Yttrium complexes and related methods

Abstract

Yttrium complexes and related methods are provided. A method of making an yttrium complex comprising contacting a metal alkyl cyclopentadienyl compound with an yttrium trihalide compound in a non-coordinating solvent to obtain a tris (alkyl cyclopentadienyl) yttrium complex. A composition includes a tris (alkylcyclopentadienyl) yttrium complex.

Description

Technical Field

[0001] The present disclosure relates to yttrium complexes and related methods. Background Art

[0002] Conventional synthesis of yttrium complexes involves multiple steps, which result in reduced yield and purity of the yttrium complex. Summary of the Invention

[0003] Some embodiments relate to a composition. In some embodiments, the composition comprises a complex of the formula:

[0004]

[0005] in:

[0006] R 1 and R 2 are each independently hydrogen or alkyl;

[0007] wherein the complex has 1 At least 70% purity as determined by H NMR;

[0008] The complex is a non-sublimed product.

[0009] Some embodiments relate to methods of forming a complex. In some embodiments, the method comprises contacting a metal alkylcyclopentadienyl compound with a yttrium trihalide compound in a non-coordinating solvent to obtain a tris(alkylcyclopentadienyl)yttrium complex. In some embodiments, the method comprises removing at least a portion of the non-coordinating solvent to obtain the tris(alkylcyclopentadienyl)yttrium complex in a solid phase. In some embodiments, the method comprises recrystallizing the tris(alkylcyclopentadienyl)yttrium complex. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Some embodiments of the present disclosure are described herein by way of example only and with reference to the accompanying drawings. With reference now to the specific drawings in detail, it should be emphasized that the embodiments shown are by way of example and for purposes of illustrative discussion of the embodiments of the present disclosure. In this regard, the description taken in conjunction with the accompanying drawings will provide those skilled in the art with an understanding of how the embodiments of the present disclosure may be practiced.

[0011] Figure 1 is a flow chart of a method for preparing a yttrium complex according to some embodiments. DETAILED DESCRIPTION

[0012] Among the benefits and improvements disclosed, other objects and advantages of the present disclosure will become apparent from the following description taken in conjunction with the accompanying drawings. Detailed embodiments of the present disclosure are disclosed herein; however, it should be understood that the disclosed embodiments are merely illustrative of the present disclosure that can be embodied in various forms. Furthermore, each example given of various embodiments of the present disclosure is intended to be illustrative and not restrictive.

[0013] Any prior patents and publications cited herein are hereby incorporated by reference in their entirety.

[0014] Throughout the specification and claims, unless the context clearly dictates otherwise, the following terms have the meanings explicitly associated herein. As used herein, the phrases "in one embodiment," "in an embodiment," and "in some embodiments" do not necessarily refer to the same embodiment, but they may. Furthermore, as used herein, the phrases "in another embodiment" and "in some other embodiments" do not necessarily refer to different embodiments, but they may. All embodiments of the present disclosure are intended to be combinable without departing from the scope or spirit of the present disclosure.

[0015] As used herein, unless the context clearly dictates otherwise, the term "based on" is not exclusive and allows for being based on other factors not described. Additionally, throughout the specification, the meanings of "a," "an," and "the" include plural referents. The meaning of "in" includes "in" and "on."

[0016] As used herein, the term "alkyl" refers to a hydrocarbon having from 1 to 30 carbon atoms. An alkyl group having n carbon atoms may be designated as "C n Alkyl groups are designated as C1-C3 alkyl groups. For example, "C3 alkyl" may include n-propyl and isopropyl. Alkyl groups having a range of carbon atoms (e.g., 1 to 30 carbon atoms) may be designated as C1-C3 alkyl groups. 30 In some embodiments, the alkyl group is a straight chain. In some embodiments, the alkyl group is branched. In some embodiments, the alkyl group is substituted. In some embodiments, the alkyl group is unsubstituted. In some embodiments, the alkyl group comprises at least one of the following: C1-C 10 Alkyl, C1-C9 alkyl, C1-C8 alkyl, C1-C7 alkyl, C1-C6 alkyl, C1-C5 alkyl, C1-C4 alkyl, C1-C3 alkyl, C1-C2 alkyl, C2-C 10 Alkyl, C3-C 10 Alkyl, C4-C 10 Alkyl, C5-C 10 Alkyl, C6-C 10 Alkyl, C7-C 10 Alkyl, C8-C10 alkyl, C2-C9 alkyl, C2-C8 alkyl, C2-C7 alkyl, C2-C6 alkyl, C2-C5 alkyl, C3-C5 alkyl, or any combination thereof. In some embodiments, the alkyl group includes at least one of the following: C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, C9 alkyl, C 10 Alkyl or any combination thereof. In some embodiments, alkyl includes at least one of the following: methyl, ethyl, n-propyl, 1-methylethyl (isopropyl), n-butyl, isobutyl, sec-butyl, n-pentyl, 1,1-dimethylethyl (tert-butyl), n-pentyl, isopentyl, n-hexyl, isohexyl, 3-methylhexyl, 2-methylhexyl, heptyl, octyl, nonyl, decyl, dodecyl, octadecyl or any combination thereof. In some embodiments, alkyl does not include a C2 alkyl group (e.g., ethyl).

