Synthesis methods for amino(halo)silanes
09701695 ยท 2017-07-11
Assignee
Inventors
- Glenn KUCHENBEISER (Newark, DE, US)
- Venkateswara R. Pallem (Hockessin, DE)
- Guillaume Husson (Newark, DE)
Cpc classification
International classification
Abstract
Disclosed are methods of synthesizing an amino(halo)silane comprising the step of reacting a halosilane having the formula Si.sub.aH.sub.bX.sub.c with an aminosilane having the formula Si.sub.dH.sub.e(NR.sup.1R.sup.2).sub.f to produce the amino(halo)silane having the formula Si.sub.wH.sub.xX.sub.y(NR.sup.1R.sup.2).sub.z, wherein X=Br or I; each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group; a, d, and w independently=1 to 4; b+c=2a+2; b=1 to 2a+1; c=1 to 2a+1; e+f=2d+2; e=1 to 2d+1; f=1 to 2d+1; x+y+z=2w+2; and R.sup.1 and R.sup.2 may be joined to form a nitrogen-containing heterocycle.
Claims
1. A method of synthesizing an aminohalosilane, the method comprising reacting a halosilane having the formula
Si.sub.aH.sub.bX.sub.c with an aminosilane having the formula
Si.sub.dH.sub.e(NR.sup.1R.sup.2).sub.f to produce the aminohalosilane reaction product having the formula:
Si.sub.wH.sub.xX.sub.y(NR.sup.1R.sup.2).sub.z wherein X=Br or I; each R.sup.1 and R.sup.2 independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group; a, d, and w=1 to 4; b+c=2a+2; b=1 to 2a+1; c=1 to 2a+1; e+f=2d+2; e=1 to 2d+1; f=1 to 2d+1; x+y+z=2w+2; x=1 to 2w; y=1 to 2w; z=1 to 2w; and R.sup.1 and R.sup.2 may be joined to form a nitrogen-containing heterocycle.
2. The method of claim 1, wherein a molar ratio of the halosilane and the aminosilane ranges from approximately 10:1 to 1:10.
3. The method of claim 1, further comprising isolating the aminohalosilane reaction product from a crude product produced by the reaction.
4. The method of claim 1, further comprising distilling the aminohalosilane reaction product.
5. The method of claim 1, further comprising subliming the aminohalosilane reaction product.
6. The method of claim 1, wherein X=I.
7. The method of claim 6, wherein the halosilane is SiH.sub.2I.sub.2.
8. The method of claim 1, wherein X=Br.
9. The method of claim 8, wherein the halosilane is SiH.sub.2Br.sub.2.
10. The method of claim 1, wherein a=d and b=e.
11. The method of claim 10, wherein the method produces a single aminohalosilane reaction product and no byproducts.
12. The method of claim 1, wherein the reaction is performed in a solvent.
13. The method of claim 1, wherein the reaction does not utilize a solvent.
14. A method of synthesizing an aminohalosilane comprising the steps of: adding a dibromosilane or diiodosilane to a reactor; adding an aminosilane having the formula Si.sub.dH.sub.e(NR.sup.1R.sup.2).sub.f to the reactor to produce a mixture, wherein each R.sup.1 and R.sup.2 independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group; d=1 to 4; e+f=2d+2; e=1 to 2d+1; and f=1 to 2d+1; stirring the mixture to form a stirred mixture; and isolating the aminohalosilane from the stirred mixture.
