CN1197882C - Bivalent rare earth coordination compound containing electron-donating group organic ligand, its synthesis method and application - Google Patents

Abstract

The invention relates to a class of divalent rare earth complexes containing electron-donating group organic ligands, a synthesis method and uses. The complex is a kind of indenyl divalent rare earth complex with electron-donating groups containing oxygen or sulfur, which is obtained by reacting the corresponding organic ligand potassium salt with Ln(II)I ₂ ·nTHF, where Ln is Sm(II) Or Yb(II), n=0-4, or obtained by reducing the corresponding trivalent rare earth chloride with metal sodium. Such complexes can be used to catalyze the polymerization of methyl methacrylate, caprolactone and valerolactone. The structural formula of the complex is as follows: In the above structural formula, Ln is Sm(II), Eu(II) or Yb(II), X is oxygen or sulfur, R, R ¹ or R ² are -H, -C _1-4 Hydrocarbyl, aryl, benzyl or trimethylsilyl, Q is -C _1-4 hydrocarbyl, aryl, benzyl or does not exist, --- or ... is single bond or no bond, → is coordination Healthy, Z or Y=-CH ₂ CH ₂ -or does not exist, U=L or-XQ; Wherein, when Z= does not exist, Q is the hydrocarbon group of-C _1-4 , aryl or benzyl, U is -XQ, --- is no bond, ... is a single bond, Y=-CH ₂ CH ₂ -. When Q= does not exist, Z=-CH ₂ CH ₂ -, U is L, L=tetrahydrofuran, ethylene glycol dimethyl ether or ether, ... means no bond, ——— means single bond, Y= does not exist .

Description

Divalent rare earth complex containing electron-donating group organic ligand, synthesis method and application

technical field

The invention relates to a divalent rare earth complex containing an electron-donating group organic ligand, a synthesis method and an application. The ligand is obtained by reacting the corresponding organic ligand metal salt with Ln(II)I ₂ ·nTHF, or reducing the corresponding trivalent rare earth chloride by metal sodium, and can catalyze the polymerization of methyl methacrylate with high activity.

technical background

In the last ten years, rare earth metallocene complexes have become one of the research hotspots. The hydrides and alkyl compounds of the rare earth metallocenes have the same electronic structure as the active species of the IVB metallocenes, ie Kaminsky catalysts, and they can catalyze olefin polymerization with a single component without using a co-catalyst. In addition to catalyzing the polymerization of olefins, another feature of rare earth metallocene compounds is that they can catalyze the polymerization of polar monomers (such as methyl methacrylate, caprolactone, acrylonitrile, etc.) to obtain high molecular weight, narrow molecular weight distribution and high stereoregularity. Polar polymers, and catalyzed copolymerization of polar monomers and olefins to obtain copolymers with superior properties. In addition, rare earth metallocenes also play an important role in catalyzing some organic reactions.

Polymethyl methacrylate is an organic polymer material with a wide range of uses. Free radical polymerization and anionic polymerization are two main methods for preparing polymethyl methacrylate. Free radical polymerization is usually achieved by initiators, light, radiation, heat, and the like. Anionic polymerization uses metal organic compounds as initiators, such as n-butyllithium, alkyllithium, lithium aluminum tetrahydride and sodium biphenyl, etc. In recent years, Yasuda et al. have found that trivalent rare earth hydrides and methyl compounds and divalent rare earth complexes can catalyze the polymerization of methyl methacrylate to obtain syndiotactic polymethyl methacrylate (H.Yasuda, H.Yamamoto, K. Yokota, S. Miyake, A. Nakamura. J. Am. Chem. Soc., 1992, 114, 4908; H. Yasuda, H. Yamamoto, M. Yamashita, K. Yokota, A. Nakamura, S. Miyake, Y Kai, N. Kanehisa. Macromolecules., 1993, 26, 7134). The structural formula of the complex is as follows:

T.J.Marks et al. also reported that bridged achiral and bridged chiral rare earth metal organic complexes can stereoselectively control the polymerization of methyl methacrylate. The experimental results show that the chiral catalyst containing (+)-neomenthyl (neomenthyl) can obtain isotactic polymethyl methacrylate, however, the chiral catalyst containing (-)-menthyl (menthyl) can obtain between Syndiotactic polymer, syndiotactic content and achiral bridging rare earth catalyst polymerization results of methyl methacrylate (M.A.Giardello, Y.Yamamoto, L.Brard, T.J.Marks.J.Am.Chem.Soc., 1995 , 117, 3276). The structural formula of the complex is as follows:

Qian Changtao and others synthesized some single-atom bridged fluorenyl cyclopentadienyl rare earth amine compounds and alkyl compounds. These rare earth compounds can single-component catalyze the polymerization of methyl methacrylate to obtain syndiotactic polymethyl methacrylate (C. Qian, W. Nie, J. Sun. Organometallics., 2000, 19, 4134). The structural formula of the complex is as follows:

E=CH,N.

