Direct synthesis of organotin alkoxides

Abstract

Synthetic approaches have been described for forming organotin trialkoxide compounds by direct alkylation of tin alkoxides. The first method involves the reaction of an alkali metal tin trialkoxide with an organohalide compound (RX n , where X is a halide atom and n≧1) to form a compound of the formula R[Sn(OR′)3] n The second method involves the formation of a monoorganotin trialkoxide of the formula RSn(OR')3 by reacting a di-tin tetraalkoxide or an alkali metal tin trialkoxide with a fluorinated organohalide compound (R F X) in a UV-light-promoted reaction with the compound of formula R F The present invention includes a method for forming fluorinated monoorganotrialkoxides represented by Sn(OR')3. The disclosed method provides high monoorgano selectivity. Corresponding organotin trialkoxide compositions are also described. These compositions are useful for patterning by radiation, particularly EUV radiation. The organotin trialkoxide compositions can be formed as radiation-patternable coatings on substrates.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to co-pending U.S. Provisional Patent Application No. 63 / 429,261, entitled "Selective Synthesis of Organotin Alkoxides," filed December 1, 2022, to Jilek et al., which is incorporated herein by reference.

[0002] The present invention describes a versatile synthetic method for forming organotin trialkoxide compounds involving the direct alkylation of tin alkoxides, avoiding hydrolyzable ligand substitution. The synthetic method involves the use of alkali metal tin trialkoxide or di-tin tetraalkoxide starting materials, both of which demonstrate high mono-organo specificity. The present invention also relates to polytin compounds with bridging organoligands that form C-Sn bonds to each of the tin atoms. [Background technology]

[0003] Organometallic compounds provide metal ions for thin film deposition in solution or vapor phase. Organotin compounds provide high EUV absorption and radiation-sensitive tin-ligand bonds that can be used to lithographically pattern thin films. The fabrication of semiconductor devices with increasingly smaller dimensions using EUV irradiation requires new materials with wide processing latitude to achieve the required patterning resolution and low defect densities. Summary of the Invention [Means for solving the problem]

[0004] In one aspect, the present invention relates to a method for synthesizing monoorganotin trialkoxides, which comprises reacting MSn(OR') with RX n React with R[Sn(OR')3] nwhere M is Li, Na, K, Rb, or Cs; X is Cl, Br, or I; and n≧1. R is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond. R′ is an organic group having 1 to 10 carbon atoms. These organic groups may optionally contain heteroatoms and / or unsaturated bonds.

[0005] In another aspect, the present invention relates to a method for synthesizing monoorganotin trialkoxides, which includes reacting Sn(OR') with RX under ultraviolet light to form RS(OR'), where X is Cl, Br, or I. R is an organic group having 1 to 31 carbon atoms and forming a C-Sn bond. R' is an organic group having 1 to 10 carbon atoms. These organic groups may optionally contain heteroatoms and / or unsaturated bonds.

[0006] In yet another aspect, the present invention provides a compound of formula ((R'O)3Sn) n Also related are organometallic compounds represented by —R, where n≧3; R′ is an organic group having 1 to 10 carbon atoms; and R is an organic group having 5 to 31 carbon atoms, which together with each Sn atom form a C—Sn bond.

[0007] In yet another aspect, the present invention relates to a method for forming a fluorinated organometallic compound of the formula (CF)RS(OR'), where R is an organic group having 1 to 31 carbon atoms and forming a C-Sn bond; and R' is an organic group having 1 to 10 carbon atoms. The method includes reacting (CF)RS with Sn(OR') or MS(OR'), where X is Cl, Br, or I, under visible or ultraviolet light.

[0008] In another aspect, the present invention provides a compound of formula (CF3)2R 1 CR 0It also relates to fluorinated organometallic compounds represented by Sn(OR')3, where R 0 is an organic group having 1 to 31 carbon atoms and forming a C-Sn bond; R 1 is a hydrogen atom, a halogen atom, or an organic group having 1 to 10 carbon atoms; and R' is an organic group having 1 to 10 carbon atoms. [Brief explanation of the drawings]

[0009] [Figure 1] 1H NMR spectrum of KSn(OtBu)3 in THF. [Figure 2] 119Sn NMR spectrum of KSn(OtBu)3 in THF. [Figure 3] This is the 119Sn NMR spectrum of MeSn(OtBu)3. [Figure 4] 1H NMR spectrum of iPrSn(OtBu)3. [Figure 5] This is the 119Sn NMR spectrum of iPrSn(OtBu)3. [Figure 6] This is the 119Sn NMR spectrum of nPrSn(OtBu)3. [Figure 7] This is the 119Sn NMR spectrum of nPrSn(OtBu)3. [Figure 8] 1H NMR spectrum of 1-but-3-yltin tris(tert-butyloxide) (MAL). [Figure 9] 119Sn NMR spectrum of 1-but-3-yltin tris(tert-butyloxide) (MAL). [Figure 10] 1H NMR spectrum of 2,2,2-trifluoroethyltin tris(tert-butyloxide) (TFE). [Figure 11] 119Sn NMR spectrum of 2,2,2-trifluoroethyltin tris(tert-butyloxide) (TFE). [Figure 12]19F NMR spectrum of 2,2,2-trifluoroethyltin tris(tert-butyloxide) (TFE). [Figure 13] This is the 1H NMR spectrum of CF3CH2Sn(OtBu)3. [Figure 14] This is the 119Sn NMR spectrum of CF3CH2Sn(OtBu)3. [Figure 15] 119Sn NMR spectra of a solution of KSn(OtBu)3 and CF3CH2I after 1 hour of irradiation with green LED light (A) and after 3 hours of irradiation with green LED light (B). [Figure 16] 19F NMR spectra of a solution of KSn(OtBu)3 and CF3CH2I after 1 hour of irradiation with green LED light (A) and after 3 hours of irradiation with green LED light (B). [Figure 17] 1H NMR spectrum of C4H8Sn2(OtBu)6 in C6D6. [Figure 18] This is the 119Sn NMR spectrum of C4H8Sn2(OtBu)6 in C6D6. [Figure 19] 1H NMR spectrum of (C6H3(CH2Sn(OtBu)3)3 in C6D6. [Figure 20] This is the 119Sn NMR spectrum of (C6H3(CH2Sn(OtBu)3)3 in C6D6. [Figure 21] 1H NMR spectrum of 3,3,3,4,4,4-hexafluoroisobutyltin tris(tert-butyloxide) (HFB). [Figure 22] 119Sn NMR spectrum of 3,3,3,4,4,4-hexafluoroisobutyltin tris(tert-butyloxide) (HFB). [Figure 23] 19F NMR spectrum of 3,3,3,4,4,4-hexafluoroisobutyltin tris(tert-butyloxide) (HFB). DETAILED DESCRIPTION OF THE INVENTION

[0010] A novel synthetic route to organotin trialkoxide compositions based on oxidative stannylation starting from Sn(II) alkoxides has been discovered, which provides high selectivity and efficiency. In some embodiments, the novel synthetic method is based on reacting a tin(II) alkoxide with a potassium alkoxide to form an intermediate bimetallic alkali metal tin trialkoxide composition, e.g., potassium tin(II) trialkoxide, and then reacting the intermediate bimetallic composition with an alkyl halide to form a monoalkyltin trialkoxide composition. In other embodiments, an effective synthetic method is based on reacting a di-tin tetraalkoxide with an organohalide under UV light to directly synthesize organotin trialkoxides, with the tin halide alkoxide by-product being easily separated. The methods described herein can provide high selectivity and yield and allow for the preparation of monoalkyltin trialkoxide compositions without the need to perform ligand exchange or conversion reactions, such as the conversion of monoalkyltin triamides to monoalkyltin trialkoxides. The methods described herein can be useful for preparing monoalkyltin trialkoxides having primary or secondary Sn-C bonds. In some embodiments, the organic group, e.g., an aromatic group, can be a bridging organic ligand having direct C-Sn bonds to multiple Sn atoms, e.g., two, three, or more tin atoms. Furthermore, the reactions described herein can be used to prepare organotin compounds having fluorinated organic groups, e.g., R F These compounds may be useful for preparing SnL3 compounds, where R F (wherein R is an alkyl group substituted with one or more fluorine atoms, particularly with multiple trifluoromethyl (F3C-) groups.) The organotin trialkoxides so obtained can be desirable precursors for radiation-based patterning compositions, particularly for efficient EUV patterning.

[0011] As used herein, and generally consistent with usage in the art, the terms "organotin," "hydrocarbyltin," and "alkyltin" can be used interchangeably, and similarly, "monoalkyl" can be used interchangeably with "monoorgano" or "monohydrocarbyl." An "alkyl" ligand is one in which tin is bonded to carbon (generally sp 3 or sp 2 This suggests that the "alkyl" group is bonded to the tin (via a hybrid orbital) to form a bond that generally cannot be hydrolyzed by contact with water. The "alkyl" group can also have internal unsaturated bonds and heteroatoms (i.e., atoms other than carbon and hydrogen) that are not bonded to the tin. Similarly, when we refer to an alkoxide group, we are referring to a group that is bonded to an oxygen-bearing organic substituent at the oxygen atom. The novel synthetic method described herein provides monoalkyltin trialkoxides in high yields, with low (non-tin) metal and polyalkyl (i.e., polyhydrocarbyl) contaminants, and is easily purified. The synthetic approach is amenable to efficient scale-up for commercial production, and the reaction is straightforward and can be carried out in a single-pot synthesis.

[0012] Organotin compounds, particularly monoalkyltin trialkoxide and triamide compounds, have found use as precursors to high-performance photoresists for EUV lithography. The use of alkyltin compounds in high-performance radiation-based patterning compositions is described, for example, in U.S. Pat. No. 9,310,684 (Meyers et al., titled "Organometallic Solution Based High Resolution Patterning Compositions"), which is incorporated herein by reference. Improvements to these organometallic compositions for patterning are described in U.S. Pat. No. 10,642,153 (Meyers et al., titled "Organometallic Solution Based High Resolution Patterning Compositions and Corresponding Methods") and U.S. Pat. No. 10,228,618 (hereinafter referred to as the '618 patent) (Meyers et al., titled "Organotin Oxide Hydroxide Patterning Compositions, Precursors, and Patterning"), both of which are incorporated herein by reference.