15. The method of claim 14, wherein d=1 and e=2.
16. The method of claim 15, wherein the method produces a single aminohalosilane reaction product and no byproducts.
17. The method of claim 14, wherein the reaction is performed in a solvent.
18. The method of claim 14, wherein the reaction does not utilize a solvent.
19. The method of claim 14, further comprising distilling the aminohalosilane reaction product.
20. The method of claim 14, further comprising subliming the aminohalosilane reaction product.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description, taken in conjunction with the accompanying drawings, in which like elements are given the same or analogous reference numbers and wherein:
(2)
(3)
(4)
(5)
(6)
(7)
DESCRIPTION OF PREFERRED EMBODIMENTS
(8) Methods of synthesizing aminohalosilanes are disclosed. A halosilane having the formula
Si.sub.aH.sub.bX.sub.c
is reacted with an aminosilane having the formula
Si.sub.dH.sub.e(NR.sup.1R.sup.2).sub.f
to produce the aminohalosilane reaction product having the formula:
Si.sub.wH.sub.xX.sub.y(NR.sup.1R.sup.2).sub.z
wherein X=Br or I; each R.sup.1 and R.sup.2 independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group; a, d, and w independently=1 to 4; b+c=2a+2; b=1 to 2a+1; c=1 to 2a+1; e+f=2d+2; e=1 to 2d+1; f=1 to 2d+1; x+y+z=2w+2; x=1 to 2w; y=1 to 2w; z=1 to 2w; and R.sup.1 and R.sup.2 may be joined to form a nitrogen-containing heterocycle.
(9) The disclosed methods employ a direct ligand exchange, which exchanges the X and NR.sup.1R.sup.2 ligands between the halosilane and aminosilane reactants. The H do not exchange.
(10) Unlike the prior art reaction between halosilanes and amines, the disclosed methods do not produce any salt byproducts. Salt contamination and/or impurities may cause degradation of the resulting aminohalosilane reaction product. As semiconductor manufacturing requires high purity components, the ability to produce the aminohalosilane reaction products with no salt byproduct formation is beneficial.
(11) As will be seen in the Examples that follow, the disclosed processes also produce high yields. When a=d, b=e, and the halosilane and aminosilane quantities are stoichiometrically proportional, the disclosed methods may produce one aminohalosilane reaction product, rendering obsolete the need for subsequent isolation of the reaction product from the reactants or any secondary reaction products. As a result, the disclosed methods have improved atom economy over the prior art methods because every atom in the reactant is also contained in the product. The atom economy also helps reduce waste and any further processing steps required by the prior art.
(12) Under an inert atmosphere, the halosilane is added to a reactor at a temperature ranging from approximately 100 C. to approximately 100 C., preferably ranging from approximately 78 C. to approximately 60 C., more preferably ranging from approximately 40 C. to approximately 50 C., more preferably from approximately 25 C. to approximately 35 C., and even more preferably at approximately 0-25 C. The inert atmosphere utilized may include Ar, N.sub.2, He, or Kr.
(13) The aminosilane is then added to the flask to produce a mixture of the halosilane and aminosilane at a temperature ranging from approximately 100 C. to approximately 100 C. The aminosilane may be pre-chilled or pre-heated to the temperature equal to the temperature of the halosilane in the flask.
(14) Alternatively, the aminosilane may be first added to the reactor under an inert atmosphere, followed by the halosilane.
(15) The molar ratio of halosilane to aminosilane may range from approximately 10:1 to approximately 1:10 as needed to optimize the formation of the desired product and/or to simplify the purification of the desired product.
(16) The reaction may be performed solvent free or may employ a solvent which may include but is not limited to: pentane, hexane, heptane, diethyl ether, dibutyl ether, toluene, tetrahydrofuran (THF), 2-methyltetrahydrofuran, diglyme, dichloromethane, chloroform, anisole, benzene, or acetonitrile. When one or both of the reactants and the aminohalosilane reaction product are all liquids or low melting point solids (i.e. 23-50 C.), the process is preferably performed without a solvent, which shortens the synthesis process and may also reduce the concentration of impurities in the reaction product.
(17) The mixture is subsequently allowed to warm to room temperature and may be stirred for approximately 1 hour to approximately 48 hours at room temperature. The stirred mixture is a cloudy liquid comprising aminohalosilane, unreacted halosilane, and possible impurities.