[0017] As used herein, the term "halide" refers to -Cl, -Br, -I, or -F.

[0018] As used herein, the term "non-sublimation product" refers to a product that is not a product of a process in which matter transitions directly from a solid phase to a gas phase. In some embodiments, the non-sublimation product is a product that has the properties of a non-sublimation complex.

[0019] Conventional synthesis of yttrium complexes, such as tris(alkylcyclopentadienyl)yttrium(III) complexes, requires multiple steps to purify the product. For example, conventional synthetic routes utilize tetrahydrofuran. The tetrahydrofuran coordinates to the yttrium complex and must be removed through a series of extraction and sublimation steps. The extraction and sublimation steps have the disadvantages of reducing reaction yields and requiring a more complex synthesis method.

[0020] Provided herein are embodiments that overcome the difficulties and shortcomings of conventional synthesis and yttrium complexes prepared according to conventional synthesis. Some embodiments provide methods for synthesizing yttrium complexes, which are achieved by contacting a metal alkylcyclopentadienyl compound with a trihalide yttrium compound in a non-coordinating solvent to obtain a tri(alkylcyclopentadienyl)yttrium complex. In some embodiments, the methods disclosed herein do not involve the use of tetrahydrofuran. In some embodiments, the methods disclosed herein can achieve high yields and high purity, without requiring any extraction step and / or sublimation step to purify the resulting complex. Therefore, in some embodiments, the methods disclosed herein provide a simple one-step synthetic route for producing yttrium complexes.

[0021] Figure 1 is a flow chart of a method 100 for preparing a yttrium complex according to some embodiments.

[0022] At step 102 , in some embodiments, method 100 includes contacting a cyclopentadienyl compound with a yttrium trihalide compound in a non-coordinating solvent to obtain a yttrium complex.

[0023] In certain embodiments, contact includes direct contact or direct or close proximity of at least one of a cyclopentadienyl compound, a yttrium trihalide compound, a non-coordinating solvent, or any combination thereof. In certain embodiments, contact includes adding a cyclopentadienyl compound, a yttrium trihalide compound, and a non-coordinating solvent to a reaction vessel (e.g., a container, a flask, a vial, etc.) in any order. In certain embodiments, contact includes combining a cyclopentadienyl compound, a yttrium trihalide compound, and a non-coordinating solvent in a reaction vessel in any order. In certain embodiments, contact includes loading a cyclopentadienyl compound, a yttrium trihalide compound, and a non-coordinating solvent into a reaction vessel in any order. In certain embodiments, contact includes stirring a cyclopentadienyl compound, a yttrium trihalide compound, and a non-coordinating solvent. In certain embodiments, contact includes mixing a cyclopentadienyl compound, a yttrium trihalide compound, and a non-coordinating solvent. In certain embodiments, contact includes reacting a cyclopentadienyl compound, a yttrium trihalide compound, and a non-coordinating solvent.

[0024] In some embodiments, the contacting is carried out at or to a temperature in the range of 20°C to 150°C, or any range or sub-range therebetween. In some embodiments, the contacting is carried out at or to a temperature of 20°C to 140°C, 20°C to 130°C, 20°C to 120°C, 20°C to 110°C, 20°C to 100°C, 20°C to 90°C, 20°C to 80°C, 20°C to 70°C, 20°C to 60°C, 20°C to 50°C, 20°C to 40°C, 20°C to 30°C, 30°C to 150°C, 40°C to 150°C, 50°C to 150°C, 60°C to 150°C, 70°C to 150°C, 80°C to 150°C, 90°C to 150°C, 100°C to 150°C, 110°C to 150°C, 120°C to 150°C, 130°C to 150°C, or 140°C to 150°C. In some embodiments, contacting is performed at or to a temperature at or above the boiling point of the non-coordinating solvent.

