Process for preparation of dialkylaluminium alkanolates
Through the combination of flow chemical technology and static mixer, the problem of difficult reaction control between trialkylaluminum and aluminum alkanolate is solved, and the stable preparation of dialkylaluminum alkanolate is achieved, and the purity and yield of the product are improved. The problems of reaction control and scale expansion in the prior art have been overcome.
Patent Information
- Application Number
- CN202380034849.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-03-16
- Filing Date
- 2023-03-14
- Publication Date
- 2024-12-13
AI Technical Summary
The prior art faces difficulties in controlling the reaction caused by the spontaneous ignition properties of trialkylaluminum substances and low boiling points when preparing dialkylaluminum alkanols. The reaction is highly exothermic, resulting in poor mixing and local hot spots, making it difficult to expand the scale.
Using flow chemistry technology combined with static mixer, the reaction temperature is controlled between 10°C and 95°C by mixing trialkylaluminum and aluminum alkanolate in a non-coordinating solvent, using a non-coordinating solvent such as n-pentane or benzene, etc., to ensure reaction equilibrium and exothermic control.
A method of robust preparation of dialkylaluminum alkoxides is realized, which improves the purity and yield of the product, overcomes the difficulties of reaction control and scale-up, and ensures the superiority of the product.
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Figure CN119137129A_ABST
Abstract
Description
Technical Field
[0001] The present invention generally relates to methods for preparing dialkylaluminum alkoxides, such as dimethylaluminum isopropoxide. Background Art
[0002] Dialkylaluminum alkoxides can be used as precursors for depositing aluminum oxide films. Current methods for preparing such compounds (e.g., dimethylaluminum isopropoxide (CAS No. 6063-89-4)) include the reaction of trialkylaluminum species with various alcohols at very low temperatures, or the direct reaction of trialkylaluminum species with aluminum alkoxides.
[0003] One difficulty in synthesizing such compounds is the pyrophoric nature of trialkylaluminum materials and their relatively low boiling points. In addition, aluminum alkoxides such as aluminum isopropoxide are solids. The reaction of trialkylaluminum materials such as trimethylaluminum with solid aluminum isopropoxide is further problematic because the reaction is highly exothermic, thus requiring the slow addition of trimethylaluminum. Even so, the reaction mixture mixes poorly and often encounters local hot spots. Therefore, an improved method for preparing such materials would be of great interest, which would withstand scale-up to the kilogram scale. Summary of the invention
[0004] In summary, the present invention provides a robust method for preparing dialkylaluminum alkoxides (such as dimethylaluminum isopropoxide). In one embodiment, flow chemistry techniques are combined with at least one static mixer to provide the desired compound in good yield. Generally speaking, the present invention provides a method for preparing a compound of formula (I):
[0005] (R)2Al-OR 1 (I)
[0006] wherein each R is independently selected from a C1-C8 alkyl group or a phenyl group, and R 1 is a C1-C8 alkyl group;
[0007] The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula Al(OR 1 )3 Compound or formula HOR 1 A solution of the compound and a non-coordinating solvent is mixed. BRIEF DESCRIPTION OF THE DRAWINGS
[0008] Figure 1 A simplified flow chart of one embodiment of operating the process. A trialkylaluminum starting material (1) and an aluminum alkoxide (2) are combined in at least one static mixer (3) and allowed to react via a flow reaction. The product (4) contained in a solvent is then collected and purified. DETAILED DESCRIPTION
[0009] As used in this specification and the following claims, the singular forms "a", "an", and "the" include plural references unless the content clearly dictates otherwise. As used in this specification and the following claims, the term "or" is generally employed in its sense including "and / or" unless the content clearly dictates otherwise.
[0010] The term "about" generally refers to a range of values that are considered equivalent to the recited value (eg, having the same function or result). In many instances, the term "about" may include values that are rounded to the nearest significant figure.
[0011] The recitation of numerical ranges using endpoints includes all numbers subsumed within that range (eg, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
[0012] In a first aspect, the present invention provides a method for preparing a compound of formula (I):
[0013] (R)2Al-OR 1 (I)
[0014] wherein each R is independently selected from a C1-C8 alkyl group or a phenyl group, and R 1 is a C1-C8 alkyl group;
[0015] The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula Al(OR 1 )3 A solution of the compound and a non-coordinating solvent is mixed.