Qian Changtao and others also synthesized other racemic oxygen-bridged bis-indenyl rare earth alkyl compounds and amino compounds. These compounds catalyze the polymerization of methyl methacrylate at low temperature and then obtain a very high polymer (C.Qian, G.Zou, Y.Chen, J.Sun.Organometallics., 2001, 20 , 3106). The structural formula of the complex is as follows:

Qian Changtao and others have reported the synthesis and structure of bis-1-(2-dimethylaminoethyl)indenyl Sm(II) and Yb(II) complexes (C.Qian, H.Li, W.Nie, J. Sun. J. organomet. Chem., 1999, 589, 59):

Ln=Sm, Yb.

Contents of the invention

The object of the present invention is to provide a kind of divalent rare earth complexes containing electron-donating group organic ligands.

Another object of the present invention is to provide a synthetic method for synthesizing the above complex.

The present invention also provides a use of the above-mentioned complex.

The structural formula of a class of divalent rare earth complexes containing electron-donating group organic ligands provided by the present invention is as follows:

为无键，---为单键，Y＝不存在。Wherein, Ln is Sm(II), Eu(II) or Yb(II), X is oxygen or sulfur, R, R ¹ or R ² are -H, -C _1-4 hydrocarbyl, aryl, benzyl or Trimethylsilyl, Q is -C _1-4 hydrocarbyl, aryl, benzyl or absent, --- or It is a single bond or no bond, → is a coordination key, Z or Y=-CH ₂ CH ₂ -or does not exist, U=L or -XQ; wherein, when Z=does not exist, Q is-C _1-4 Hydrocarbyl, aryl or benzyl, U is -XQ, --- is no bond, It is a single bond, Y=-CH ₂ CH ₂ -. When Q = does not exist, Z = -CH ₂ CH ₂ -, U is L, L = tetrahydrofuran, ethylene glycol dimethyl ether or diethyl ether,

For no bond, --- for a single bond, Y = does not exist.

The structural formula of a class of divalent rare earth complexes containing electron-donating group organic ligands of the present invention can also be as an example:

Wherein X, Q, L, Ln, R, R ¹ and R ² are as previously described.

The above-mentioned divalent rare earth complex of the present invention is obtained by reacting the corresponding organic ligand potassium salt with Ln(II)I ₂ ·nTHF, wherein n=0-4. Or it can be obtained by reducing the corresponding trivalent rare earth chloride with sodium metal. The yield is 20-80%. Specifically, it is accomplished by the following reaction:

(1) by the structural formula as The corresponding organic ligands are reacted in an organic solvent for 0.5-24 hours with butyllithium, metal sodium or metal potassium at a molar ratio of 1:1-5, and the reaction temperature is -78°C to 40°C. Metal salts of corresponding organic ligands;

(2) Then in an organic solvent and at -78°C to 40°C, when the molar ratio of the metal salt of the organic ligand of the reaction product of the above (1) to Ln(II)I ₂ ·nTHF is 1:0.5-5, the reaction Obtain divalent _rare earth complex in 0.5-48 hours; Or by the reaction product of (1) and Ln (III) Cl When molar ratio is 1: 0.5-4, react 0.5-48 hours in organic solvent, reaction temperature is -78°C to 40°C, then react in an organic solvent at -30-40°C for 2-48 hours when the molar ratio of the obtained trivalent rare earth substituted indenyl chloride to metal sodium is 1:0.5-5, and then reduce Corresponding trivalent rare earths replace indenyl chlorides to obtain divalent rare earth organic complexes;

Wherein X, Ln and R are as above, n=0～4, A is the hydrocarbyl of-C _1-4 , aryl, benzyl or the substituted indenyl of following structural formula:

Z、R¹或R²如上所述。

Z, R ¹ or R ² are as described above.