[0013] The compositions synthesized herein can be effective precursors to form alkyltin oxo-hydroxo compositions, which are advantageous for high-resolution patterning, e.g., extreme ultraviolet (EUV), ultraviolet (UV), and electron beam lithography. The alkyltin precursor compositions can be hydrolyzed under appropriate conditions using water or other suitable reactants to form monoorganotin oxo-hydroxo patterning compositions (which, when fully hydrolyzed, have the formula RSnO (1.5-(x / 2)) (OH) x(Here, it can be represented by 0 < x ≦ 3) and a group capable of forming it is included. In situ, for example, during the deposit and / or following the formation of the first coating, it may be convenient to carry out hydrolysis to form an oxo-hydroxo composition. For example, organotin triamides and organotin triacetylides, as described in the '618 patent cited above, can be used under hydrolytic conditions to form a radiation-sensitive coating for pattern formation, but it is desirable to use organotin trialkoxides as part of the film-forming composition. The direct synthesis of organotin trialkoxides is described herein.

[0014] Monoorganotin compositions can generally be represented by the formula RSnL3, where R is an alkyl group and L is a hydrolyzable ligand. In a process for forming a radiation-patternable coating, generally, L is hydrolyzed before or during the deposit (e.g., in situ) to produce a coating containing a polymeric organotin oxo-hydroxo composition on a substrate, where the Sn-R bond remains substantially intact. As a result, it is possible to achieve a radiation-patternable coating having radiation-sensitive Sn-R (Sn-C) bonds.

[0015] The novel synthesis method described herein is advantageous for efficiently forming R-Sn bonds using a wide variety of R groups having heteroatoms and can provide improvements compared to R groups having unsubstituted alkyl groups in terms of thermal sensitivity and / or photosensitivity. Without wishing to be bound by theory, generally, the presence of the R ligand hinders the formation of extensive networks and the aggregation of organotin films, and upon irradiation of its starting material, cleavage of the Sn-C bond occurs, thereby enabling subsequent processing for condensing and / or densifying the film.

[0016] During radiation patterning, the hydrolyzable ligands are generally substantially removed from the precursor composition to form the final patterning composition. Generally, organometallic radiation-sensitive resists are prepared using organotin compositions, such as those having a formula of approximately R z SnO (2-z / 2-x / 2) (OH) xDeveloped based on an alkyltin oxide hydroxide represented by (where 0 < x < 3, 0 < z ≤ 2, x + z ≤ 4, and R is a hydrocarbyl or an organic group forming a carbon bond with a tin atom). Among these compositions, a particularly effective form is a mono-organotin oxide hydroxide where z = 1 in the above formula, and its mono-organotin composition is the center in this specification. Specifically, R may optionally be a residue containing 1 to 31 carbon atoms, substituted with one or more carbon atoms substituted with a group containing one or more heteroatom functional groups such as O, N, Si, Ge, Sn, Te, and / or halogen atoms, or an alkyl, or a cycloalkyl further functionalized with a phenyl or cyano group. In some embodiments, R may contain 10 or fewer carbon atoms, for example, methyl, ethyl, propyl, isopropyl, butyl, t-butyl, isobutyl, or t-amyl. The R group may be a linear, branched (i.e., secondary or tertiary at the metal-bonded carbon atom), or cyclic hydrocarbyl group. Each R group generally has 1 to 31 carbon atoms, specifically 3 to 31 carbon atoms for a group containing a secondary-bonded carbon atom, and 4 to 31 carbon atoms for a group having a tertiary-bonded carbon atom, optionally with an unsaturated or aromatic carbon bond. Specifically, in some pattern-forming compositions, a branched alkyl ligand may be desirable. The formation of an oxo-hydroxo coating involves depositing a tin composition having a hydrolyzable bond, such as RSnL3 (where L is a hydrolyzable ligand, such as an alkoxide, dialkylamine, acetylide, or other suitable hydrolyzable ligand). The hydrolyzable ligand can be hydrolyzed to form an oxo-hydroxo network during the deposition of the coating and / or within the coating after deposition, i.e., when hydrolysis is completed after deposition.Applicants have developed methods for efficiently and effectively forming a wide range of pattern-forming compositions having a variety of R groups with C-Sn bonds, optionally containing a variety of heteroatoms, as further described in U.S. Patent Application Publication No. 2022 / 00064192 (Edison et al., entitled "Methods to Produce Organotin Compositions With Convenient Ligand Providing Reactants"), which is incorporated herein by reference.

[0017] The stability of Sn-C bonds generally likely depends on the substitution of the alpha carbon (C bonded to Sn), and generally increases with decreasing alpha carbon substitution. For example, Sn-R bonds with primary alpha carbons are generally more stable than secondary alpha carbons, which in turn are more stable than tertiary alpha carbons. Furthermore, some unsaturated alpha carbons, such as alkynyl C bonds bonded to Sn (e.g., Sn-C≡C), may be hydrolyzed during processing and therefore may be unsuitable in terms of their radiation sensitivity. Sn-C bond stability correlates with dose sensitivity and / or thermal stability; therefore, less stable Sn-C bonds require lower dissociation energy and are therefore associated with lower doses required for pattern formation. In addition, the thermal stability of Sn-C bonds may similarly depend on the substitution of the alpha carbon, and increasing the degree of alpha carbon substitution may result in a generally undesirable trade-off between decreased thermal stability and increased dose sensitivity. Therefore, it is desirable for new organotin compositions to have both high thermal stability and high dose sensitivity.

[0018] Processing of organotin precursor compositions to obtain organotin oxo-hydroxo coatings generally involves hydrolyzing RSnL3 compositions to obtain the related organotin oxo-hydroxo compositions. Hydrolysis can be carried out prior to the deposition process to obtain soluble organotin oxo-hydroxo species (i.e., clusters, oligomeric species, etc.). These soluble organotin oxo-hydroxo species can then be dissolved and / or dispersed in a suitable solvent to form an organotin photoresist solution, which can then be used to form radiation-patternable organotin oxo-hydroxo coatings. Alternatively, the organotin precursor compositions can be directly dissolved in a suitable solvent to form a photoresist solution, which can then be used to form radiation-patternable organotin oxo-hydroxo coatings. It is also possible to hydrolyze these organotin compositions in situ using water (which may be ambient atmospheric water vapor) during the substrate coating process, for example, during solution deposition or vapor deposition. Various processing options are further described in the '684 and '618 patents referenced above.

[0019] In the case of organotin photoresist precursor compositions, where the organotin compound is dissolved in a solvent for spin-coating, organotin trialkoxides (RSnL3, L = OR') are preferred over other RSnL3 compositions (e.g., organotin triamides, L = NR'2). Some advantages of organotin trialkoxide compositions include the production of relatively harmless, more benign side reaction products, such as alcohols, compared to the production of gaseous reaction products (e.g., amines) that can cause contamination and environmental health and safety (EHS) issues, including on the wafer track and / or in the wafer fab. Furthermore, organotin trialkoxides have significant vapor pressures and low melting points, making them attractive compounds for use in vapor deposition processes to prepare radiation-patternable coatings.

[0020] The synthesis of organotin trialkoxide compounds has been described, for example, in previous patent applications filed by the applicant. However, those reactions resulting in monoalkyltin trialkoxides as the reaction product generally involve the conversion of a non-alkoxide alkyltin compound to an alkyltin alkoxide, rather than direct synthesis. In other words, organotin trialkoxides have generally been synthesized via ligand substitution reactions. For example, organotin trialkoxides can be prepared from the corresponding organotin trichlorides by reaction with alkali metal alkoxides, such as KOR', NaOR', etc., as follows: RSnCl3+3MOR'→RSn(OR')3+3MCl (1)

[0021] Using this synthetic scheme, the potential product space for organotin trialkoxides therefore has practical limitations based on the accessibility and purity of the corresponding organotin trichlorides. Organotin trichlorides are typically synthesized using the well-known Kocheskov reaction, in which tetraalkyltin R4Sn serves as the starting material for the synthesis of other organotin halides produced by redistribution reaction with SnCl4. This reaction is known to be nonselective and highly sensitive to stoichiometry, and typically results in the formation of unwanted R4Sn. n SnCl 4-n This results in some distribution of reaction products. For example, even if a mixture of SnCl and RSn is reacted in a 3:1 ratio to synthesize RSnCl, targeting RSnCl as the primary reaction product, the reaction still produces significant amounts of RSnCl and RSnCl as side reaction products. For semiconductor applications requiring high purity compounds for low defect processing and commercial viability, one or more purification steps may be required to further purify and / or isolate the RSnCl compound before its conversion to trialkoxide, which itself can be labor-intensive. The synthetic methods described herein alleviate the need for high purity organotin trichloride starting materials in the synthesis of organotin trialkoxides.

[0022] Another method for preparing organotin trialkoxides involves the conversion of organotin triamides to organotin trialkoxides according to the following reaction: RSn(NR2”)3+3HOR'→RSn(OR')3+3HNR”2(2)

[0023] Although this reaction is relatively straightforward, the application of this method may be limited by several factors, such as its exothermic nature, its potential for decomposition of the reactants and / or reaction products, and its high cost (because the corresponding organotin triamide must first be synthesized). While applicants have previously published synthetic methods for preparing a wide variety of organotin triamides, there remains a desire to access methods for the direct synthesis of organotin trialkoxides without the need to first obtain an organotin starting material with the desired R ligand identity. The direct synthesis of organotin trialkoxides, RSn(OR'), is desirable and is described herein.

[0024] Direct synthesis of organotin alkoxides: Two related synthetic approaches for the direct synthesis of organotin trialkoxides are described. As shown in the examples, both methods involve the reaction of an organohalide, such as an alkyl halide (RX), with a tin alkoxide compound to form the Sn-R bond. The tin alkoxide can be a di-tin tetraalkoxide (Sn(OR')4) or an alkali metal tin alkoxide, such as MSn(OR')3. In the first approach, the di-tin tetraalkoxide is reacted with the organohalide to form a monoalkyltin trialkoxide, RSn(OR')3, typically in the presence of UV or monochromatic visible light. In the second approach, the alkali metal tin trialkoxide is reacted with the organohalide to form the corresponding organotin trialkoxide, which produces less tin contamination.

[0025] These di-tin tetraalkoxides (Sn(OR')) and alkali metal tin alkoxides (MSn(OR')) can be prepared using methods known in the literature, for example, as described in the following article by Veith et al. (hereinafter referred to as the Veith article): "Alkoxistannate, II Tri(rerr-butoxi)alkalistannates(II): Synthesis and Structures," Z. Naturforsch., 41b, 1071-1080 (1986), which is incorporated herein by reference. The Veith article does not suggest any specific reaction using Sn(OR') or MSn(OtBu) as an additional reactant to form alkyltin trialkoxides, such as RSn(OtBu). The Veith article does disclose the synthesis of MSn(OtBu) using Sn(OtBu). As shown in the examples herein, MSn(OtBu) is synthesized from SnCl and M(OtBu) in a two-step reaction. After the first step, the precipitated MCl(KCl) is removed, but no further purification is necessary.