[0016] In this method, exemplary C1-C8 alkyl groups include straight chain and branched chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, and the like.
[0017] In certain embodiments, R and R 1 Independently selected from C1-C4 alkyl.
[0018] In one embodiment, the compound of formula (I) is dimethyl aluminum isopropoxide. The compound of formula (I) above is represented by the empirical formula (R)2Al-OR 1 In other words, aluminum dimethyl isopropoxide will be represented as follows:
[0019]
[0020] Non-coordinating solvents are those solvents that do not react with the starting material, i.e., any of the trialkylaluminum species or aluminum alkoxide or the product of formula (I). In one embodiment, the non-coordinating solvent has a maximum boiling point of about 95° C. at atmospheric pressure. Exemplary non-coordinating solvents include hydrocarbons having 5 to 8 carbon atoms along with certain aromatic compounds optionally substituted with C1-C8 alkyl groups. Exemplary non-coordinating solvents include n-pentane, isopentane, n-hexane, n-heptane, n-octane, cyclohexane, benzene, toluene, xylene, and mixtures thereof.
[0021] Exemplary compounds of formula (I) include those wherein R and R 1 Such as those set out in Table 1 below.
[0022] Table 1.
[0023]
[0024]
[0025] Before the combined reaction, the starting material (R)3Al and the starting material Al(OR 1 )3 are each dissolved in such non-coordinating solvents. Advantageously, the concentration of each is high enough to ensure a rapid and mild reaction while balancing the ability to control the exothermic reaction. In certain embodiments, the starting material is present in a concentration of about 0.2M to about 5.0M in the non-coordinating solvent. For example, the compound of formula (R)3A1 is dissolved in a concentration of about 0.5 to about 5.0M in the non-coordinating solvent. In some embodiments, the compound of formula Al(OR 1 )3 compound is dissolved in a non-coordinating solvent at a concentration of about 0.2 to about 4.0 M. In another embodiment, the formula Al(OR 1 )3 The compound is dissolved in the non-coordinating solvent, but is added as a neat liquid, or as a pure substance in the liquid phase.
[0026] The following table illustrates the favorable ranges within which a flow reactor can be utilized to migrate reaction exotherms along with process plugging.
[0027] Table 2.
[0028] <![CDATA[Aluminum (isopropoxide) 3 solution]]> 1.5 wt% 0.05M 15 wt% 0.6M 50% by weight 3.3M
[0029] Table 3.
[0030] TMA (trimethylaluminum) solution 1.5 wt% 0.14M 20% by weight 1.9M 50% by weight 5.0M
[0031] Table 4.
[0032] Isopropyl alcohol solution 1.5 wt% 0.18M 16 wt% 1.6M 50% by weight 6.1M
[0033] When combined, the starting materials reactants R-Al and Al(OR 1Advantageously, the reaction is carried out at a temperature of about 10°C to about 95°C.
[0034] Additionally, in one embodiment, one or more static mixers are utilized. If more than one is utilized, the mixers may be connected in series to facilitate mixing and reaction of the starting materials. Such static mixers are widely commercially available, for example, from McMaster-Carr (www.mcmaster.com). In some embodiments, mixing is performed at a temperature greater than about 10°C.
[0035] In another embodiment, the starting material of formula (R) 3A1 is distilled at atmospheric pressure or reduced pressure before use. In another embodiment, the starting material of formula (R) 3A1 is distilled at atmospheric pressure or reduced pressure before use. 1 )3 Compound filtration.
[0036] In certain embodiments, the method is carried out at a temperature of about 5° C. to about 95° C., or about 10° C. to about 40° C. In this regard, the starting materials may be utilized at room temperature and the apparatus may be operated within the detailed temperature ranges.
[0037] Once the product of formula (I) is collected (eg Figure 1 As described in (4)), it can be further purified by removing the solvent and distilling.
[0038] In another aspect, the compound of formula (I) can be prepared from a solution comprising a compound of formula (R)3A1 and a non-coordinating solvent and a solution comprising a compound of formula HOR 1 A solution of the compound and a non-coordinating solvent is prepared. In this regard, the exemplary formula HOR 1 Compounds include methanol, ethanol, n-propanol, isopropanol and the like.