The organic solvent is tetrahydrofuran, ethylene glycol dimethyl ether, petroleum ether, diethyl ether or toluene.

The above-mentioned divalent rare earth complexes containing electron-donating group organic ligands of the present invention are not only easy to synthesize, but also can catalyze methyl methacrylate, caprolactone, etc. and valerolactone polymerization.

Detailed ways

The following examples will help to further understand the present invention, but can not limit the content of the present invention.

Example 1

Suspend 1.2g of potassium metal in 20mL of tetrahydrofuran, add dropwise a solution of 1.6g of 1.1'-3-oxopentamethylene bridged bisindene ligand in 20mL of tetrahydrofuran under cooling with ice water. After reacting for 5 hours, the solid was removed by centrifugation to obtain a potassium salt solution of the organic ligand. 1.32g Sm(III) _Cl3 was placed in 20 THF, cooled to room temperature, and then the potassium salt solution of the above organic ligand was added. After reacting for 48 hours, the precipitate was separated by centrifugation, and the precipitate was extracted with 80 mL of tetrahydrofuran, and the supernatants were combined. The solvent was distilled off in vacuo until a solid precipitated, and crystallized at -30°C to obtain 1.20 g of 1.1'-3-oxopentamethylene bridged bisindenyl samarium chloride with a yield of 42%.

At room temperature, 1.10 g of 1.1'-3-oxopentamethylene bridged bisindenyl samarium chloride was dissolved in 70 mL of tetrahydrofuran, and then 0.18 g of sodium sand was added. Under stirring, after reacting for three days, excess sodium sand and precipitates were removed by centrifugation, and the solvent was removed from the solution to obtain a black-red foamy solid. Extract the black-red foamy solid with 20mL tetrahydrofuran, and then add 40mL n-hexane to the solvent to obtain a black-red powdery solid. Recrystallize the obtained solid in ethylene glycol dimethyl ether (DME) to obtain a black-red block Crystal 1. 0.79 g of 1'-3-oxopentamethylene bridged bisindenyl samarium (II), yield 75%. Elemental analysis: O( _CH2CH2C9H6 ) _2Sm ( _DME ) _: calcd. C, 57.74; _H , 5.55. Found C, 56.92; H, 5.59.

Example 2

Suspend 1.2g of sodium metal in 20mL of tetrahydrofuran, add dropwise a solution of 1.68g of 1.1'-3-oxopentamethylene bridged bisindene ligand in 20mL of tetrahydrofuran under ice-water cooling. After 20 hours of reaction, the solid was removed by centrifugation to obtain a sodium salt solution of the organic ligand. 1.56g Yb(III)Cl3 was placed in 40 tetrahydrofuran, cooled to room temperature, and then the sodium salt solution of the above-mentioned organic ligand was added. After reacting for 36 hours, the precipitate was separated by centrifugation, and the precipitate was extracted with 100 mL of tetrahydrofuran, and the supernatants were combined. The solvent was distilled off in vacuo until a solid precipitated, and crystallized at -30°C to obtain 1.34 g of 1.1'-3-oxopentamethylene bridged bis-indenyl ytterbium chloride with a yield of 41%.

At room temperature, dissolve 0.96g of 1.1’-3-oxopentamethylene bridged bisindenyl ytterbium chloride in 70mL of tetrahydrofuran, and then add 0.15g of sodium sand. Under stirring, after reacting for three days, excess sodium sand and precipitates were removed by centrifugation, and the solution was desolvated to obtain a red foamy solid. Extract the black-red foamy solid with 20 mL of tetrahydrofuran, and then add 40 mL of n-hexane to the solvent to obtain a red powdery solid. Recrystallize the obtained solid in ethylene glycol dimethyl ether (DME) to obtain a red blocky crystal 1.1 0.74 g of '-3-oxopentamethylene bridged bis-indenyl ytterbium (II), yield 80%. Elemental Analysis: O(CH2CH2C9H6)2Yb(DME): Calcd. C, 55.42; H, 5.33. Found C, 54.51; H, 5.16.

