the solution turns green, then add 125 μL 1,5-cyclooctadiene (1.0 mmol) to the solution, stir at room temperature After 36 hours, the solution turned dark green, concentrated to about 6mL, and stood to crystallize at -20°C to obtain dark green crystals, which were ɑ-diimine mononuclear nickel metal organic compounds. The yield was 0.435 g, and the yield was 76.2%, belonging to the monoclinic system, and its crystal structure and unit cell parameters are the same as in Example 1.

Embodiment 3

[0033] In step 2 of the preparation of ɑ-diimine mononuclear nickel metal organic compound in Example 1, under anhydrous and oxygen-free conditions, 0.046 g (2.0 mmol) of metal Na was added to the 0.622 g (1.0 mmol) ɑ-Diimine nickel bromide complex in n-hexane (30 mL) turbid solution, stirred for 24 hours, the solution turned green, then added 125 μL 1,5-cyclooctadiene (1.0mmol) to the solution, room temperature Stirred for 36 hours, the solution turned dark green, concentrated to about 6mL, and stood to crystallize at room temperature to obtain dark green crystals, which were ɑ-diimine mononuclear nickel organometallic compounds, with a yield of 0.459 g and a yield of 80.3 %, belongs to the monoclinic system, and its crystal structure and unit cell parameters are the same as in Example 1.

Images