[0039] The dialkylaluminum alkoxide compounds of formula (I) will have a limited amount of residual non-coordinating solvent present after purification. Therefore, in another aspect, the present invention provides compounds of formula (I):
[0040] (R)2Al-OR 1 (I)
[0041] wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; wherein the compound contains about 20 to about 2000 ppm of a non-coordinating solvent.
[0042] In some embodiments, the compound comprises a non-coordinating solvent in a range of about 20 ppm to about 2000 ppm, about 50 ppm to about 2000 ppm, about 100 ppm to about 2000 pm, about 250 ppm to about 2000 ppm, about 20 ppm to about 1500 ppm, about 50 ppm to about 1500 ppm, about 100 ppm to about 1500 ppm, about 250 ppm to about 1500 ppm, about 20 ppm to about 1000 ppm, about 50 ppm to about 1000 ppm, about 100 ppm to about 1000 ppm, about 250 ppm to about 1000 ppm, and all ranges and sub-ranges therebetween.
[0043] To the extent that the process of the present invention overcomes many of the problems of previous processes, it is also found that the product of formula (I) has superior purity. Therefore, in another aspect, the present invention provides a compound of formula (I):
[0044] (R)2Al-OR 1 (I)
[0045] wherein each R is independently selected from a C1-C3 alkyl group, and R 1 is a C1-C3 alkyl group; wherein the compound comprises no more than about 1200 ppm of a trimer or tetramer of a compound of formula (I) and / or no more than about 2500 ppm of a combined trimer / tetramer of a compound of formula (I).
[0046] In some embodiments, the compound comprises no more than about 1200ppm, about 1000ppm, about 900ppm, about 800ppm, or about 700ppm of a trimer or tetramer of a compound of formula (I). In some embodiments, the compound may also comprise no more than about 2500ppm, about 2250ppm, about 2000ppm, about 1750ppm, about 1500ppm, or about 1250ppm of a combined trimer and tetramer of a compound of formula (I).
[0047] In one embodiment of this aspect, the compound of formula (I) is dimethylaluminum isopropoxide.
[0048] In another embodiment, the present invention provides a method for preparing a compound of formula (II):
[0049] (R)Al-(OR 1 )2(II),
[0050] wherein each R is independently selected from a C1-C8 alkyl group or a phenyl group, and R 1 is a C1-C8 alkyl group;
[0051] The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula Al(OR 1 )3 A solution of the compound and a non-coordinating solvent is mixed.
[0052] Non-coordinating solvents suitable for use in the process of producing compounds of Formula II are described above for compounds of Formula I. Exemplary compounds of Formula (II) include those wherein R and R 1 The same as those described above for compounds of formula I. Aspects of the present invention allow for adjustment of the molar stoichiometry to specifically isolate compounds of formula (II).
[0053] In one embodiment, the compound of formula (II) is diethoxyethylaluminum.
[0054] The following examples further illustrate the invention but, of course, should not be construed as limiting the scope of the invention in any way.
[0055] Example 1
[0056] Aluminum isopropoxide (445 g, 2.18 mol, 1.05 equiv.) was placed in a 5 L container and dissolved in 2.5 kg heptane to produce a 15 wt % solution. Trimethylaluminum (300 g, 4.16 mol, 1.00 equiv.) was placed in a 5 L container and diluted with 1.2 kg heptane to produce a 20 wt % solution. Both containers were connected to a flow reactor containing: two needle nose valves, two static mixers, a 3 ft coil and 2 temperature probes; and a 12 L receiving container. Both room temperature solutions flowed through the reactor, maintaining the temperature between 20°C and 40°C. An increased temperature relative to ambient temperature was observed at the two temperature probes, indicating a reaction. The samples were withdrawn immediately after the flowing solutions were completed. 1 The H NMR spectrum showed complete conversion to dimethylaluminum isopropoxide (89% crude purity) with no trimethylaluminum remaining. Removal of the solvent at 50° C. and distillation of the product under vacuum at 60° C. gave a clear, colorless solution of dimethylaluminum in 75% yield. The trimer content was determined to be 400 ppm and the tetramer content was determined to be 1200 ppm. The results confirm that the compound of formula (I) can be obtained with no more than about 1200 ppm of trimer or tetramer of the compound of formula (I) and no more than about 2500 ppm of combined trimer / tetramer of the compound of formula (I).