[0025] In some embodiments, the cyclopentadienyl compound comprises a metal alkyl cyclopentadienyl compound. In some embodiments, the metal alkyl cyclopentadienyl compound is a compound or salt of the formula:

[0026] [R 1 R 2 —Cp]M

[0027] in:

[0028] Cp is cyclopentadienyl;

[0029] R 1 and R 2 are each independently hydrogen or alkyl;

[0030] M is Na, Li or K.

[0031] In some embodiments, R 1 With R 2 In some embodiments, R 1 With R 2 different.

[0032] In some embodiments, R 1 is an alkyl group and R 2 In some embodiments, R 1 and R 2 are each independently an alkyl group.

[0033] In some embodiments, the yttrium trihalide compound includes at least one of YCl 3 , YI 3 , YBr 3 , YF 3 , or any combination thereof.

[0034] In some embodiments, the non-coordinating solvent comprises a solvent that does not coordinate with any compound or complex. In some embodiments, the non-coordinating solvent comprises at least one of toluene, benzene, hexane, heptane, xylene, or any combination thereof. In some embodiments, the non-coordinating solvent does not comprise tetrahydrofuran.

[0035] In some embodiments, the yttrium complex comprises a tri(alkylcyclopentadienyl)yttrium(III) complex. In some embodiments, the yttrium complex is a complex of the formula:

[0036]

[0037] in:

[0038] R 1 and R 2 Each is independently hydrogen or alkyl.

[0039] In some embodiments, R 1 With R 2 In some embodiments, R 1 With R 2 different.

[0040] In some embodiments, R 1 is an alkyl group and R 2 In some embodiments, R 1 and R 2 are each independently an alkyl group.

[0041] In some embodiments, the molar ratio of yttrium trichloride to the cyclopentadienyl compound is from 1:3 to 1:9, or any range or sub-range therebetween. For example, in some embodiments, the molar ratio of yttrium trichloride to the cyclopentadienyl compound is from 1:3 to 1:8, 1:3 to 1:7, 1:3 to 1:6, 1:3 to 1:5, 1:3 to 1:4, 1:4 to 1:9, 1:5 to 1:9, 1:6 to 1:9, 1:7 to 1:9, or 1:8 to 1:9.

[0042] In some embodiments, the yttrium complex is not coordinated to tetrahydrofuran.

[0043] In some embodiments, the yield of the yttrium complex is 50% to 75%, or any range or subrange therebetween. In some embodiments, the yield of the yttrium complex is 55% to 75%, 60% to 75%, 65% to 75%, 70% to 75%, 50% to 70%, 50% to 65%, 50% to 60%, or 50% to 55%.

[0044] At step 104 , in some embodiments, method 100 includes removing at least a portion of the non-coordinating solvent to obtain a solid yttrium complex (eg, a yttrium complex in a solid phase).

[0045] In some embodiments, removal includes techniques for separating the non-coordinating solvent from the yttrium complex. For example, in some embodiments, removal is performed using a cannula. In some embodiments, removal includes decanting the non-coordinating solvent to obtain the yttrium complex. In some embodiments, removal includes pipetting the non-coordinating solvent to obtain the yttrium complex. In some embodiments, removal includes pouring out the non-coordinating solvent to obtain the yttrium complex. In some embodiments, removal includes transferring the non-coordinating solvent to another reaction vessel to obtain the yttrium complex. In some embodiments, removal includes evaporating the non-coordinating solvent to obtain the yttrium complex.

[0046] At step 106 , in some embodiments, method 100 includes recrystallizing the yttrium complex.

[0047] In some embodiments, the recrystallization comprises contacting the yttrium complex with a solvent. In some embodiments, the recrystallization comprises dissolving the yttrium complex in a solvent. In some embodiments, the recrystallization comprises solubilizing the yttrium complex in a solvent. In some embodiments, the recrystallization comprises heating the yttrium complex in a solvent and subsequently cooling the yttrium complex and solvent. In some embodiments, the recrystallization comprises combining the yttrium complex and a solvent. In some embodiments, the recrystallization comprises adding the yttrium complex and a solvent. In some embodiments, the recrystallization comprises stirring the yttrium complex and the solvent. In some embodiments, the recrystallization comprises mixing the yttrium complex and the solvent. In some embodiments, the solvent comprises at least one of the non-coordinating solvents disclosed herein.