Example 3

Dissolve 0.5g of 1.1'-3-oxopentamethylene bridged bisindene in 20mL of tetrahydrofuran or ether, and then add 0.6g of potassium sand. Under stirring, react until no bubbles are released. Centrifugation gave a light yellow-green solution. The light yellow-green solution was dropped into a tetrahydrofuran solution containing 1.223g SmI2 2THF. Under stirring, after two days of reaction. After centrifugation, the supernatant was concentrated to about 10 mL, and then 20 mL of n-hexane was added. After standing for a few days, a black solid precipitated out with a yield of 36%. Elemental Analysis: O(CH2CH2C9H6)2Sm(THF): Calcd. C, 59.76; H, 5.40. Found C, 58.51; H, 4.96.

Example 4

Dissolve 1.31g of 1-(2-methoxyethyl)indene in 20mL of tetrahydrofuran, and then add 0.29g of potassium sand. Under stirring, react until no bubbles are released. Centrifuge to obtain a light yellow-green solution. Drop the light yellow-green solution into a tetrahydrofuran solution of 1.59g SmI ₂ ·2THF. Under stirring, after two days of reaction. After centrifugation, the supernatant was concentrated to about 10 mL, and then 20 mL of n-hexane was added. After standing for several days, a black solid precipitated out with a yield of 36%. Elemental analysis: (CH ₃ OCH ₂ CH ₂ C ₉ H ₆ ) ₂ Sm: Calculated value C, 58.01; H, 5.27. Found C, 57.93; H, 4.97.

Example 5

Under a nitrogen atmosphere, put 36mg of 1.1'-3-oxopentamethylene bridged bisindenyl samarium(II)O(CH2CH2C9H6) ₂ Sm(THF) in a two-neck flask treated with oxygen and water removal , and then added 5.6 mL of tetrahydrofuran. Start stirring to dissolve 1.1'-3-oxopentamethylene bridged bisindenyl samarium(II)O(CH ₂ CH ₂ C ₉ H ₆ ) ₂ Sm(THF) in tetrahydrofuran, and cool the solution to -78°C . Further, under stirring, 1.3 g of methyl methacrylate was added. After 7 hours of polymerization, the polymerization was terminated with 6 mL of methanol solution containing 5% HCl. Add 20 mL of methanol to precipitate polymethylmethacrylate. The polymethylmethacrylate was collected by filtration, dissolved in chloroform, and precipitated with methanol. Filtration yielded a white polymer. It was dried under vacuum at 50° C. to a constant weight to obtain 1.06 g of polymethyl methacrylate. The conversion rate was 81%.

Example 6

Under a nitrogen atmosphere, place 21 mg of bis-1-(2-methoxyethyl)indenyl ytterbium (II) (CH ₃ OCH ₂ CH ₂ C ₉ H ₆ ) ₂ Yb in a double-necked bottle, and then added 3.4 mL of tetrahydrofuran. Stirring was started to dissolve bis-1-(2-methoxyethyl)indenyl ytterbium(II)(CH ₃ OCH ₂ CH ₂ C ₉ H ₆ ) ₂ Yb in THF, and the solution was cooled to -78°C. Further, under stirring, 0.84 g of methyl methacrylate was added. After 7 hours of polymerization, the polymerization was terminated with 6 mL of methanol solution containing 5% HCl. Add 20 mL of methanol to precipitate polymethylmethacrylate. The polymethylmethacrylate was collected by filtration, dissolved in chloroform, and precipitated with methanol. The white polymer was obtained by filtration, and dried under vacuum at 50° C. to a constant weight to obtain 0.73 g of polymethyl methacrylate. The conversion rate was 92%.

Example 7

Under a nitrogen atmosphere, 32 mg of bis-1-(2-methoxyethyl)indenyl samarium (II) (CH ₃ OCH ₂ CH ₂ C ₉ H ₆ ) ₂ Sm was placed in a double-necked bottle, and then add 11 mL of toluene. Stirring was started to dissolve bis-1-(2-methoxyethyl)indenyl samarium(II)(CH ₃ OCH ₂ CH ₂ C ₉ H ₆ ) ₂ Sm in toluene, and the solution was cooled to 0°C. Further, under stirring, 1.37 g of methyl methacrylate was added. After 7 hours of polymerization, the polymerization was terminated with 6 mL of methanol solution containing 5% HCl. Add 20 mL of methanol to precipitate polymethylmethacrylate. The polymethylmethacrylate was collected by filtration, dissolved in chloroform, and precipitated with methanol. After filtration, a white polymer was obtained, which was dried to a constant weight at 50° C. under vacuum to obtain 0.121 g of polymethyl methacrylate. The conversion rate was 94%.