[0057] Example 2
[0058] Aluminum isopropoxide (445 g, 2.18 mol, 1.05 equiv.) was placed in a 5 L container and dissolved in 2.5 kg of heptane to produce a 15 wt % solution. The aluminum isopropoxide was filtered through a glass frit into another 5 L container. Trimethylaluminum (300 g, 4.16 mol, 1.00 equiv.) was placed in a 5 L container and diluted with 1.2 kg of heptane to produce a 20 wt % solution. The two containers were connected to a simplified flow reactor containing: two needle nose valves, two static mixers, a 3 ft coil and 2 temperature probes to a 12 L receiving container. Both room temperature solutions flowed through the reactor, maintaining the temperature between 20° C. and 40° C. An increase in temperature relative to ambient temperature was observed at the two temperature probes, indicating a reaction. The samples were withdrawn immediately after the flowing solutions were completed. 1 The H NMR spectrum showed complete conversion to dimethylaluminum isopropoxide (88% crude purity) with no trimethylaluminum remaining. Removal of the solvent at 50° C. and distillation of the product under vacuum at 60° C. gave a clear, colorless solution of dimethylaluminum in 75% yield. The trimer content was determined to be 170 ppm and the tetramer content was determined to be 490 ppm. The results confirm that the compound of formula (I) can be obtained with no more than about 1200 ppm of trimer or tetramer of the compound of formula (I) and no more than about 2500 ppm of combined trimer / tetramer of the compound of formula (I).
[0059] Example 3
[0060] Isopropanol (6.1 g, 0.10 mol, 1.02 equiv.) was placed in a 50 mL container and diluted in 43 mL of heptane to produce a 15 wt % solution. Trimethylaluminum (2.0 M, 50 mL, 0.10 mol, 1.00 equiv.) was placed in a 50 mL container. Both containers were connected to a simplified flow reactor containing: a static mixer, a 3 ft coil, and 2 temperature probes to a 500 mL receiving vessel. Both room temperature solutions flowed through the reactor, maintaining the temperature between 25°C and 85°C. A higher temperature was observed at the first temperature probe, indicating a reaction. The sample was withdrawn immediately after the flowing solution was completed. 1 H NMR spectroscopy showed 98% conversion to dimethylaluminum isopropoxide (95% crude purity) with 2% trimethylaluminum remaining.
[0061] Example 4
[0062] Trimethylaluminum (2.0 M, 5 mL, 0.01 mol, 1.00 equiv.) in heptane was placed in a 40 mL vial containing a stir bar. Ethanol (0.46 g, 0.01 mol, 1.0 equiv.) as a 20 wt % solution in heptane was slowly added to the trimethylaluminum over 5 minutes while stirring, gas was observed. The reaction temperature was maintained between 25° C. and 85° C. After the addition was complete, the sample was withdrawn immediately. 1 H NMR spectroscopy showed 85% conversion to dimethylaluminum ethoxide, with 5% trimethylaluminum remaining.
[0063] Example 5
[0064] Trimethylaluminum (2.0 M, 5 mL, 0.01 mol, 1.00 equiv.) in heptane was placed in a 40 mL vial containing a stir bar. Methanol (0.32 g, 0.01 mol, 1.0 equiv.) as a 20 wt % solution in heptane was slowly added to the trimethylaluminum over 5 minutes while stirring, gas was observed. The reaction temperature was maintained between 25° C. and 85° C. After the addition was complete, the sample was withdrawn immediately. 1 H NMR spectroscopy showed 76% conversion to dimethylaluminum methoxide, with 19% trimethylaluminum remaining.
[0065] The conversion rate value is 1 H NMR spectroscopy was determined using a 400mHz Burker instrument. The purity profile was determined by gas chromatography (Agilent 7890B and 5977 quadruple MSD). Separation was achieved on a GC column. After exit, the molecule was ionized using electron impact ionization (70eV). The MSD collected a full mass spectrum (10 to 700amu) approximately once per second.
[0066] Aspects of the Invention
[0067] In a first aspect, the present invention provides a method for preparing a compound of formula (I):
[0068] (R)2Al-OR 1 (I)
[0069] wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group;
[0070] The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula Al(OR 1 )3 A solution of the compound and a non-coordinating solvent is mixed.
[0071] In a second aspect, the present invention provides a method for preparing a compound of formula (I):
[0072] (R)2Al-OR 1 (I)
[0073] wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group;
[0074] The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula HOR 1 A solution of the compound and a non-coordinating solvent is mixed.