[0048] In some embodiments, method 100 does not include any sublimation steps. In some embodiments, method 100 does not include any steps involving tetrahydrofuran.

[0049] Some embodiments relate to a composition. In some embodiments, the composition comprises or consists of a yttrium complex. In some embodiments, the yttrium complex is a complex formed according to the methods disclosed herein. In some embodiments, the composition comprises a yttrium complex of the formula:

[0050]

[0051] in:

[0052] R 1 and R 2 Each is independently hydrogen or alkyl.

[0053] In some embodiments, R 1 With R 2 In some embodiments, R 1 With R 2 different.

[0054] In some embodiments, R 1 is an alkyl group and R 2 In some embodiments, R 1 and R 2 are each independently an alkyl group.

[0055] In some embodiments, the yttrium complex is not coordinated to tetrahydrofuran.

[0056] In some embodiments, the yttrium complex has a purity of at least 70%, at least 75%, at least 80%, at least 85%, at least 90%, at least 95%, at least 96%, at least 97%, or at least 98%. In some embodiments, the yttrium complex has a purity of 70% to 99%, 75% to 99%, 80% to 99%, 85% to 99%, 90% to 99%, 95% to 99%, 96% to 99%, 97% to 99%, or 98% to 99%. In some embodiments, the yttrium complex has a purity of 99% or greater. In some embodiments, the purity of the yttrium complex is determined by 1 H NMR determination.

[0057] In some embodiments, the yttrium complex is a solid. In some embodiments, the composition does not include a bis(alkylcyclopentadienyl)yttrium(III) complex. In some embodiments, the composition does not include at least one of the following impurities: (RCp)3Y·THF, (RCp)2YCl, (RCp)YCl2, or any combination thereof; wherein R is R 1 or R 2 ; and Cp is cyclopentadienyl.

[0058] Comparative Example 1

[0059] Synthesis of Tris(Methylcyclopentadienyl)Yttrium(III) Complex

[0060] As a comparative example, tris(methylcyclopentadienyl)yttrium(III) complex was synthesized from sodium methylcyclopentadienyl (MeCpNa) and yttrium(III) chloride in tetrahydrofuran (THF). The synthesis involved charging MeCpNa and YCl3 (2 g) into a 250 mL Schlenk flask at room temperature under nitrogen, followed by the addition of THF with stirring. The molar ratio of YCl3 to MeCpNa was 1:4. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce the following: 1 H-NMR determined the yellow product of (MeCp)3Y to be 56% yield and 90% purity.

[0061] Example 2

[0062] Synthesis of Tris(Methylcyclopentadienyl)Yttrium(III) Complex

[0063]

[0064] Tris(methylcyclopentadienyl)yttrium(III) complex was synthesized from sodium methylcyclopentadienyl (MeCpNa) and yttrium(III) chloride in toluene. The synthesis involved charging MeCpNa and YCl3 (2 g) into a 250 mL Schlenk flask at room temperature under nitrogen, and then adding toluene with stirring. The molar ratio of YCl3 to MeCpNa was 1:3. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce 1 H-NMR determined the yellow product (MeCp)3Y with a yield of 64% and a purity greater than 96%. 1 Recrystallization of (MeCp)3Y in hexane achieved a purity greater than 98% as determined by H-NMR.

[0065] 1 H NMR(C6D6): 5.93ppm(m,6H,Cp-H), 5.84ppm(m,6H,Cp-H), 1.91ppm(s,9H,Cp-CH3).

[0066] 13 C NMR(C6D6):121.74,116.39,111.98,14.73.

[0067] Example 3

[0068] Synthesis of Tris(Methylcyclopentadienyl)Yttrium(III) Complex

[0069] Tris(methylcyclopentadienyl)yttrium(III) complex was synthesized from sodium methylcyclopentadienyl (MeCpNa) and yttrium(III) chloride in toluene. The synthesis involved charging MeCpNa and YCl3 (2 g) into a 250 mL Schlenk flask at room temperature under nitrogen, and then adding toluene with stirring. The molar ratio of YCl3 to MeCpNa was 1:4. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce 1 H-NMR determined the yellow product (MeCp)3Y with a yield of 54% and a purity greater than 95%. 1 Recrystallization of (MeCp)3Y in hexane achieved a purity greater than 98% as determined by H-NMR.