Some aggregation results are shown in Table 1.

Table 1. Polymerization of methyl methacrylate catalyzed by divalent rare earth organic complexes

Catalyst Solvent T(℃) Conversion(%) Polymer Microstructure Mw Mn Mw/Mn

rr mr mm 10 ⁴ 10 ⁴

1 Toluene 0 94 29 46 25 8.81 3.07 2.87

THF 0 98 31 56 13 6.75 3.44 1.96

THF -78 75 65 30 5 16.9 7.22 2.34

2 Toluene 0 77 30 45 25

THF 0 64 39 48 13 5.93 2.55 2.32

THF -78 92 78 20 2

3 Toluene 0 54 44 28 28 6.24 13.4 2.29

THF 0 32 50 24 26 6.16 11.6 1.88

THF -78 81 47 24 29 5.11 10.7 2.10

4 THF 0 9

Conditions: catalyst/monomer = 1/200 (mol/mol). Tetrahydrofuran (THF)/monomer = 4/1 (V/V).

Toluene/monomer = 8/1 (V/V).

The structural formula of catalyst (1)-(4) is as follows:

Ln=Sm(1), Yb(2), Ln=Sm(3), Yb(4).

Claims (6)

1, a class contains the bivalent rare earth coordination of donor residues group organic ligand, it is characterized in that structural formula is as follows: In the said structure formula, Ln is Sm (II), Eu (II) or Yb (II), and X is oxygen or sulphur, R, R ¹Or R ²For-H ,-C _1-4Alkyl, aryl, benzyl or trimethyl silicon based, Q is-C _1-4Alkyl, aryl, benzyl or do not exist,---or

For singly-bound or there is not key, → for coordination strong, Z or Y=-CH ₂CH ₂-or do not exist, U=L or-XQ; Wherein, when Z=did not deposit, Q was-C _1-4Alkyl, aryl or benzyl, U is-XQ,---be no key, Be singly-bound, Y=-CH ₂CH ₂-; When Q=does not exist, Z=-CH ₂CH ₂-, U is L, L=tetrahydrofuran (THF), glycol dimethyl ether or ether,

Be no key,---be singly-bound, Y=does not exist.

2, a class as claimed in claim 1 contains the bivalent rare earth coordination of donor residues group organic ligand, it is characterized in that its structural formula is as follows:

In the said structure formula, Ln, X, R, R ¹, R ²With Q according to claim 1.

3, a class as claimed in claim 1 contains the bivalent rare earth coordination of donor residues group organic ligand, and its structural formula of its feature is as follows:

In the said structure formula, Ln, X, R, R ¹, R ²With L according to claim 1.

4, a kind of synthetic method that contains the bivalent rare earth coordination of donor residues group organic ligand as claimed in claim 1 is characterized in that

(1) in organic solvent, is by structural formula

Corresponding organic ligand and butyllithium, sodium Metal 99.5 or potassium metal mol ratio are 1: during 1-5, reacted 0.5-24 hour, temperature of reaction is-78 ℃～40 ℃;

(2) then the reaction product of (1) and Ln (II) I ₂The nTHF mol ratio is 1: during 0.5-5, reaction is 0.5-48 hour in organic solvent, and temperature of reaction is-78 ℃～40 ℃; Or the reaction product of (1) and Ln (III) Cl ₃Mol ratio is 1: during 0.5-4, reaction is 0.5-48 hour in organic solvent, and temperature of reaction is-78 ℃～40 ℃, and reaction product and sodium Metal 99.5 mol ratio are 1 then: during 0.5-5, reaction obtained in 2-48 hour under organic solvent neutralization-30-40 ℃ temperature;

N=0～4 wherein, A is-C _1-4The following substituted indenyl of alkyl, aryl, benzyl or structural formula: X, Ln, Z, R, R ¹Or R ²According to claim 1.

5, the synthetic method that contains the bivalent rare earth coordination of donor residues group organic ligand as claimed in claim 4 is characterized in that described organic solvent is tetrahydrofuran (THF), glycol dimethyl ether, sherwood oil, ether or toluene.

6, a kind of purposes that contains the bivalent rare earth coordination of donor residues group organic ligand as claimed in claim 1 is characterized in that being used for the polymerization of catalysis methyl methacrylate, caprolactone and valerolactone.