Preparation method of trimethoxy pentamethyl cyclopentadienyl titanium

Abstract

The invention relates to a preparation method of trimethoxy pentamethyl cyclopentadienyl titanium, which comprises the following steps: (1) vacuumizing a reactor for replacement, detecting the content of moisture and oxygen in gas in a reaction kettle by an instrument, and stopping vacuum replacement when the content is lower than 50ppm; (2) pentamethyl cyclopentadienyl titanium trichloride, ammonia and a solvent are added into a reactor, methanol is dropwise added into the reactor, a crude product trimethoxy pentamethyl cyclopentadienyl titanium is obtained through a reaction, the reaction temperature ranges from-30 DEG C to 50 DEG C, and the pressure ranges from-0.05 MPa to 0.05 MPa; (3) filtering and desalting the crude product trimethoxy pentamethyl cyclopentadienyl titanium obtained in the step (2) in an inert environment; and (4) the filtrate obtained in the step (3) is refined, pure trimethoxy pentamethyl cyclopentadienyl titanium is obtained, and the metal purity reaches 5N. Methanol is used as a raw material, the synthesis route can be shortened, the cost is reduced, and meanwhile, the material is relatively safe.

Description

Technical Field

[0001] The present invention relates to the fields of organic catalysts and semiconductor high-purity materials, and in particular to a method for preparing trimethoxypentamethylcyclopentadienyltitanium. Background Art

[0002] Pentamethylcyclopentadienyltitanium trimethoxide (NxTi) is a titanium-based precursor and an organic olefin polymerization catalyst. Pentamethylcyclopentadienyltitanium trimethoxide (CAS: 123927-75-3), also known as NxTi or star-Ti, is a titanium-based precursor material. NxTi is used in ALD, CVD, and PECVD processes. NxTi utilizes atomic layer deposition (ALD) to create titanium dioxide / titanium nitride thin films for DRAM manufacturing. NxTi is also used in glass, optics, and ceramics.

[0003] The widely reported synthesis route for trimethoxypentamethylcyclopentadienyltitanium involves reacting sodium methoxide with pentamethylcyclopentadienyltitanium trichloride to form trimethoxypentamethylcyclopentadienyltitanium. This reaction has two disadvantages: the sodium methoxide raw material must be synthesized separately, adding additional steps to the synthesis process; and the sodium methoxide and its synthetic raw materials are reactive and hazardous, increasing the risk of the synthesis process. Summary of the Invention

[0004] The purpose of the present invention is to provide a preparation method of trimethoxypentamethylcyclopentadienyl titanium, shorten the synthesis route of trimethoxypentamethylcyclopentadienyl titanium, select suitable raw materials and reduce the risk of the synthesis process.

[0005] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0006] A method for preparing trimethoxypentamethylcyclopentadienyl titanium comprises the following steps:

[0007] Step 1: Vacuum the reactor and replace it, and keep detecting the moisture and oxygen content in the gas in the reactor. Stop the replacement when the content is qualified;

[0008] Step 2: adding pentamethylcyclopentadienyltitanium trichloride, ammonia, and a solvent into a reactor, and adding methanol dropwise into the reactor to react to obtain a crude product of trimethoxypentamethylcyclopentadienyltitanium;

[0009] Step 3, filtering and desalting the crude trimethoxypentamethylcyclopentadienyltitanium obtained in step 2 under an inert environment to obtain a filtrate;

[0010] Step 4: purifying the filtrate obtained in step 3 to obtain trimethoxypentamethylcyclopentadienyltitanium.

[0011] Preferably, the qualified content in step 1 means that the moisture and oxygen contents inside the reactor are both lower than 50 ppm.

[0012] Preferably, the reaction temperature in step 2 is -30°C to 50°C, the pressure is -0.05 to 0.05 MPa, and the reaction time is 5 to 12 hours.

[0013] Preferably, the ammonia used in the reaction of step 2 is one or a combination of two or more of dimethylamine, diethylamine, triethylamine and ammonia.

[0014] Preferably, the solvent used in step 2 is a halogenated alkane organic solvent.

[0015] Preferably, the halogenated alkane organic solvent includes biphenyl solvents such as toluene, xylene, dichloromethane and chloroform.

[0016] Preferably, in step 2, the molar ratio of pentamethylcyclopentadienyltitanium trichloride, methanol, and ammonia added is 1-1.5:3-4.5:3-9, and the mass ratio of pentamethylcyclopentadienyltitanium trichloride to solvent is 1:10-20.

[0017] Preferably, the methanol is added dropwise for 0.2 to 0.5 h.

[0018] Preferably, the inert environment in step 3 includes a nitrogen environment, a helium environment and an argon environment.