[0026] As described herein and in the Examples below, monoalkyltin trialkoxides can be synthesized by the following overall reaction: MSn(OR')3+RX→RSn(OR')3(3) where M is typically an alkali metal, such as Li, K, Na, Cs, or Rb. R' is typically an organic group having 10 or fewer carbon atoms, and OR' can be selected based on the properties desired in the reaction product, monoalkyltin trialkoxide, RSn(OR')3, such as stability, melting point, solubility, ease of purification, etc. In some embodiments, M is K. In some embodiments, OR' is tert-butoxide (OtBu). In some embodiments, OR' is tert-amyloxide (OtAm). The R X compound is selected to provide the desired organoligand, R, for the mono-organotin reaction product. The wide availability of R X compounds as reactants, as well as the broad reactivity of these compounds in the corresponding reactions, offers the possibility of incorporating a wide variety of alkyl ligands into the reaction product, monoalkyltin reaction product. X can typically be a halide selected from I, Br, or Cl.

[0027] The reaction of equation (3) can be generalized for the synthesis of poly-tin reaction products with bridging organoligands. nMSn(OR')3+RX n →R(Sn(OR')3) n (4) where n≧1, e.g., 1, 2, 3, 4, or greater, and M is typically an alkali metal, as listed above. Generally, there is no definite limit to the number of tin atoms that can be bridged in this manner, provided reasonable polyhalide reactants are available. In some embodiments, n can be from 2 to about 12. R, X, and R′ are as specified in the preceding paragraphs. In mono-tin or poly-tin embodiments, multiple different R′ groups can be used, if desired.

[0028] In the reactions described herein, primary and secondary R groups (i.e., R groups with C atoms 1° or 2° apart that form a C-Sn bond) can be particularly effective in forming the desired RSn(OR')3 compositions via the synthetic routes described herein. Generally, the R ligands are organoligands having 1 to 31 carbon atoms, optionally substituted with one or more heteroatom functional groups containing one or more O, N, Si, and / or halogen atoms, or alkyl or cycloalkyl groups further functionalized with phenyl or cyano groups with optional unsaturated carbon-carbon or heteroatom bonds. Specifically, olefinic R ligands with unsaturated carbon bonds, such as those shown in the examples herein, can also be prepared. Additionally, polytin compounds with two, three, or more Sn atoms bridged by shared R groups can also be prepared by using polyhalide reactants via the novel synthetic methods described herein. In some embodiments, it may be desirable to have a catalyst present during the reaction to form the monoalkyltin trialkoxide, as further described below.

[0029] In some embodiments, the R ligands may include heteroatom functional groups including O, N, Si, and / or halogen atoms. In some embodiments, the R ligands are fluorinated. Fluorine atoms are desirable to replace H atoms in the R ligands due to their high EUV absorption. In addition, the presence of F atoms in the R ligands can increase the hydrophobicity of the ligands, thereby improving the developer contrast between irradiated and non-irradiated areas of the film.

[0030] In some embodiments, the fluorinated R ligand can contain 2 to 10 carbon atoms and two or more -CF groups, such as in the hexafluorobutyl (HFB) compounds described in the Examples herein. In some embodiments, the R ligand can contain a tertiary carbon bearing a C-F bond, such as -CFR, where R is a hydrocarbyl group having 1 to 10 carbon atoms, such as in the HFP compounds described in the Examples herein.

[0031] In some embodiments, the R ligands may include bridged hydrocarbyl groups shared between two, three, or more Sn atoms. The bridged R ligands generally include linear, branched, cyclic, and / or aromatic hydrocarbyl groups having from 1 to 31 carbon atoms.

[0032] It has been discovered that the alkali tin trialkoxide intermediate, MSn(OR'), a bimetallic alkoxide of Sn(II), is a useful reactant for forming organotin trialkoxides, which can be prepared according to the following reaction: SnCl2+3MOR'→MSn(OR')3+2MCl (4)

[0033] The alkali metal M can generally be selected from Li, Na, K, Cs, or Rb. In some embodiments, M is K. In some embodiments, M is Li or Na. The MSn(OR')3 compounds can be isolated, purified, and used as solid reactants in syntheses, the preparation of which is included in the Examples herein.

[0034] When reacted with an organohalide under moderate temperatures and conditions, an oxidative addition reaction occurs, forming a carbon-tin bond and rapidly forming potassium halide and RSn(OR')3. As shown in the following example, the reaction can be carried out in two steps, first adding two equivalents of MOR' to precipitate MCl, which is then removed. Additional amounts of MOR' can be added, although somewhat less than equivalent amounts may be added to avoid losses during filtration to remove the precipitated MCl. Generally, the precipitated alkali halide, e.g., potassium halide salt, can alternatively be filtered off, and / or the RSn(OR')3 reaction product can be purified and collected, e.g., by distillation.

[0035] In the case of some R groups, such as fluorinated alkyl groups, the corresponding R F Sn(OR') compositions can be synthesized directly from Sn(OR) ([Sn(OR')]) without the use of alkali tin alkoxide compositions, i.e., in the presence of UV or visible light, according to the following reaction: [Sn(OR')2]2+R F X → R F Sn(OR')3+[1 / 2]Sn2X2(OR')2(5)

[0036] The di-tin by-product (SnX(OR')) typically forms as a solid precipitate, which can be separated by filtration or other suitable method. Although described as a reaction for fluorinated organoligands, the reaction can be more generally applicable, if desired.

[0037] In the examples herein, fluorinated alkyltin trialkoxides (where R FThe synthesis of a fluorinated alkyl group (where R' = trifluoroethyl (TFE, CF3CH2-), R' = tert-butyl, and X = halide (Cl, Br, I)) has been described. Without wishing to be bound by theory, it is believed that this reaction with a fluorinated alkyl group involves a radical mechanism that can be accelerated by irradiation with appropriate UV or visible light. In particular, the reaction can be carried out under irradiation with UV or visible light in the absence of a bimetallic tin(II) alkoxide. The reactions can also be carried out using alkali metal tin trialkoxides, and the reactions can be further accelerated by irradiation with visible or UV light. For example, an appropriate light source, such as an LED, laser, or incandescent bulb, can be used to provide UV and / or visible light to the reaction vessel. The light source can generally provide light at a wavelength between 200 nm and 700 nm, and is generally of a wavelength selected to allow sufficient transparency to the reaction vessel (i.e., the reaction apparatus) and sufficient absorption by the chemical species in the reaction medium. In some embodiments, the light source may be monochromatic.

[0038] These reactions are typically carried out in anhydrous organic solvents under an oxygen-free or oxygen-depleted atmosphere, e.g., a nitrogen-purged atmosphere. The solvent is selected to ensure that the various components remain in solution. Because of interactions between the solvent and the metal ions, the solvent selection should be based, at least in part, on the reaction rate in the selected solvent, which can be evaluated experimentally. When different solvents are selected, they are typically miscible. Generally, both aprotic polar and nonpolar solvents are useful, including, for example, alkanes (e.g., hexane, pentane), ethers (e.g., dimethyl ether, diethyl ether), tetrahydrofuran (THF), acetone, toluene, acetonitrile, and mixtures thereof. The solvents should typically be selected to be inert to the reactants, intermediates, and reaction products. For example, if multiple solvents are used to introduce individual reactants, the solvents should typically be miscible with each other.

[0039] The reaction of the bimetallic MSn(OR')3 compound with the alkyl halide RX compound can also be carried out in the presence of a halide-containing catalyst. The catalyst typically includes tetraalkyl (quaternary) ammonium salts, tetraalkyl phosphonium salts, or mixtures thereof, such as tetrabutylammonium iodide, tetrabutylammonium bromide, tetrabutylammonium hexafluorophosphate, and / or tetraphenylphosphonium chloride. Since the catalyst is not consumed, the amount of catalyst can be selected as desired to affect the reaction rate. Typically, the amount of catalyst is a fraction of the stoichiometric amount.

[0040] Reactions using MSn(OR')3 as the starting material can generally be carried out in a single pot without any intermediate steps, such as separation, purification, or transfer. After the reaction between the bimetallic alkoxide MSn(OR')3 and the alkyl halide, the desired organotin alkoxide reaction product can be obtained in pure form by filtration and / or distillation. The use of polyhalide organic reactants allows the bridged organic group R(Sn(OR')3) to be easily separated. n where n>1 and where the organic group R has Sn-C bonds up to the number n of Sn atoms, and tritin reaction products are exemplified.

[0041] The reactions described herein are highly selective for the production of mono-organotin trialkoxide compounds, and the organohalides can generally be present as reactants in molar excess relative to the MSn(OR')3 composition. However, to produce poly-tin reaction products with bridged ligands, stoichiometric amounts of polyhalide organic reactants are used. Similarly, in reactions involving Sn2(OR')4 to directly produce organotin trialkoxides, as shown in equation (5) above, the reaction is also highly specific for the mono-organo reaction product. In some embodiments, the organohalide can be present in the following amounts: up to about 2 molar equivalents relative to the MSn(OR')3 (or Sn2(OR')4) compound; in other embodiments, up to about 1.6 molar equivalents relative to the MSn(OR')3 (or Sn2(OR')4) compound; in other embodiments, up to about 1.3 molar equivalents relative to the MSn(OR')3 (or Sn2(OR')4) compound; and in further embodiments, up to about 1.1 molar equivalents relative to the MSn(OR')3 (or Sn2(OR')4) compound. In some embodiments, the organohalide and MSn(OR')3 (or Sn2(OR')4) compound can be present in approximately stoichiometric amounts. Note that for Sn2(OR')4-based reactions, the formation of a removed Sn by-product limits the yield to 50% based on tin, but this is not a limitation for reactions involving MSn(OR')3 reactants. A person of ordinary skill in the art will recognize that additional ranges of relative reactant amounts within the explicit ranges above are contemplated and are within the present disclosure.

[0042] The reaction can generally be carried out at temperatures below about 100°C in some embodiments, below about 80°C in other embodiments, and below 60°C in further embodiments. In some embodiments, the reaction can be carried out at room temperature. In some embodiments, the reaction can be carried out under UV irradiation. In embodiments where UV irradiation is carried out during the reaction, the reaction can be carried out with or without heating. In some embodiments, the reaction can be cooled and carried out at temperatures from about −80°C to about −60°C, from about −60°C to about −40°C, from about −40°C to about −20°C, and from about −20°C to about 20°C. In some embodiments, the UV irradiation can be carried out at a wavelength of 365 nm. In some embodiments, the UV irradiation can be carried out at a wavelength of 254 nm. In some embodiments, the reaction can be carried out under monochromatic visible light irradiation. The radiation applied during the reaction is generally at a wavelength that is suitably transparent to the reaction apparatus (e.g., reaction vessel, container, etc.), so that significant absorption occurs and the reaction can be accelerated. The reaction is generally stirred for the reaction time. The efficiency of the reaction can be determined by: 1 H NMR and / or 119The reaction mixture can be monitored by analyzing it by Sn NMR to determine when it has reached sufficient completion. In some embodiments, the reaction is carried out for about 5 days, in other embodiments, about 3 days, in other embodiments, about 1 day, and in a further embodiment, about 1 hour. As will be appreciated by those of ordinary skill in the art, additional ranges of times and temperatures within the explicit ranges above are contemplated and are within the present disclosure. Desired reaction times and temperatures generally depend on the identity of the organohalide (RX). The reactivity of organohalides generally follows the order X = I > Br > Cl, with the carbons forming the CX bond = 1° > 2° >> 3°. Suitable reaction times and temperatures can be determined by routine experimentation based on the teachings herein. The reaction is generally carried out under an inert atmosphere, such as a N2 or Ar atmosphere. As will be appreciated by those of ordinary skill in the art, additional ranges of processing conditions within the explicit ranges above are contemplated and are within the present disclosure.