[0070] Example 4

[0071] Synthesis of Tris(Methylcyclopentadienyl)Yttrium(III) Complex

[0072] Tris(methylcyclopentadienyl)yttrium(III) complex was synthesized from sodium methylcyclopentadienyl (MeCpNa) and yttrium(III) chloride in toluene. The synthesis involved charging MeCpNa and YCl3 (5 g) into a 250 mL Schlenk flask at room temperature under nitrogen, and then adding toluene with stirring. The molar ratio of YCl3 to MeCpNa was 1:4. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce 1 H-NMR determined the yellow product (MeCp)3Y with a yield of 65% and a purity greater than 95%. 1 Recrystallization of (MeCp)3Y in hexane achieved a purity greater than 98% as determined by H-NMR.

[0073] Example 5

[0074] Synthesis of Tris(Methylcyclopentadienyl)Yttrium(III) Complex

[0075] Tris(methylcyclopentadienyl)yttrium(III) complex was synthesized from sodium methylcyclopentadienyl (MeCpNa) and yttrium(III) chloride in toluene. The synthesis involved charging MeCpNa and YCl3 (10 g) into a 250 mL Schlenk flask at room temperature under nitrogen, and then adding toluene with stirring. The molar ratio of YCl3 to MeCpNa was 1:4. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce 1 H-NMR determined the yellow product (MeCp)3Y to be 61% yield and greater than 96% purity. 1 Recrystallization of (MeCp)3Y in hexane achieved a purity greater than 98% as determined by H-NMR.

[0076] Table 1: Synthesis results of (MeCp)3Y of Examples 1 to 5

[0077]

[0078] Example 6

[0079] Synthesis of Tris(Isopropyl-Methyl-Cyclopentadienyl)Yttrium(III) Complex

[0080] Tris(dialkylcyclopentadienyl)yttrium(III) complex was synthesized from sodium 3-isopropyl-1-methyl-1,3-cyclopentadienyl (iPrMeCpNa) and yttrium(III) chloride in toluene. The synthesis involved charging iPrMeCpNa and YCl3 (10 g) into a 250 mL Schlenk flask at room temperature under nitrogen, followed by the addition of toluene with stirring. The molar ratio of YCl3 to iPrMeCpNa was 1:4. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce 1 H-NMR determined the yellow product of (iPrMeCp)3Y with a yield of 50% and a purity greater than 90%. 1 Recrystallization of (iPrMeCp)3Y in hexane achieved a purity greater than 98% as determined by H-NMR.

[0081] Example 7

[0082] Synthesis of Tri(butylcyclopentadienyl)yttrium(III) Complex

[0083] Tri(butylcyclopentadienyl)yttrium(III) complex was synthesized from sodium sec-butylcyclopentadienyl (sec-butyl-CpNa) and yttrium(III) chloride in toluene. The synthesis involved charging sec-butyl-CpNa and YCl3 (10 g) into a 250 mL Schlenk flask at room temperature under nitrogen, followed by the addition of toluene with stirring. The molar ratio of YCl3 to sec-butyl-CpNa was 1:4. The resulting mixture was heated to 55°C for 6 hours and then allowed to settle overnight. The mother liquor was transferred to another Schlenk flask via cannula. All volatiles were removed under vacuum to produce 1 H-NMR determined the yellow product of (sec-butyl-Cp)3Y with a yield of 50% and a purity greater than 90%. 1 Recrystallization of (sec-butyl-Cp)3Y in hexane achieved a purity greater than 98% as determined by H-NMR.

[0084] aspect

[0085] Various aspects are described below. It should be understood that any one or more features listed in the following aspects may be combined with any one or more other aspects.

[0086] Aspect 1. A composition comprising:

[0087] The complex of the formula:

[0088]

[0089] in:

[0090] R 1 and R 2 are each independently hydrogen or alkyl;

[0091] wherein the complex has 1 At least 70% purity as determined by H NMR;

[0092] The complex is a non-sublimed product.

[0093] Aspect 2. The composition according to aspect 1, wherein R 1 is an alkyl group and R 2 For hydrogen.

[0094] Aspect 3. The composition according to any one of aspects 1 to 2, wherein the alkyl group is a linear alkyl group.