[0019] Preferably, the refining in step 4 includes distilling at a temperature not higher than 100° C. to remove methanol, ammonia and solvent from the filtrate to obtain a crude product, filtering the crude product to remove solids precipitated by distillation, and then performing negative pressure distillation;

[0020] The negative pressure distillation has a distillation pressure of 1 to 10 torr and a distillation temperature of 110 to 150° C., and the purity of the product after distillation reaches 5N.

[0021] Preferably, the reactor is made of stainless steel, glass or enamel.

[0022] The application of the above invention technology has the following beneficial effects:

[0023] The present invention mainly provides a method for preparing trimethoxypentamethylcyclopentadienyl titanium. The method uses pentamethylcyclopentadienyl titanium trichloride with methanol and ammonia to prepare trimethoxypentamethylcyclopentadienyl titanium. The method has mild conditions and is easy to react. By using methanol as a raw material instead of sodium methoxide, the present invention reduces the risk of the reaction materials and the synthesis reaction. By using methanol instead of sodium methoxide, the synthesis step of sodium methoxide is omitted, shortening the synthesis route.

[0024] The invention provides a method for refining trimethoxypentamethylcyclopentadienyl titanium, and the purity of the product reaches 5N. DETAILED DESCRIPTION

[0025] Example 1

[0026] A method for preparing trimethoxypentamethylcyclopentadienyl titanium comprises the following steps:

[0027] Step 1: vacuum the reactor and detect the moisture and oxygen content in the gas in the reactor by instruments. When the moisture and oxygen content are lower than 50 ppm, stop vacuum replacement;

[0028] Step 2: 19.8 g of pentamethylcyclopentadienyltitanium trichloride, 21.9 g of triethylamine, and 260 g of toluene were added to a reactor, and 7.0 g of methanol was added dropwise to the reactor over 12 minutes to react to obtain crude trimethoxypentamethylcyclopentadienyltitanium. The reaction temperature was 25° C., the pressure was 0.05 MPa, and the reaction was carried out for 7 hours to obtain the product.

[0029] Step 3, filtering and desalting the crude trimethoxypentamethylcyclopentadienyl titanium obtained in step (2) under a nitrogen environment;

[0030] Step 4: The filtrate obtained in step (3) is refined and distilled at 80°C to remove most of the methanol, triethylamine, and solvent in the filtrate to obtain a crude product. The crude product is filtered to remove the solid precipitated by distillation, and then subjected to negative pressure distillation at a distillation pressure of 1 torr and a distillation temperature of 110°C to obtain pure trimethoxypentamethylcyclopentadienyltitanium with a yield of 79% and a metal purity of 5N.

[0031] 1 H NMR (400MHz, ppm, CDCl3): δ4.1(m,3OCH3),2.0(m,C5(CH3)5)

[0032] The pure product was tested by ICP-MS / MS, and the results are shown in Table 1.

[0033] Table 1

[0034]

[0035]

[0036] Example 2

[0037] A method for preparing trimethoxypentamethylcyclopentadienyl titanium comprises the following steps:

[0038] Step 1: vacuum the reactor and detect the moisture and oxygen content in the gas in the reactor by instruments. When the moisture and oxygen content are lower than 50 ppm, stop vacuum replacement;

[0039] Step 2: 19.8 g of pentamethylcyclopentadienyltitanium trichloride, 39.6 g of triethylamine, and 260 g of toluene are added to a reactor, and 7.0 g of methanol is added dropwise to the reactor over 18 minutes to react to obtain crude trimethoxypentamethylcyclopentadienyltitanium. The reaction temperature is 50° C. and the pressure is 0 MPa (at normal pressure). The product is obtained after reacting for 5 hours.

[0040] Step 3, filtering and desalting the crude trimethoxypentamethylcyclopentadienyl titanium obtained in step (2) under a helium environment;

[0041] Step 4: The filtrate obtained in step (3) is refined and distilled at 100° C. to remove most of the methanol, triethylamine, and solvent in the filtrate to obtain a crude product. The crude product is filtered to remove the solid precipitated by distillation, and then subjected to negative pressure distillation at a distillation pressure of 10 torr and a distillation temperature of 150° C. to obtain pure trimethoxypentamethylcyclopentadienyltitanium with a yield of 69% and a metal purity of 5N.

[0042] The pure product was tested by ICP-MS / MS, and the results are shown in Table 2.

[0043] Table 2

[0044]

[0045]

[0046] Example 3

[0047] A method for preparing trimethoxypentamethylcyclopentadienyl titanium comprises the following steps:

[0048] Step 1: vacuum the reactor and detect the moisture and oxygen content in the gas in the reactor by instruments. When the moisture and oxygen content are lower than 50 ppm, stop vacuum replacement;

[0049] Step 2: 19.8 g of pentamethylcyclopentadienyltitanium trichloride, 21.9 g of triethylamine, and 400 g of toluene are added to a reactor, and 7.0 g of methanol is added dropwise to the reactor over 30 minutes to react to obtain crude trimethoxypentamethylcyclopentadienyltitanium. The reaction temperature is -30°C and the pressure is -0.05 MPa. The product is obtained after reacting for 12 hours.