[0043] Once the reaction product is formed, the organotin trialkoxide can be purified. Purification depends on the properties of the reaction product but generally involves separating the desired reaction product from by-products and any potentially present unreacted reactants. Purification can generally be accomplished by methods known to those skilled in the art. Typical purification procedures include filtration, recrystallization, extraction, distillation, sublimation, combinations thereof, and the like. Filtration is typically performed on the crude reaction product mixture using a commercially available filter to remove insoluble contaminants and / or by-products, such as metal halide salts, such as KI, from a solution containing the desired reaction product. Recrystallization methods can be useful for purifying solid compounds by heating a saturated solution and then allowing it to cool and crystallize. Extraction methods can include, for example, liquid-liquid extraction, in which two immiscible solvents with different densities are used to separate the desired compound based on their relative solubilities. Purification can also include removing various volatile compounds, including solvents, from the reaction product mixture by heat drying and / or exposure to vacuum. For reaction products with significant vapor pressure, it is desirable to purify the reaction product via vacuum distillation or, optionally, fractional distillation designed to achieve high purity. See U.S. Patent Application Publication No. 2020 / 0241413 (Clark et al., entitled "Monoalkyl Tin Trialkoxides and / or Monoalkyl Tin Triamides With Low Metal Contamination and / or Particulate Contamination and Corresponding Methods"), which is incorporated herein by reference. In some cases, the reaction product can be purified by sublimation, in which the crude reaction product mixture is heated and / or subjected to reduced pressure, resulting in the collection of a solid reaction product that can be purified by sublimation, which can be collected by deposition onto a target surface, such as a cooled finger.The purification of di-tin compounds by sublimation is illustrated in the Examples herein.

[0044] The organotin trialkoxides RSnL3 (L = OR') described herein can be further elaborated to form the corresponding organotin compounds containing other hydrolyzable ligands, L. In one example, the alkoxide ligand can be replaced with another alkoxide ligand, e.g., one or more OR' ligands can be replaced with OR" ligands by solvolysis and / or alcoholysis. Organotin trialkoxides can also be converted to organotin triamides (RSnL3, L = NR"2), e.g., by reaction of the organotin trialkoxide with LiNR"2 or a similar metal amide. In other examples, the alkoxide ligand can be replaced with an acetylide, amidinate, carboxylate, or the like.

[0045] The hydrolyzable ligands are generally selected based on the desired handling or use, e.g., the desired mode of use in processing the RSnL3 composition into a radiation-patternable film. For example, organotin trialkoxides (RSn(OR')3, L = OR') are desirable for forming resist solutions, while organotin triamides (RSn(NR"2)3) are particularly desirable for use in vapor deposition applications because they generally have high vapor pressures and high reactivity. In either case, i.e., whether L = OR' or L = NR", the hydrolysis and condensation reactions that occur during the deposition process result in the formation of similar organotin oxide hydroxide film compositions, but in which the Sn-C bonds are retained and Sn-O-Sn and Sn-OH bonds are generated by hydrolysis of the Sn-L bonds.

[0046] Coatings, deposits, and related compositions: The organotin precursor compositions described herein can be effectively used in radiation-induced patterning, particularly EUV patterning. The ability to have greater flexibility in R ligand selection allows for further refinement in patterning results and in the design of ligands that are particularly effective for specific applications. Generally, any suitable coating process can be used to transfer the precursor solution to the substrate. Suitable coating approaches include, for example, solution deposition methods such as spin coating, spray coating, dip coating, knife-edge coating, printing methods such as inkjet printing, and screen printing. As described in the above-cited '618 patent, many of the precursors are also suitable for vapor deposition. For some R ligand compositions and / or specific process considerations, vapor deposition methods can be useful for preparing radiation-sensitive coatings.

[0047] After the desired organotin precursor is prepared, the precursor can be dissolved in a suitable solvent, e.g., an organic solvent, such as an alcohol, aromatic or aliphatic hydrocarbon, ester, or a combination thereof, to prepare a precursor solution. Particularly suitable solvents include, for example, aromatic compounds (e.g., xylene, toluene), ethers (anisole, tetrahydrofuran), esters (propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, methanol, isopropyl alcohol, 1-propanol), ketones (e.g., methyl ethyl ketone), mixtures thereof, and the like. Generally, the choice of organic solvent can be influenced by factors such as solubility parameter, volatility, flammability, toxicity, viscosity, and the potential for chemical interaction with other processing materials.

[0048] The organotin precursor can also generally be dissolved in a mixture of solvents to prepare the precursor solution. Some solvent mixtures useful for forming organotin photoresist solutions are described in U.S. Patent Application Publication No. 2023 / 0143592 (Jiang et al., titled "Stability-Enhanced Oranotin Photoresist Compositions"), which is incorporated herein by reference. It is desirable to dissolve the organotin precursor in a solvent mixture containing a primary alcohol. In some embodiments, the solvent includes primary alcohols such as methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol, and the like. In some embodiments, the solvent can include a mixture of two alcohols. In other embodiments, the solvent can include a mixture of an alcohol and an ester. After the components of the solution are dissolved and combined, the properties of the chemical species may change as a result of partial in situ hydrolysis, hydration, and / or condensation.

[0049] The organotin precursor can be dissolved in a solvent to obtain a suitable Sn concentration for forming a coating of suitable thickness for processing. The concentration of the species in the precursor solution can be selected to provide the desired physical properties of the solution. In particular, a low overall concentration can provide desirable solution properties for certain coating approaches, such as spin coating, which can achieve thinner coatings using reasonable coating parameters. Thinner coatings are desirable for achieving ultrafine patterning and reducing material costs. Generally, the concentration can be selected to optimize a selected coating approach. Coating performance is discussed in more detail below. Tin concentrates typically range from about 0.005 M to about 1.4 M, from about 0.02 M to about 1.2 M in a further embodiment, and from about 0.1 M to about 1.0 M in a further embodiment. As those skilled in the art will appreciate, additional ranges of tin concentrations within the ranges explicitly stated above are contemplated and are within the present disclosure.

[0050] In some embodiments, the improved photosensitive precursor composition comprises one or more organotin compositions, such as R n SnL 4-nand its hydrolyzate, where R is selected from various residues detailed herein and explicitly described above. Such blend solutions can be adjusted for optimization based on various performance considerations, such as solution stability, coating uniformity, and patterning performance. In some embodiments, the improved photosensitive composition can include a specific desired component of at least 1 mol % Sn in the blend solution, at least 10 mol % Sn in the blend solution, at least 20 mol % Sn in the blend solution, and at least 50 mol % Sn in the blend solution. Additional ranges of mol % of the improved photosensitive composition within the specified ranges of the blend solution are contemplated and within the scope of the present disclosure. The hydrolyzable ligand L can be hydrolyzed during or after deposition, for example, by hydrolysis with water vapor.

[0051] Generally, due to their high vapor pressure, the organotin compositions described herein can be useful as precursors for forming coatings via vapor deposition. Vapor deposition methods generally include chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and modifications thereof. In a typical vapor deposition process, the organotin compositions can be reacted with small molecule gas-phase reactants, such as HO, O, HO, O, CHOH, HCOOH, CHCOOH, etc., which serve as a source of O and H to produce radiation-sensitive organic tin oxide and oxide hydroxide coatings. Water vapor can be provided from ambient air, in vapor form, or otherwise in the form of a suitable liquid or gaseous composition. A specific apparatus for depositing radiation-patternable organotin coatings is described in the following patent application: PCT Application PCT / US2019 / 031618 (Wu et al., entitled "Methods for Making EUV Patternable Hard Masks," incorporated herein by reference). The production of radiation-sensitive organotin coatings can generally be achieved by reacting a volatile organotin precursor, RSnL3, with small gas-phase molecules. The reaction involves hydrolysis / condensation of the organotin precursor to hydrolyze the hydrolyzable ligands, while leaving the Sn-C bond substantially intact. In some embodiments, two or more different RSnL3 compounds with different R and / or L ligands can be used to form a final film containing a mixture of RSn species.

[0052] Whether deposited by solution deposition or vapor deposition, the hydrolyzable ligands are hydrolyzed to give RSnO. x H 3-2xThis results in the formation of an oxo-hydroxo network represented by the formula: Generally, radiation exposure and patterning is carried out on the hydrolyzed coating.

[0053] In a typical process for radiation-based patterning, e.g., extreme ultraviolet (EUV) lithography, a photoresist material is deposited or coated as a thin film on a substrate, pre-exposure baked, exposed to a pattern of radiation to create a latent image, post-exposure baked, and then a liquid, typically an organic solvent, is used to create a developed pattern of the resist. If desired, fewer steps can be used, or additional steps can be used to remove residue and improve pattern fidelity.

[0054] The thickness of the radiation-patternable coating can depend on the process desired. For use in single-patterning EUV lithography, the coating thickness is generally selected to provide a pattern with few defects and good pattern reproducibility. In some embodiments, a suitable coating thickness is between 0.1 nm and 100 nm, in further embodiments, about 1 nm to 50 nm, and in further embodiments, about 2 nm to 25 nm. As will be appreciated by those skilled in the art, additional ranges of coating thickness are contemplated and are within the present disclosure.

[0055] For radiation-patternable coatings prepared by vapor deposition, the coating thickness can generally be controlled by appropriately selecting the reaction time or number of cycles of the process. The thickness of the radiation-patternable coating can depend on the desired process. For use in single-patterning EUV lithography, the coating thickness is generally selected to provide a pattern with few defects and good pattern reproducibility. In some embodiments, suitable coating thicknesses are between 0.1 nm and 100 nm, in further embodiments, about 1 nm to 50 nm, and in further embodiments, about 2 nm to 25 nm. As will be appreciated by those skilled in the art, additional ranges of coating thickness are contemplated and are within the present disclosure.