[0075] In a third aspect, the present invention provides a method according to the first or second aspect, wherein R is selected from methyl, ethyl, n-propyl and isopropyl.
[0076] In a fourth aspect, the present invention provides a method according to the first, second or third aspect, wherein R 1 Selected from methyl, ethyl, n-propyl and isopropyl.
[0077] In a fifth aspect, the present invention provides a method according to any one of the first to fourth aspects, wherein the compound of formula (I) is dimethylaluminum isopropoxide.
[0078] In a sixth aspect, the present invention provides a method according to any one of the first to fifth aspects, wherein the mixing is performed in a static mixer.
[0079] In a seventh aspect, the present invention provides a method according to any one of aspects 1 to 6, wherein the non-coordinating solvent is selected from hydrocarbons having 5 to 8 carbon atoms.
[0080] In an eighth aspect, the present invention provides a method according to the seventh aspect, wherein the non-coordinating solvent is selected from n-hexane and n-heptane.
[0081] In a ninth aspect, the present invention provides a method according to any one of aspects 1 to 7, wherein the non-coordinating solvent is selected from benzene, toluene and xylene.
[0082] In a tenth aspect, the present invention provides a method according to any one of aspects 1 to 9, wherein the mixing is performed at a temperature greater than about 10°C.
[0083] In an eleventh aspect, the present invention provides a method according to any one of aspects one to nine, wherein the mixing is performed at a temperature of about 10°C to about 95°C.
[0084] In a twelfth aspect, the present invention provides a method according to any one of aspects 1 to 9, wherein the mixing is performed at a temperature of about 10°C to about 40°C.
[0085] In a thirteenth aspect, the present invention provides a method according to any one of the first to twelfth aspects, wherein the mixing is performed in two or more static mixers connected in series.
[0086] In a fourteenth aspect, the present invention provides a method according to any one of aspects 1 to twelfth, wherein the compound of formula (R) 3 Al is dissolved in a non-coordinating solvent at a concentration of about 0.5 to about 5.0 M.
[0087] In a fifteenth aspect, the present invention provides a method according to any one of the first or third to fourteenth aspects, wherein the formula Al(OR 1 )3 compound is dissolved in a non-coordinating solvent at a concentration of about 0.2 to about 4.0 M.
[0088] In a sixteenth aspect, the present invention provides a method according to any one of the first to fifteenth aspects, further comprising the step of distilling the compound of formula (R) 3 Al before use.
[0089] In a seventeenth aspect, the present invention provides a method according to the first or third to sixteenth aspects, further comprising converting the formula Al(OR 1 )3 Compound filtering step.
[0090] In an eighteenth aspect, the present invention provides a compound of formula (I):
[0091] (R)2Al-OR 1 (I)
[0092] wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; wherein the compound contains from about 20 to about 2000 ppm of a non-coordinating solvent.
[0093] In a nineteenth aspect, the present invention provides a compound according to the eighteenth aspect, wherein the compound of formula (I) is dimethylaluminum isopropoxide.
[0094] In a twentieth aspect, the present invention provides a compound of formula (I):
[0095] (R)2Al-OR 1 (I)
[0096] wherein each R is independently selected from a C1-C3 alkyl group, and R 1is a C1-C3 alkyl group; wherein the compound comprises no more than about 1200 ppm of a trimer or tetramer of a compound of formula (I) and / or no more than about 2500 ppm of a combined trimer / tetramer of a compound of formula (I).
[0097] In a twenty-first aspect, the present invention provides a compound according to the twentieth aspect, wherein the compound of formula (I) is dimethylaluminum isopropoxide.
[0098] In a twenty-second aspect, the present invention provides a compound of formula (I):
[0099] (R)2Al-OR 1 (I)
[0100] wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group, which is prepared by the method according to any one of the first to seventeenth aspects.
[0101] In a twenty-third aspect, the present invention provides the compound according to the twenty-second aspect, which is dimethylaluminum isopropoxide.
[0102] In a twenty-fourth aspect, the present invention provides a method for preparing a compound of formula (I):
[0103] (R)2Al-OR 1 (I)
[0104] wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; the method comprises: (i) a solution containing a compound of formula (R) 3Al and a non-coordinating solvent and (ii) a compound of formula Al (OR 1 )3 compounds are mixed.