[0095] Aspect 4. The composition according to any one of aspects 1 to 3, wherein the alkyl group is a branched alkyl group.

[0096] Aspect 5. The composition according to any one of aspects 1 to 4, wherein R 1 and R 2are each independently an alkyl group.

[0097] Aspect 6. The composition according to any one of aspects 1 to 5, wherein the alkyl group is a C1 alkyl group, a C3 alkyl group, or a C4 alkyl group.

[0098] Aspect 7. The composition according to any one of aspects 1 to 6, wherein the alkyl group is methyl.

[0099] Aspect 8. The composition according to any one of aspects 1 to 7, wherein the alkyl group is n-propyl or isopropyl.

[0100] Aspect 9. The composition according to any one of aspects 1 to 8, wherein the alkyl group is n-butyl, sec-butyl, tert-butyl or isobutyl.

[0101] Aspect 10. The composition according to any one of aspects 1 to 9, wherein the alkyl group is methyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl or isobutyl.

[0102] Aspect 11. The composition of any one of aspects 1 to 10, wherein the complex has a purity of at least 95%.

[0103] Aspect 12. The composition according to any one of aspects 1 to 11, wherein the complex has a purity of 95% to 99%.

[0104] Aspect 13. The composition of any one of aspects 1 to 12, wherein the complex is not coordinated to tetrahydrofuran.

[0105] Aspect 14. A method for forming a compound, the method comprising:

[0106] A metal alkylcyclopentadienyl compound is contacted with a yttrium trihalide compound in a non-coordinating solvent to obtain a tris(alkylcyclopentadienyl)yttrium complex.

[0107] Aspect 15. The method according to aspect 14, wherein the metal alkylcyclopentadienyl compound comprises a compound of the formula:

[0108] [R 1 R 2 -Cp]3M

[0109] in:

[0110] Cp is cyclopentadienyl;

[0111] R 1 and R 2 are each independently hydrogen or alkyl;

[0112] M is Na, Li or K.

[0113] Aspect 16. The method according to any one of aspects 14 to 15, wherein R 1 is an alkyl group and R 2 For hydrogen.

[0114] Aspect 17. The method according to any one of aspects 14 to 15, wherein the alkyl group is a linear alkyl group.

[0115] Aspect 18. The method according to any one of aspects 14 to 15, wherein the alkyl group is a branched alkyl group.

[0116] Aspect 19. The method according to any one of aspects 14 to 15, wherein R 1 and R 2 are each independently an alkyl group.

[0117] Aspect 20. The method according to any one of aspects 14 to 15, wherein the alkyl group is a C1 alkyl group, a C3 alkyl group, or a C4 alkyl group.

[0118] Aspect 21. The method according to any one of aspects 14 to 15, wherein the alkyl group is methyl.

[0119] Aspect 22. The method according to any one of aspects 14 to 15, wherein the alkyl group is n-propyl or isopropyl.

[0120] Aspect 23. The method according to any one of aspects 14 to 15, wherein the alkyl group is n-butyl, sec-butyl, tert-butyl or isobutyl.

[0121] Aspect 24. The method according to any one of aspects 14 to 15, wherein the alkyl group is methyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl or isobutyl.

[0122] Aspect 25. The method according to any one of aspects 14 to 24, wherein the yttrium trihalide compound comprises at least one of YCl 3 , YI 3 , YBr 3 , YF 3 , or any combination thereof.

[0123] Aspect 26. The method of any one of aspects 14 to 25, wherein the non-coordinating solvent comprises at least one of toluene, benzene, hexane, heptane, xylene, or any combination thereof.

[0124] Aspect 27. The method according to any one of aspects 14 to 26, wherein the contacting is performed at a temperature of 20°C to 150°C.

[0125] Aspect 28. The method of any one of aspects 14 to 27, wherein the non-coordinating solvent does not comprise tetrahydrofuran.

[0126] Aspect 29. The method according to any one of aspects 14 to 28, wherein the method does not include any sublimation step.

[0127] Aspect 30. The method according to any one of aspects 14 to 29, wherein the tri(alkylcyclopentadienyl)yttrium complex is a complex of the formula:

[0128]

[0129] in:

[0130] R 1 and R 2 Each is independently hydrogen or alkyl.

[0131] Aspect 31. The method according to any one of aspects 14 to 30, wherein R 1 is an alkyl group and R 2 For hydrogen.