[0056] The substrate generally provides a surface onto which a coating material can be deposited, and may be comprised of multiple layers, of which the surface refers to the top layer. The substrate is not particularly limited and may include any suitable material, such as silicon, silica, other inorganic materials, e.g., ceramics, and polymeric materials.

[0057] After deposition to form a radiation-patternable coating, further processing can be employed prior to exposure to radiation. In some embodiments, the coating can be heated between 30°C and 300°C, in further embodiments between 50°C and 200°C, and in further embodiments between 80°C and 150°C. The heating can be carried out in some embodiments for about 10 seconds to about 10 minutes, in further embodiments for about 30 seconds to about 5 minutes, and in further embodiments for about 45 seconds to about 2 minutes. Additional ranges of temperatures and heating times within the explicit ranges above are contemplated and envisioned.

[0058] Patterning of the composition: The radiation can generally be applied directly to the coated substrate through a mask, or the radiation beam can be scanned over the substrate in an adjustable manner. Generally, the radiation can include electromagnetic radiation, electron beam (beta radiation), or other suitable radiation. Generally, the electromagnetic radiation can have a desired wavelength or wavelength range, such as visible light, ultraviolet light, or X-rays. The achievable resolution of a radiation pattern generally depends on the wavelength of the radiation, and generally, higher resolution patterns can be obtained using radiation with shorter wavelengths. Therefore, to obtain particularly high resolution patterns, it is desirable to use ultraviolet light, X-rays, or electron beams.

[0059] According to the international standard ISO 21348 (2007) (incorporated herein by reference), ultraviolet light refers to wavelengths between 100 nm and less than 400 nm. Krypton fluoride lasers can be used as a source of 248 nm ultraviolet light. The ultraviolet range can be further subdivided in several ways in accepted standards, such as extreme ultraviolet (EUV) from 10 nm to less than 121 nm, and far ultraviolet (FUV) from 122 nm to less than 200 nm. The 193 nm line from an argon fluoride laser can be used as a radiation source for FUV. 13.5 nm EUV light has been used for lithography, but this light is generated by Xe or Sn plasma sources excited using high-energy lasers or discharge pulses. Soft x-rays can be defined as from 0.1 nm to less than 10 nm.

[0060] Depending on the design of the coating material, there can be a large contrast in material properties between the irradiated regions (where the coating material is condensed) and the unirradiated regions (where the Sn-C bonds remain substantially unchanged). In embodiments employing a post-irradiation heat treatment, the post-irradiation heat treatment can be carried out at temperatures ranging from about 45°C to about 250°C, in further embodiments from about 50°C to about 190°C, and in a further embodiment from about 60°C to about 175°C. Post-exposure heating can generally be carried out for at least about 0.1 minutes, in further embodiments from about 0.5 minutes to about 30 minutes, and in a further embodiment from about 0.75 minutes to about 10 minutes. Those skilled in the art will recognize that additional ranges of post-irradiation heating temperatures and times within the ranges specified above are contemplated and are within the present disclosure. This high contrast in the material facilitates the formation of high-resolution lines with smooth edges in the pattern, as discussed in the next section.

[0061] For negative-tone imaging, the developer can be an organic solvent, such as the solvent used to form the precursor solution. The choice of developer is generally influenced by the solubility parameters for both irradiated and non-irradiated coating materials, as well as the developer's volatility, flammability, toxicity, viscosity, and potential chemical interactions with other process materials. Specifically, suitable developers include, for example, alcohols (e.g., 4-methyl-2-pentanol, 1-butanol, isopropanol, 1-propanol, methanol), ethyl lactate, ethers (e.g., tetrahydrofuran, dioxane, anisole), esters (propylene glycol monomethyl ether acetate, ethyl acetate, ethyl lactate), ketones (pentanone, hexanone, 2-heptanone, octanone), and mixtures thereof. Suitable developers are further described in U.S. Patent Application Publication No. 2020 / 0326627 (Jiang et al., entitled "Organometallic Photoresist Developer Compositions and Processing Methods"), which is incorporated herein by reference, and such developers generally include solvent blends of ketones, alcohols, ethers, esters, and water, glycol ethers, pyrrolidones, lactones, carboxylic acids, or combinations thereof. Development can be carried out for about 5 seconds to about 30 minutes, in further embodiments from about 8 seconds to about 15 minutes, and in additional embodiments from about 10 seconds to about 10 minutes. A person of ordinary skill in the art will recognize that additional ranges within the explicit ranges above are contemplated and are within the present disclosure.

[0062] When using a weaker developer, such as a diluted organic developer, or a composition in which the coating development rate is slow, a higher temperature development process can be used to increase the processing speed. With a stronger developer, the development process temperature can be lowered to reduce the speed and / or adjust the development kinetics. Generally, the development temperature should be adjusted to an appropriate value that matches the volatility of the solvent. Furthermore, developers that dissolve the coating material near the developer-coating interface can be dispersed ultrasonically during development. The developer can be applied to the patterned coating material using various rational approaches. For example, the developer can be sprayed onto the patterned coating material. Spin coating can also be used. In automated processing, a puddle method can be used, in which the developer is poured onto the coating material in a stationary format. If desired, spin rinsing and / or drying can be used to complete the development process. Suitable rinsing solutions include, for example, ultrapure water, aqueous tetraalkylammonium hydroxide, methyl alcohol, ethyl alcohol, propyl alcohol, and combinations thereof. After the image is developed, the coating material is disposed in a pattern on the substrate.

[0063] In some embodiments, a solvent-free (dry) development process can be carried out using a suitable thermal or plasma development process, such as those described in the following published PCT patent: PCT Application PCT / US / 039615 (Tan et al., entitled "Photoresist Development With Halide Chemistries"), which is incorporated herein by reference. For organotin photoresist coatings, dry development methods can be carried out using halogen-containing plasmas and gases, such as HBr and BCl. In some cases, dry development methods offer advantages over wet development methods, such as reduced pattern collapse, reduced scum, and precise control of the developer composition, i.e., plasma and / or etch gases.

[0064] After the development step is complete, the coating material can be heat-treated to further condense, dehydrate, densify, or remove residual developer from the material. This heat treatment can be particularly desirable in embodiments in which the oxide coating material will be incorporated into an ultimate device, but it is also desirable in some embodiments in which the coating material will be used as a resist and ultimately removed if stabilization of the coating material is desired to facilitate further patterning. In particular, baking of the patterned coating material can be carried out under conditions such that the patterned coating material exhibits a desired level of etch selectivity. In some embodiments, the patterned coating material can be heated to a temperature of from about 100°C to about 600°C, from about 175°C to about 500°C in further embodiments, and from about 200°C to about 400°C in further embodiments. Heating can be carried out for at least about 1 minute, from about 2 minutes to about 1 hour in other embodiments, and from about 2.5 minutes to about 25 minutes in further embodiments. Heating may be carried out in air, vacuum, or an inert gas atmosphere such as Ar or N. A person of ordinary skill in the art will recognize that additional ranges of temperatures and times for heat treatment within the explicit ranges above are contemplated and are within the present disclosure. Similarly, non-heat treatments, such as blanket UV exposure or exposure to an oxidizing plasma such as O, may also be employed in similar processes. [Example]

[0065] Example 1: (1) Synthesis of potassium tris(tert-butyloxide)tin (KSn(OtBu)3) and (2) Conversion to methyltin tris(tert-butyloxide) This example describes a one-pot, direct synthesis of organotin trialkoxides. The method is based on the following two reactions, the second of which is carried out at room temperature and employs a tetraalkyl (quaternary) ammonium salt as the catalyst. All experiments in this example are carried out in an oxygen-excluded inert atmosphere, such as nitrogen, argon, or other inert atmosphere. (1) SnCl2 + K(OtBu) → KSn(OtBu)3 (2)KSn(OtBu)3+CH3I→MeSn(OtBu)3

[0066] (1) Tin dichloride and anhydrous tetrahydrofuran were added to a reaction vessel under an inert atmosphere to form a solution with a concentration of approximately 0.07 g SnCl / mL THF. The solution was mixed while cooling to 4°C. Then, 2.0 molar equivalents of potassium tert-butyloxide, based on the initial amount of tin dichloride, were slowly added. The reaction mixture was maintained at a temperature below 60°C. Upon completion of the addition step, the reaction mixture was stirred for 1 hour. The resulting white precipitate was removed by filtration on a celite bed, and the filtrate was collected. To the filtrate, additional potassium tert-butyloxide (0.9 molar equivalents, based on the initial amount of tin dichloride) was slowly added. From a processing perspective, 0.9 molar equivalents, based on the initial amount of tin, is approximately 1 molar equivalent of the remaining tin. The reaction mixture was maintained at a temperature below 60°C. Volatiles were removed under vacuum and the reaction product was recrystallized from a 1:1 mixture of THF / toluene (approximately 2 mL / g of reaction product) at −20 °C to give KSn(OtBu) as a white crystalline solid.

[0067] Figure 1 shows the structure of KSn(OtBu)3. 1 The H NMR spectrum shows a single chemical shift: 1 H NMR (400 MHz, THF), δ: 1.17 ppm. Figure 2 shows the structure of KSn(OtBu) 119The Sn NMR spectrum shows a single chemical shift: 119 Sn NMR (149MHz, THF), δ:-183ppm.

[0068] (2) The KSn(OtBu) reaction product (1 molar equivalent) from (1) was mixed with 0.5 molar equivalents of tetrabutylammonium iodide ((n-Bu)N(I)) as a catalyst, and toluene was added to the reaction vessel under an inert atmosphere to obtain a solution with a concentration of approximately 0.10 g KSn(OtBu) / mL toluene. The solution was mixed at room temperature. Next, 1.5 molar equivalents of methyl iodide (CHI) based on the amount of KSn(OtBu) was slowly added, and the reaction mixture was stirred at room temperature for 1 hour. The volatiles were removed under vacuum, and the resulting residue was filtered through a celite bed with pentane. The filtrate was pumped off and distilled to give MeSn(OtBu) as a clear yellow liquid. Figure 3 shows the solubility of the reaction product, MeSn(OtBu) 119 The Sn NMR spectrum is shown, which shows a single peak: 119 Sn NMR (149 MHz, neat), δ: -175. The presence of a single peak in the tin environment suggests that there are no discernible tin by-products in the conversion of KSn(OtBu)3 to MeSn(OtBu)3.

[0069] This example demonstrates a two-step, one-pot method for the straightforward synthesis of organotin trialkoxides with primary Sn-C bonds with high mono-organo selectivity, using commercially available tin dichloride, alkali alkoxide, and alkyl halide reactants.