[0050] Step 3, filtering and desalting the crude trimethoxypentamethylcyclopentadienyl titanium obtained in step (2) under an argon environment;

[0051] Step 4: The filtrate obtained in step (3) is refined and distilled at 100° C. to remove most of the methanol, triethylamine, and solvent in the filtrate to obtain a crude product. The crude product is filtered to remove the solid precipitated by distillation, and then subjected to negative pressure distillation at a distillation pressure of 5 torr and a distillation temperature of 130° C. to obtain pure trimethoxypentamethylcyclopentadienyltitanium with a yield of 71% and a metal purity of 5N.

[0052] The pure product was tested by ICP-MS / MS, and the results are shown in Table 3.

[0053] Table 3

[0054] element Content ppb element Content ppb Al 4 Au 3 Sb 5 Hf 21 As 4 Fe 6 Ba 1 Pb 3 Be 1 Li 4 B 8 Mg 1 Cd 7 Mn 1 Ca 1 Ni 1 Cr 1 K 1 Co 1 Ag 7 Cu 1 Na 6 Ga 2 Sr 4 Ge 2 Th 1 Sn 6 U 1 V 5 Zn 4 Zr 50

[0055] Comparative Example 1

[0056] The difference between this comparative example and Example 1 is that: in step 2, the feeding ratio is changed, and the mass ratio of pentamethylcyclopentadienyltitanium trichloride:triethylamine is 1.5:1;

[0057] The yield of pure trimethoxypentamethylcyclopentadienyltitanium is 48%, and the metal purity reaches 5N.

[0058] Comparative Example 2

[0059] The difference between this comparative example and Example 1 is that: Step 2: the reaction parameters are changed, the reaction temperature is 60°C, and the pressure is -0.10 MPa;

[0060] The yield of pure trimethoxypentamethylcyclopentadienyltitanium was 32%, and the metal purity did not reach 5N.

[0061] Comparative Example 3

[0062] The difference between this comparative example and Example 1 is that: Step 4: distillation parameters are changed, the material distillation parameters are distillation pressure 1 torr, and distillation temperature 180°C.

[0063] The yield of pure trimethoxypentamethylcyclopentadienyltitanium was 43%, and the metal purity did not reach 5N.

[0064] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing trimethoxypentamethylcyclopentadienyl titanium, characterized in that: The steps include: Step 1: Vacuum the reactor and replace it, and keep detecting the moisture and oxygen content in the gas in the reactor. Stop the replacement when the content is qualified; Step 2: adding pentamethylcyclopentadienyltitanium trichloride, ammonia, and a solvent into a reactor, and adding methanol dropwise into the reactor to react to obtain a crude product of trimethoxypentamethylcyclopentadienyltitanium; Step 3, filtering and desalting the crude trimethoxypentamethylcyclopentadienyltitanium obtained in step 2 under an inert environment to obtain a filtrate; Step 4: purifying the filtrate obtained in step 3 to obtain trimethoxypentamethylcyclopentadienyltitanium.

2. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The qualified content in step 1 means that the moisture and oxygen contents inside the reactor are both lower than 50 ppm.

3. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The reaction temperature of step 2 is -30°C to 50°C, the pressure is -0.05 to 0.05 MPa, and the reaction time is 5 to 12 hours.

4. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The ammonia used in the reaction of step 2 is one or a combination of two or more of dimethylamine, diethylamine, triethylamine and ammonia gas.

5. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The solvent used in step 2 is a halogenated alkane organic solvent.

6. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 5, wherein: Halogenated alkane organic solvents include biphenyl solvents such as toluene, xylene, dichloromethane and chloroform.

7. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: In step 2, the molar ratio of pentamethylcyclopentadiene titanium trichloride, methanol, and ammonia is 1-1.5:3-4.5:3-9, and the mass ratio of pentamethylcyclopentadiene titanium trichloride to solvent is 1:10-20; The addition time of methanol is 0.2 to 0.5 h.

8. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The inert environment in step 3 includes a nitrogen environment, a helium environment and an argon environment.

9. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The refining in step 4 includes distilling at a temperature not higher than 100° C. to remove methanol, ammonia and solvent from the filtrate to obtain a crude product, filtering the crude product to remove the solid precipitated by distillation, and then performing negative pressure distillation; The negative pressure distillation has a distillation pressure of 1 to 10 torr and a distillation temperature of 110 to 150° C., and the purity of the product after distillation reaches 5N.

10. The method for preparing trimethoxypentamethylcyclopentadienyl titanium according to claim 1, wherein: The reactor is made of stainless steel, glass or enamel.

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