[0132] Aspect 32. The method according to any one of aspects 14 to 30, wherein the alkyl group is a linear alkyl group.

[0133] Aspect 33. The method according to any one of aspects 14 to 30, wherein the alkyl group is a branched alkyl group.

[0134] Aspect 34. The method according to any one of aspects 14 to 30, wherein R 1 and R 2 are each independently an alkyl group.

[0135] Aspect 35. The method according to any one of aspects 14 to 30, wherein the alkyl group is a C1 alkyl group, a C3 alkyl group, or a C4 alkyl group.

[0136] Aspect 36. The method according to any one of aspects 14 to 30, wherein the alkyl group is methyl.

[0137] Aspect 37. The method according to any one of aspects 14 to 30, wherein the alkyl group is n-propyl or isopropyl.

[0138] Aspect 38. The method according to any one of aspects 14 to 30, wherein the alkyl group is n-butyl, sec-butyl, tert-butyl or isobutyl.

[0139] Aspect 39. The method according to any one of aspects 14 to 30, wherein the alkyl group is methyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl or isobutyl.

[0140] Aspect 40. The method according to any one of aspects 14 to 30, wherein the complex has a purity of at least 95%.

[0141] Aspect 41. The method according to any one of aspects 14 to 30, wherein the complex has a purity of 95% to 99%.

[0142] Aspect 42. The method according to any one of aspects 14 to 41, further comprising:

[0143] At least a portion of the non-coordinating solvent is removed to obtain the tris(alkylcyclopentadienyl)yttrium complex in a solid phase.

[0144] It is understood that changes in details, particularly in the construction materials used and the shape, size and arrangement of parts can be made without departing from the scope of the present disclosure.This specification and described embodiments are examples, and the true scope and spirit of the disclosure is indicated by the following claims.

Claims

1. A composition comprising: The complex of the formula: in: R 1 and R 2 are each independently hydrogen or alkyl; wherein the complex has 1 At least 70% purity as determined by H NMR; The complex is a non-sublimed product.

2. The composition according to claim 1, wherein R 1 is an alkyl group and R 2 For hydrogen.

3. The composition according to claim 1, wherein R 1 and R 2 are each independently an alkyl group.

4. The composition according to claim 1, wherein the alkyl group is a C1 alkyl group, a C3 alkyl group or a C4 alkyl group. The composition according to claim 1 , wherein the alkyl group is a methyl group. The composition according to claim 1 , wherein the alkyl group is n-propyl or isopropyl.

7. The composition of claim 1, wherein the alkyl group is n-butyl, sec-butyl, tert-butyl, or isobutyl.

8. The composition of claim 1, wherein the complex has a purity of 95% to 99%.

9. The composition of claim 1, wherein the complex is not coordinated to tetrahydrofuran.

10. A method for forming a compound, the method comprising: A metal alkylcyclopentadienyl compound is contacted with a yttrium trihalide compound in a non-coordinating solvent to obtain a tris(alkylcyclopentadienyl)yttrium complex.

11. The method of claim 10, wherein the metal alkylcyclopentadienyl compound comprises a compound of the formula: [R 1 R 2 -Cp]3M in: Cp is cyclopentadienyl; R 1 and R 2 are each independently hydrogen or alkyl; M is Na, Li or K.

12. The method according to claim 11, wherein R 1 is an alkyl group and R 2 For hydrogen.

13. The method according to claim 11, wherein R 1 and R 2 are each independently an alkyl group. The method according to claim 11 , wherein the alkyl group is a C1 alkyl group, a C3 alkyl group or a C4 alkyl group.

15. The method of claim 11, wherein the alkyl group is methyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, or isobutyl.

16. The method of claim 11, wherein the yttrium trihalide compound comprises at least one of YCl3, YI3, YBr3, YF3, or any combination thereof.

17. The method of claim 11, wherein the non-coordinating solvent comprises at least one of toluene, benzene, hexane, heptane, xylene, or any combination thereof.

18. The method of claim 11, wherein the contacting is performed at a temperature of 20°C to 150°C.

19. The method of claim 11, wherein the tris(alkylcyclopentadienyl)yttrium complex is a complex of the formula: in: R 1 and R 2 Each is independently hydrogen or alkyl.

20. The method of claim 11, further comprising: At least a portion of the non-coordinating solvent is removed to obtain the tris(alkylcyclopentadienyl)yttrium complex in a solid phase.

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