[0070] Example 2: Synthesis of 2-propyltin tris(tert-butyl oxide) This example describes a one-pot, direct synthesis of organotin trialkoxides. The method is based on the following reaction: The reaction is carried out by the addition of heat and a tetraalkyl (quaternary) ammonium salt as a catalyst. KSn(OtBu)3+(CH3)2CH2I→ i PrSn(OtBu)3

[0071] The reaction product of KSn(OtBu) from Example 1, 0.67 molar equivalents (based on 1 molar equivalent of tin) of tetrabutylammonium iodide ((n-Bu)N(I)) as a catalyst, and toluene were added to a reaction vessel under an inert atmosphere and mixed to form a solution having a concentration of approximately 0.10 g KSn(OtBu) / mL toluene. The solution was mixed at room temperature. Then, 1.5 molar equivalents of 2-iodopropane ((CH)CHI) based on the amount of KSn(OtBu) were slowly added with stirring. The reaction mixture was then heated to 80°C and stirred for 2 days. Thereafter, the volatiles were removed under vacuum, and the residue thus remaining was filtered on a celite bed with pentane. The filtrate was pumped out and distilled to give 2-propyltin tris(tert-butyloxide)( i PrSn(OtBu)3) was obtained as a clear yellow liquid. Figure 4 shows the reaction product. i PrSn(OtBu)3 1 The H NMR spectrum shows the following chemical shifts: 1 H NMR (400 MHz, neat) δ: 1.95 (hept, 1H), 1.56 (d, 6H), 1.48 (s, 27H) ppm. i PrSn(OtBu)3 119 The Sn NMR spectrum is shown, which shows a single peak: 119 Sn NMR (149 MHz, neat), δ: -222 ppm. The fact that tin is in a single peak environment means that KSn(OtBu)3 i This suggests that there are no tin by-products identified in the conversion to PrSn(OtBu)3.

[0072] This example demonstrates a straightforward method for the synthesis of organotin trialkoxides with secondary Sn—C bonds with high mono-organo selectivity.

[0073] Example 3: Synthesis of 1-propyltin tris(tert-butyl oxide) This example demonstrates two methods using different alkyl halides (RX) for the one-pot, direct synthesis of organotin trialkoxides. The reactions are based on the following reaction, except that in Method A, RX is n PrI, and in method B, n The reaction was carried out by adding heat and a tetraalkyl (quaternary) ammonium salt as a catalyst. KSn(OtBu)3+RX→ n PrSn(OtBu)3

[0074] Method A: The reaction product of KSn(OtBu) from Example 1, 0.5 molar equivalents (based on 1 molar equivalent of tin) of tetrabutylammonium iodide ((n-Bu)N(I)) as a catalyst, and toluene were added to a reaction vessel under an inert atmosphere and mixed to form a solution having a concentration of approximately 0.10 g KSn(OtBu) / 1 mL toluene. The solution was mixed at room temperature. Then, 1.3 molar equivalents of 1-iodopropane (based on the amount of KSn(OtBu)) were added. n PrI)2CH2I) was added slowly with stirring. The reaction mixture was then heated to 45°C and stirred for 1 day. Afterwards, the volatiles were removed under vacuum and the residue thus left was filtered over a bed of celite with pentane. The filtrate was pumped off and distilled to give 1-propyltin tris(tert-butyloxide)( n PrSn(OtBu)3) was obtained as a clear yellow liquid. Figure 6 shows the reaction product. n PrSn(OtBu)3 119 The Sn NMR spectrum is shown, which shows a single peak: 119Sn NMR (149 MHz, neat), δ: -197 ppm. The fact that tin is in a single peak environment means that KSn(OtBu)3 n This suggests that there are no tin by-products identified in the conversion to PrSn(OtBu)3.

[0075] Method B: The procedure of Method A was repeated with two differences: 0.4 molar equivalents of tetrabutylammonium iodide was used as the catalyst, and 1.3 molar equivalents of 1-bromopropane (based on the amount of KSn(OtBu)) was used as the alkyl halide reactant. n PrBr) was used. The filtrate was distilled to give 1-propyltin tris(tert-butyloxide) ( n PrSn(OtBu)3) was obtained as a clear yellow liquid. Figure 7 shows the reaction product. n PrSn(OtBu)3 119 The Sn NMR spectrum is shown, which shows a single peak: 119 Sn NMR (149 MHz, neat), δ: -197 ppm. The fact that tin is in a single peak environment means that KSn(OtBu)3 n This suggests that there are no tin by-products identified in the conversion to PrSn(OtBu)3.

[0076] This example demonstrates that it is possible to use different halide groups to directly synthesize organotin trialkoxides with high mono-organo selectivity.

[0077] Example 4: Synthesis of 1-butenyltin tris(tert-butyloxide) (MAL) This example describes a one-pot, direct synthesis of unsaturated organotin trialkoxides. The method is based on the following reaction: The reaction is carried out by the addition of heat and a tetraalkyl (quaternary) ammonium salt as a catalyst. KSn(OtBu)3+(CH3)(H)C=C(H)(CH2Cl)→(CH3)(H)C=C(H)(CH2)Sn(OtBu)3

[0078] The reaction product of KSn(OtBu) from Example 1, 0.1 molar equivalent (based on 1 molar equivalent of tin) of tetrabutylammonium iodide ((n-Bu)N(I)) as a catalyst, and toluene were added to a reaction vessel under an inert atmosphere and mixed to form a solution having a concentration of approximately 0.10 g KSn(OtBu) / 1 mL toluene. The solution was mixed at room temperature. Next, 1.2 molar equivalents of 1-chloro-2-butene ((CH)(H)C=C(H)(CHCl) (a mixture of trans- and cis-isomers in an approximately 70:30 ratio), based on the amount of KSn(OtBu) was slowly added with stirring. The reaction mixture was then heated to 45°C and stirred for 3 days. The volatiles were then removed under vacuum, and the resulting residue was filtered over a bed of Celite with pentane. The filtrate was pumped off and distilled to give the reaction product, (CH)(H)C=C(H)(CH)Sn(OtBu) (1-but-3-enyltin tris(tert-butyloxide), or MAL), as a mixture of trans- and cis-isomers. The reaction product was a clear, yellow liquid.

[0079] Figure 8 shows the reaction product (CH3)(H)C=C(H)(CH2)Sn(OtBu)3 1 The H NMR spectrum shows the following chemical shifts: 1 H NMR (400 MHz, neat) δ: 5.70 (m, 2H), 2.41 (cis) + 2.38 (trans) (m, 2H), 1.87 (m, 3H), 1.48 (cis) + 1.49 (trans) (s, 27H) ppm. Figure 9 shows the identity of (CH3)(H)C=C(H)(CH2)Sn(OtBu)3. 119 The Sn NMR spectrum shows the following chemical shifts: 119Sn NMR (149 MHz, neat) δ: -225 (trans), -227 (cis) ppm. These results indicate that the predominant isomeric species is trans-, where the isomeric ratio of the MAL reaction product preserves that of the 1-chloro-2-butene reactant. The results also suggest that there is no discernible tin by-product in the conversion of KSn(OtBu) to (CH)(H)C=C(H)(CH)Sn(OtBu)

[0080] This example demonstrates a method for the direct synthesis of unsaturated organotin trialkoxides with high mono-organo selectivity. The example also demonstrates that the reaction proceeds with both trans- and cis-isomers of the olefinic halide reactant.

[0081] Example 5: UV-based synthesis of 2,2,2-trifluoroethyltin tris(tert-butyloxide) (TFE) This example demonstrates a one-pot method for the direct synthesis of fluorinated organotin trialkoxides under UV light, based on the following reaction: Sn2(OtBu)4+CF3CH2I→CF3CH2Sn(OtBu)3

[0082] Sn2(OtBu)4, 1.3 molar equivalents (based on 1 molar equivalent of di-tin reactant) of 2,2,2-trifluoroiodoethane (CF3CH2I), and pentane were added to a reaction vessel under an inert atmosphere and mixed to form a solution with a concentration of approximately 0.33 g Sn2(OtBu)4 / mL pentane. The solution was mixed at room temperature. The solution was then irradiated overnight (approximately 15 hours) with ultraviolet light (40 W LED; 365 nm). The reaction mixture was then filtered over a Celite bed, and the volatiles of the filtrate were removed under vacuum. The filtrate was distilled to obtain the final reaction product, CF3CH2Sn(OtBu)3 (2,2,2-trifluoroethyltin tris(tert-butyloxide), or TFE). The reaction product was a clear, yellow liquid.

[0083] Figure 10 shows the reaction product CF3CH2Sn(OtBu)3 1 The H NMR spectrum shows the following chemical shifts: 1 H NMR (400 MHz, neat) δ: 1.77 (m, 2H), 1.06 (s, 27H) ppm. Figure 11 shows the reaction product CF3CH2Sn(OtBu)3. 119 The Sn NMR spectrum shows a single peak: 119 Sn NMR (149 MHz, neat) δ: -231(q) ppm. Figure 12 shows the reaction product CF3CH2Sn(OtBu)3. 19 The F NMR spectrum shows the following chemical shifts: 19 F NMR (neat) δ: -53(m) ppm. These NMR results suggest that there is no discernible tin by-product in the conversion of KSn(OtBu) to CF3CH2Sn(OtBu)3.

[0084] This example demonstrates a photochemical method for the direct synthesis of fluorinated organotin trialkoxides with high mono-organo selectivity.

[0085] Example 6: LED-based synthesis of 2,2,2-trifluoroethyltin tris(tert-butyloxide) (TFE) This example demonstrates a one-pot photochemical method for the direct synthesis of fluorinated organotin trialkoxides under visible (LED) light. The method is based on the following reaction: KSn(OtBu)3+CF3CH2I→CF3CH2Sn(OtBu)3

[0086] Part 1: Considering violet and blue light The KSn(OtBu)3 reaction product from Example 1, 1.1 molar equivalents (based on 1 molar equivalent of tin) of 2,2,2-trifluoroiodoethane (CF3CH2I), and acetonitrile were added to a reaction vessel under an inert atmosphere and mixed to form a solution having a concentration of approximately 0.25 g KSn(OtBu)3 / mL acetonitrile. The solution was mixed at room temperature. The solution was then irradiated with visible light for 1 day while stirring. The visible light was provided by a 100 W LED and included either violet light (approximately 400 nm) or blue light (approximately 460 nm). A fan was used to maintain the outside temperature of the reaction vessel below 30°C. The reaction solvent was then removed under reduced pressure, and the resulting residue was filtered through a bed of Celite using pentane. The volatiles of the filtrate were removed under vacuum, and the resulting oil was distilled to give the final reaction product, CF3CH2Sn(OtBu)3 (2,2,2-trifluoroethyltin tris(tert-butyloxide), or TFE), which was a clear, yellow liquid.