[0105] Having thus described several illustrative embodiments of the present invention, it will be readily apparent to those skilled in the art that still other embodiments may be made and used within the scope of the claims appended hereto. The many advantages of the present invention covered by this document have been set forth in the foregoing description. However, it will be appreciated that the present invention is in many respects merely illustrative. Of course, the scope of the present invention is defined in the language of the appended claims.
Claims
1. A method for preparing a compound of formula (I), (R)2Al-OR 1 (I), wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula Al(OR 1 )3 A solution of the compound and a non-coordinating solvent is mixed.
2. A method for preparing a compound of formula (I), (R)2Al-OR 1 (I), wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a solution comprising a compound of formula HOR 1 A solution of the compound and a non-coordinating solvent is mixed.
3. The method according to claim 1 or 2, wherein R is selected from methyl, ethyl, n-propyl and isopropyl.
4. The method according to any one of claims 1 to 3, wherein R 1 Selected from methyl, ethyl, n-propyl and isopropyl.
5. The process according to any one of claims 1 to 4, wherein the compound of formula (I) is dimethylaluminum isopropoxide.
6. The method according to any one of claims 1 to 5, wherein the mixing is performed in a static mixer.
7. The process according to any one of claims 1 to 6, wherein the non-coordinating solvent is selected from hydrocarbons having 5 to 8 carbon atoms.
8. The process according to claim 7, wherein the non-coordinating solvent is selected from n-hexane and n-heptane and isomers thereof.
9. The process of any one of claims 1 to 6, wherein the non-coordinating solvent is selected from benzene, toluene and xylene.
10. The process according to claims 1 to 6, wherein the non-coordinating solvent is selected from heavier high boiling hydrocarbons having 12 to 18 carbon atoms.
11. The process of claim 10, wherein the non-coordinating solvent is selected from the hydrocarbons n-dodecane and n-tetradecane and isomers thereof.
12. The process of claims 1 to 6, wherein the non-coordinating solvent is a mixture of high boiling hydrocarbons such as isoparaffin fluids.
13. The method of any one of the preceding claims, wherein the mixing is performed at a temperature greater than about 10°C.
14. The method of any one of the preceding claims, wherein the mixing is performed at a temperature of about 10°C to about 95°C.
15. The method according to any one of the preceding claims, wherein the mixing is carried out at a temperature of about 10°C to about 40°C.
16. The method according to any one of the preceding claims, wherein the mixing is performed in two or more static mixers connected in series.
17. The method of any one of the preceding claims, wherein the compound of formula (R)3A1 is dissolved in a non-coordinating solvent at a concentration of about 0.5 to about 5.0 M.
18. A method according to any one of the preceding claims, wherein the formula Al(OR 1 )3 compound is dissolved in a non-coordinating solvent at a concentration of about 0.2 to about 4.0 M.
19. A process according to any one of the preceding claims, further comprising the step of distilling the compound of formula (R) 3 Al prior to use.
20. The method according to claim 1 further comprises filtering the formula Al(OR 1 )3 steps of the compound.
21. A compound of formula (I), (R)2Al-OR 1 (I), wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; wherein the compound contains from about 20 to about 2000 ppm of a non-coordinating solvent.
22. The compound according to claim 21, wherein the compound of formula (I) is dimethylaluminum isopropoxide.
23. A compound of formula (I), (R)2Al-OR 1 (I), wherein each R is independently selected from a C1-C3 alkyl group, and R 1 is a C1-C3 alkyl group; wherein the compound contains no more than about 1200 ppm of a trimer or tetramer of a compound of formula (I) and / or no more than about 2500 ppm of a combined trimer / tetramer of a compound of formula (I).
24. The compound according to claim 23, wherein the compound of formula (I) is dimethylaluminum isopropoxide.
25. A method for preparing a compound of formula (I), (R)2Al-OR 1 (I), wherein each R is independently selected from a C1-C8 alkyl group, and R 1 is a C1-C8 alkyl group; The method comprises mixing (i) a solution comprising a compound of formula (R)3Al and a non-coordinating solvent with (ii) a compound of formula Al(OR)3Al without a solvent. 1 )3 compounds are mixed.
26. The compound according to claim 25, wherein the compound of formula (I) is dimethylaluminum isopropoxide.