[0087] Figures 13 and 14 show the NMR spectra of the reaction product prepared using violet light. The reaction product prepared using blue light also showed indistinguishable results. Figure 13 shows the NMR spectra of the reaction product CF3CH2Sn(OtBu)3. 1 The H NMR spectrum shows the following chemical shifts: 1H NMR (400 MHz, neat) δ: 1.57 (s, 27H), 2.27 (q, 2H) ppm. Figure 14 shows the reaction product CF3CH2Sn(OtBu)3. 119 The Sn NMR spectrum shows the following chemical shifts: 119 Sn NMR (149 MHz, neat) δ: -231(q) ppm. These results suggest that there are no discernible tin by-products in the conversion of KSn(OtBu) to CF3CH2Sn(OtBu)3.

[0088] Part 2: Considering Green Light A solution was prepared according to Part 1, except that the solution was prepared in a sealed NMR tube (under inert atmosphere) rather than in a reaction vessel. The NMR tube was irradiated with a 100 W green LED (approximately 530 nm) for 3 hours. Conversion of the reaction product to CF3CH2Sn(OtBu)3 was observed as shown in Figure 15. 119 This was confirmed by the disappearance of the KSn(OtBu) signal (δ: -188 ppm) in the Sn NMR. (Note: The reaction product CF3CH2Sn(OtBu)3 in the reaction mixture 119 (The Sn peak was too broad to be observed.) The conversion of the reaction product to CF3CH2Sn(OtBu)3 was further 19 This was also confirmed by the presence of the CF3CH2Sn(OtBu)3 signal in F NMR. As shown in Figure 16, after 1 hour, both the reactant CF3CH2I and the reaction product CF3CH2Sn(OtBu)3 signals were observed, with the reactant signal being stronger. After 3 hours, the relative intensities of the reactant and product signals reversed, which is consistent with the reaction proceeding to completion.

[0089] Part 3: Considering Ambient Light Additional experiments were performed to examine the effect of LED light on the process. A solution of KSn(OtBu)3, 1.5 molar equivalents (based on 1 molar equivalent of tin) of CF3CH2I, and acetonitrile was added to a reaction vessel under an inert atmosphere and mixed to form a solution with a concentration of approximately 0.33 g KSn(OtBu)3 / mL acetonitrile (Solution A). Another solution was prepared similarly to Solution A, except that 0.4 molar equivalents of tetrabutylammonium iodide, based on the amount of KSn(OtBu)3, was added (Solution B). Solutions A and B were each heated to 80°C and stirred for two days. NMR analysis was then performed on each sample. The results indicated that CF3CH2Sn(OtBu)3 was not produced in either sample, indicating that more photons than standard ambient light provides are required to produce the fluorinated trialkoxy reaction product. The results of this study contrast with those shown in Example 2, where a non-fluorinated trialkoxy reaction product was prepared using the same reactants and conditions as solution B.

[0090] This example demonstrates a photochemical method for the direct synthesis of fluorinated organotin trialkoxides with high mono-organo selectivity and high yield. This example further demonstrates that the method is effective with various wavelengths of visible light. This example also demonstrates that the reaction to form the fluorinated trialkoxy reaction product is photochemically promoted.

[0091] Example 7: Synthesis of butyldi-tin hexa(tert-butyloxide) (BDT) This example describes a method for the direct synthesis of organodi-tin trialkoxides, represented by formula 1. The method is based on the following reaction: The reaction is carried out with heat and the addition of a tetraalkyl (quaternary) ammonium salt as a catalyst, and the reaction product is purified by sublimation. KSn(OtBu)3+(CH2I)CH2)2CH2I→C4H8Sn2(OtBu)6 [ka]

[0092] The KSn(OtBu) reaction product from Example 1 (2.1 molar equivalents), tetrabutylammonium iodide ((n-Bu)N(I)) (0.21 molar equivalents) as catalyst, and toluene were added to a reaction vessel under an inert atmosphere and mixed to form a solution with a concentration of 0.5 mmol KSn(OtBu) / mL toluene. The solution was mixed at room temperature. Then, 1.0 molar equivalent of 1,4-diiodobutane (CHI)CHCHI (Ambeed) was slowly added with stirring. The reaction mixture was heated to 60°C and stirred overnight (approximately 15 hours). Volatiles were then removed under vacuum, and the resulting residue was dissolved in pentane. The pentane mixture was then filtered through a bed of Celite. The filtrate was pumped off under reduced pressure to yield a colorless solid. The colorless solid was then stirred overnight in acetonitrile (5 mL / g solid) under an inert atmosphere. Following stirring, the solid was recollected by filtration through a medium-porosity glass filter and washed with a minimal amount of acetonitrile. The collected solid was then dissolved in acetonitrile (10 mL / g solid) by heating to 50 °C. The heated solution was then filtered over Celite into a sealed flask, which was then cooled to -20 °C to allow crystallization for approximately 12 hours. After removing the mother liquor by decantation and evaporation, the crystalline solid was subjected to sublimation under vacuum (60 mTorr) to yield colorless crystals of the reaction product (C4H8Sn2(OtBu)6, Formula 1). Figure 17 shows the crystallization of the reaction product C4H8Sn2(OtBu)6. 1 The H NMR spectrum shows the following chemical shifts: 1H NMR (400 MHz, C6D6) δ: 1.75 (t, 4H), 1.25 (t, 4H), 1.45 (s, 54H, OtBu) ppm. Figure 18 shows the reaction product C4H8Sn2(OtBu)6. 119 The Sn NMR spectrum shows a single peak: 119 Sn NMR (149 MHz, C6D6) δ: -196 ppm. These NMR results suggest that there are no discernible tin by-products in the conversion of KSn(OtBu)3 to C4H8Sn2(OtBu)6.

[0093] This example demonstrates a method for the direct synthesis of organo di-tin trialkoxides having the general formula L3Sn-R-SnL3. This example also demonstrates that sublimation can be effectively used to purify the di-tin compositions.

[0094] Example 8: Synthesis of 1,3,5-tris-(methyltin tris(tert-butyloxide))benzene (MTT) This example describes a method for the direct synthesis of organotri-tin trialkoxides, represented by formula 2. The method is based on the following reaction: The reaction is carried out by adding heat and a tetraalkyl (quaternary) ammonium salt as a catalyst. KSn(OtBu)3+C9H9Br3→C6H3(CH2Sn(OtBu)3)3 [ka]

[0095] The reaction product of KSn(OtBu) from Example 1, 0.1 molar equivalent (based on 1 molar equivalent of tin) of tetrabutylammonium iodide ((n-Bu)N(I)) as a catalyst, and toluene were added to a reaction vessel under an inert atmosphere and mixed to form a solution with a concentration of approximately 0.10 g KSn(OtBu) / mL toluene. The solution was mixed at room temperature. Then, 0.3 molar equivalent (based on the amount of KSn(OtBu)) of 1,3,5-tris-(bromomethyl)benzene (C9H9Br3) was slowly added with stirring. The reaction mixture was then heated to 45°C and stirred overnight (approximately 15 hours). Afterwards, the volatiles were removed under vacuum, and the resulting residue was filtered through a Celite bed with pentane. The filtrate was pumped off and washed with MeCl2, yielding a white solid.

[0096] Figure 19 shows the reaction product (C6H3(CH2Sn(OtBu)3)3) 1 The H NMR spectrum shows the following chemical shifts: 1 H NMR (400 MHz, C6D6) δ: 1.45 (s, 81H), 2.75 (s, 6H), 7.08 (s, 3H) ppm. Figure 20 shows the reaction product (C6H3(CH2Sn(OtBu)3)3). 119 The Sn NMR spectrum shows a single peak: 119 Sn NMR (149 MHz, C6D6) δ: -229 ppm. These results suggest that there is no discernible tin by-product in the conversion of K5n(OtBu)3 to (C6H3(CH2Sn(OtBu)3)3).

[0097] This example demonstrates a method for the direct synthesis of organotritin trialkoxides and suggests that other organopolytin trialkoxides may be prepared in a similar manner.

[0098] Example 9: UV-based synthesis of 3,3,3,4,4,4-hexafluoroisobutyltin tris(tert-butyloxide) (HFB) This example demonstrates a one-pot method for the direct synthesis of fluorinated organotin trialkoxides under UV light, based on the following reaction: Sn2(OtBu)4+(CF3)2CHCH2I→(CF3)2CHCH2Sn(OtBu)3 [ka]

[0099] In a reaction vessel under an inert atmosphere, Sn2(OtBu)4 was mixed with pentane to form a solution having a concentration of approximately 0.33 g Sn2(OtBu)4 / 1 mL pentane. The mixture was cooled to -40 °C. 1.3 molar equivalents (based on 1 molar equivalent of di-tin reactant) of (CF3)2CHCH2I was then added to the reaction vessel with stirring. The solution was irradiated with ultraviolet light (40 W LED; 365 nm) with mixing for approximately 12 hours, while maintaining the reaction temperature below -30 °C. The reaction mixture was then further diluted with pentane (5 mL pentane / 1 mL mixture) to form a diluted crude mixture, which was then held at -20 °C for 24 hours. The reaction mixture was then filtered over a bed of Celite, and the volatiles of the filtrate were removed under vacuum. The filtrate thus obtained was distilled to give the final reaction product (CF)CHCHSn(OtBu) (3,3,3,4,4,4-hexafluoroisobutyltin tris(tert-butyloxide) or HFB), represented by Equation 3. The reaction product was a clear, yellow liquid.

[0100] Figure 21 shows the reaction product (CF3)2CHCH2Sn(OtBu)3 1 1 H NMR spectrum, which shows the following chemical shifts: 1 H NMR (400 MHz, CD) δ: 3.58 (m, 1H), 1.46 (d, 2H), 1.33 (2, 27H), 1.06 (s, 27H) ppm. Figure 22 shows the reaction product (CF)CHCHSn(OtBu) 119The Sn NMR (149 MHz, CD) spectrum shows a major peak at δ: -219.23 (corresponding to the reaction product compound (CF)CHCHSn(OtBu)), and minor peaks at δ: -372.81 and δ: -87.33 (corresponding to dialkyltin and tin tetraalkoxide impurities, respectively). The high integration of the reaction product relative to the impurities indicates a high purity of the (CF)CHCHSn(OtBu) reaction product. Figure 23 shows the cleavage of the reaction product (CF)CHCHSn(OtBu) 19 F NMR spectrum, which shows a single sharp peak: 19 F NMR (376 MHz, neat) δ: -69.2 ppm. 19 F NMR indicates a single fluorine environment.

[0101] This example demonstrates a photochemical method for the direct synthesis of polyfluorinated organotin trialkoxides with high mono-organo selectivity.

[0102] Example 10: UV-based synthesis of 4,5,5,5,6,6,6-heptafluoropentyltin tris(tert-butyloxide) (HFP) This example demonstrates a one-pot method for the direct synthesis of fluorinated organotin trialkoxides under UV light, based on the following reaction: Sn2(OtBu)4+(CF3)2CF(CH2)2I→(CF3)2CF(CH2)2Sn(OtBu)3 [ka]

[0103] The procedure of Example 9 was followed, except that the reaction was carried out with (CF)CF(CH)I instead of (CF)CHCHI. The filtrate thus obtained was distilled to give the final reaction product (CF)CF(CH)Sn(OtBu) (4,5,5,5,6,6,6-heptafluoropentyltin tris(tert-butyloxide), or HFP), represented by Equation 4.

[0104] This example demonstrates a photochemical method for the direct synthesis of polyfluorinated organotin trialkoxides with expected high mono-organo selectivity.

[0105] The above-described embodiments are illustrative and not limiting. Additional embodiments exist within the claims. In addition, while the present invention has been described with reference to specific embodiments, those skilled in the art will readily recognize that changes can be made in form and detail without departing from the spirit and scope of the present invention. Any incorporation of the above-referenced documents is limited and does not incorporate any subject matter contrary to the express disclosure herein. To the extent that particular structures, compositions, and / or processes are described herein using components, elements, ingredients, or other partitions, unless otherwise specified, the disclosure herein should be understood to cover, in certain embodiments, embodiments that include the particular components, elements, ingredients, other partitions, or combinations thereof, as well as embodiments that consist essentially of such particular components, elements, ingredients, other partitions, or combinations thereof, including additional features that do not alter the basic essence of the subject matter as suggested in the description. The use of the term "about" herein refers to the expected uncertainty in the associated numerical values, as would be understood in the particular context by one of ordinary skill in the art.

Claims

1. 1. A method for synthesizing monoorganotin trialkoxides, said method comprising: MSn(OR') ３ RX ｎ and reacting with R[Sn(OR') ３ ] ｎ wherein M is Li, Na, K, Rb, or Cs; X is Cl, Br, or I; n≧1; R is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond; and R′ is an organic group having 1 to 10 carbon atoms, wherein said organic group may optionally contain heteroatoms and / or unsaturated bonds.

2. The method of claim 1 , wherein n=1.

3. 3. The method of claim 2, wherein R comprises one or more fluorine atoms.

4. 4. The method of claim 2 or claim 3, wherein R comprises a C=C group.

5. 2. The method of claim 1, wherein n=2.

6. 6. The method of claim 5, wherein R contains 3 to 12 carbon atoms.

7. 7. The method of claim 5 or claim 6, wherein R comprises an unsaturated group.

8. 2. The method of claim 1, wherein n=3.

9. The method of claim 8 , wherein R comprises an aromatic group.

10. 10. The method of claim 1, wherein X is Br or I and M is K.

11. The method of any one of claims 1 to 10, wherein the reaction is carried out within about 2 days.

12. The process of any one of claims 1 to 11, wherein the reaction is carried out at a temperature of from about -20°C to about 100°C.

13. 13. The process according to any one of claims 1 to 12, wherein the reaction is carried out using a quaternary ammonium catalyst and / or a phosphonium catalyst.

14. 14. The method of claim 13, wherein the catalyst is tetrabutylammonium halide.

15. 15. The method of claim 14, wherein the halide is I.

16. 16. The method of any one of claims 1 to 15, wherein the reaction is carried out under a direct visible or ultraviolet light source.

17. The method of claim 16 , wherein the light source is monochromatic.

18. Using distillation, R[Sn(OR′) ３ ] ｎ The method of any one of claims 1 to 17, further comprising purifying the reaction product.

19. Using sublimation, R[Sn(OR′) ３ ] ｎ The method of any one of claims 1 to 18, further comprising purifying the reaction product.

20. The MSn(OR′) ３ However, SnX' ２ and MOR', where X' is Cl, Br, or I, and MSn(OR') ３ However, without being isolated, RX ｎ The method according to any one of claims 1 to 19, wherein the compound is reacted with

21. 21. The method of any one of claims 1 to 20, wherein the carbon bonded to Sn is a primary carbon (only one C-C bond) or a secondary carbon (two C-C bonds).

22. A method for synthesizing monoorganotin trialkoxides, the method comprising: ２ (OR') ４ is reacted with RX to give RSn(OR') ３ wherein X is Cl, Br, or I; R is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond; and R′ is an organic group having 1 to 10 carbon atoms, wherein said organic group may optionally contain heteroatoms and / or unsaturated bonds.

23. 23. The method of claim 22, wherein R comprises a fluorine atom.

24. R is -CF ３ 23. The method of claim 22, comprising a group.

25. The method of any one of claims 22 to 24, wherein the ultraviolet light has a wavelength of from about 315 nm to about 400 nm.

26. The method of any one of claims 22 to 25, wherein R' is a methyl, ethyl, propyl, i-propyl, t-butyl, i-butyl, or t-amyl group.

27. The reaction product was filtered to remove Sn ２ X ２ (OR') ２ 27. The method of any one of claims 22 to 26, further comprising removing precipitated by-products of

28. 28. The method of any one of claims 22 to 27, wherein the reaction is carried out at a temperature of from about -20°C to about 80°C.

29. Formula ((R'O) ３ Sn) ｎ -R, wherein n≧3, R′ is an organic group having 1 to 10 carbon atoms, and R is an organic group having 5 to 31 carbon atoms, which forms a C—Sn bond with each Sn atom.

30. 30. The organometallic compound of claim 29, wherein n is 3.

31. 31. The organometallic compound of claim 29 or claim 30, wherein R comprises one or more fluorine atoms.

32. 32. The organometallic compound of any one of claims 29 to 31, wherein R comprises an unsaturated group.

33. 32. The organometallic compound of any one of claims 29 to 31, wherein R comprises an aromatic group.

34. 34. The organometallic compound of any one of claims 29 to 33, wherein R' is a methyl, ethyl, propyl, i-propyl, t-butyl, i-butyl, or t-amyl group.

35. 30. The organometallic compound of claim 29, wherein the compound comprises 1,3,5-tris-(methyltin tris(tert-butyloxide))benzene.

36. A solution comprising an organic solvent and the organometallic compound of any one of claims 29 to 35.

37. 37. The solution of claim 36, wherein the organic solvent comprises an alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester, an ether, a ketone, or a combination thereof, and the solution has a concentration of about 0.0025 M to about 1.4 M based on the concentration of tin.

38. 37. The solution of claim 36, wherein the organic solvent comprises a primary alcohol.

39. 37. The solution of claim 36, wherein the organic solvent comprises an aromatic solvent.

40. Formula R ａ SnL ３ wherein L is a hydrolyzable ligand, and R ａ is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond.

41. 36. A structure comprising a radiation-patternable film and a substrate, wherein the film comprises the organometallic compound of any one of claims 29 to 35 and / or a hydrolysis reaction product of the organometallic compound of any one of claims 29 to 35.

42. A structure comprising a radiation-patternable film and a substrate, wherein the film is formed from the compound of any one of claims 29 to 35 and comprises Sn—C bonds.

43. 43. The structure of claim 42, wherein the film further comprises Sn-O-Sn and Sn-OH bonds.

44. Formula (CF ３ ) RSn(OR') ３ wherein R is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond; and R′ is an organic group having 1 to 10 carbon atoms, said method comprising: Under visible or ultraviolet light, (CF ３ ) RX, Sn ２ (OR') ４ or MSn(OR') ３ wherein X is Cl, Br, or I.

45. The method comprises: ３ ) RX to Sn ２ (OR') ４ 45. The method of claim 44, comprising reacting

46. The method comprises the steps of: ３ ) RX to MSn (OR') ３ 45. The method of claim 44, comprising reacting

47. 47. The method of any one of claims 44 to 46, wherein X is I.

48. 47. The method of any one of claims 44 to 46, wherein X is Br.

49. R is CH ２ The method according to any one of claims 44 to 48, wherein the aryl group is a group.

50. R is CR １ R ２ is a group, wherein R １ and / or R ２ The method of any one of claims 44 to 48, wherein is a halogenated organic group having 1 to 5 carbon atoms.

51. 49. The method of any one of claims 44 to 48, wherein R comprises a C=C group.

52. 52. The method of any one of claims 44 to 51, wherein R' is a methyl, ethyl, propyl, i-propyl, t-butyl, i-butyl, or t-amyl group.

53. 53. The method of any one of claims 44 to 52, wherein the visible light is monochromatic.

54. 54. The method of any one of claims 44 to 53, wherein the visible light comprises violet, blue, or green light.

55. 55. The method of any one of claims 44 to 54, wherein the ultraviolet light has a wavelength of from about 315 nm to about 400 nm.

56. 56. The method of any one of claims 44 to 55, wherein the visible or ultraviolet light is provided using an LED.

57. 57. The method of any one of claims 44 to 56, wherein the reaction is carried out within about 2 days.

58. 58. The method of any one of claims 44 to 57, wherein the reaction is carried out at a temperature of from about -20°C to about 80°C.

59. Formula (CF ３ ) ２ R １ C-R ０ Sn(OR') ３ where R ０ is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond; R １ is a hydrogen, halogen atom, or an organic group having 1 to 10 carbon atoms; and R' is an organic group having 1 to 10 carbon atoms.

60. R １ 60. The fluorinated organometallic compound of claim 59, wherein is F.

61. R １ But, -CF ３ 60. The fluorinated organometallic compound of claim 59, comprising a group.

62. R １ 60. The fluorinated organometallic compound of claim 59, wherein is hydrogen.

63. 63. The fluorinated organometallic compound of any one of claims 59 to 62, wherein R' is a methyl, ethyl, propyl, i-propyl, t-butyl, i-butyl, or t-amyl group.

64. R ０ However, (CH ２ ) ｎ and n is 1 to 4.

65. A solution comprising an organic solvent and a fluorinated organometallic compound according to any one of claims 59 to 64.

66. 66. The solution of claim 65, wherein the organic solvent comprises an alcohol, an aromatic hydrocarbon, an aliphatic hydrocarbon, an ester, an ether, a ketone, or a combination thereof, and the solution has a concentration of about 0.0025 M to about 1.4 M based on the concentration of tin.

67. 66. The solution of claim 65, wherein the organic solvent comprises a primary alcohol.

68. Formula R ａ SnL ３ and different from the fluorinated organometallic compound, wherein L is a hydrolyzable ligand; and R ａ is an organic group having 1 to 31 carbon atoms and forming a C—Sn bond.

69. 68. A structure comprising a radiation-patternable film and a substrate, wherein the film comprises the fluorinated organometallic compound of claim D and / or the hydrolysis reaction product of the fluorinated organometallic compound of any one of claims 65-67.

70. 68. A structure comprising a radiation-patternable film and a substrate, wherein the film is formed from the compound of any one of claims 65 to 67 and comprises Sn—C bonds.

71. 71. The structure of claim 70, wherein the film further comprises Sn-O-Sn and Sn-OH bonds.

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