(18) When the aminohalosilane reaction product is a solid, the stirred mixture may be filtered to remove impurities and obtain the aminohalosilane reaction product. The product may be extracted using a solvent, such as pentane. Typical filters include glass or polymer fritted filters. The aminohalosilane reaction product may then be isolated using sublimation at a temperature range above room temperature, preferably at a range from 25 C. to 150 C., more preferably at a range from 30 C. to 120 C., even more preferably at a range from 50 C. to 70 C. Alternatively, the aminohalosilane reaction product may be isolated using sublimation at reduced pressure, preferably at a range from approximately 30 mTorr to approximately 750 Torr. In another alternative, sublimation may occur under both elevated temperature and reduced pressure.
(19) Alternatively, when the aminohalosilane reaction product is a liquid, the stirred mixture may be filtered to remove solid byproducts. A filtration agent such as anhydrous diatomaceous earth may be employed to improve the process. Typical filters include glass or polymer frit filters. This step may be sufficient to produce the reaction product.
(20) Occasionally, the filtrate may need further processing. For example, when the filtrate yields a heterogeneous suspension of solid material, the filtrate may then be distilled over a short path column to yield the aminohalosilane reaction product through a flash distillation process that removes some or all of the non-desired reaction products or impurities. Alternatively, the aminohalosilane reaction product may be isolated from the filtrate through a distillation column or by heating the filtrate to approximately the boiling point of the aminohalosilane. In another alternative, both the flash process and the distillation column may be necessary. One of ordinary skill in the art will recognize that the boiling point of the warmed stirred mixture will change as the aminohalosilane reaction product is isolated from the warmed stirred mixture and adjust the recovery temperature accordingly. Any unreacted halosilane may be vented through a distillation column. One of ordinary skill in the art will recognize that the vented halosilane may be recovered for later use or disposal.
(21) The disclosed methods may convert approximately 80% mol/mol to approximately 90% mol/mol of the halosilane to the aminohalosilane reaction product. The isolated the aminohalosilane reaction product has a purity ranging from approximately 50% mol/mol to approximately 90% mol/mol.
(22) The aminohalosilane reaction product may be further purified by distillation or sublimation. The purified the aminohalosilane reaction product has a purity ranging from approximately 97% mol/mol to approximately 100% mol/mol, preferably from approximately 99% mol/mol to approximately 100% mol/mol. The purified aminohalosilane reaction product preferably comprises between the detection limit and 100 ppbw of each potential metal contaminant (e.g., at least Al, Ca, Cr, Cu, Fe, Mg, Ni, K, Na, Ti, Zn, etc.). Suitable distillation methods include atmospheric fractional distillation or batch fractional distillation or vacuum fractional distillation. The batch fractional distillation may be performed at low temperature and pressure, but is preferably performed at atmospheric pressure. Alternatively, the the aminohalosilane reaction product may be purified by continuous distillation over two distillation columns to separate the aminohalosilane reaction product from both low and high boiling impurities in sequential steps.
(23) As shown in the examples below, the purified product may be analyzed by gas chromatography mass spectrometry (GCMS) which shows its purity. The structure of the product may be confirmed by .sup.1H, .sup.13C and/or .sup.29Si NMR.
(24) One of ordinary skill in the art will recognize the sources for the equipment components of the systems used to practice the disclosed methods. Some level of customization of the components may be required based upon the desired temperature range, pressure range, local regulations, etc. Exemplary equipment suppliers include Buchi Glas Uster AG, Shandong ChemSta Machinery Manufacturing Co. Ltd., Jiangsu Shajabang Chemical Equipment Co. Ltd, etc. Preferably the components are made of corrosion resistant materials, such as stainless steel, glass lined steel, steel with corrosion resistant liners, etc.
(25) The halosilane has the formula Si.sub.aH.sub.bX.sub.c, wherein a=1-4; b+c=2a+2; b=1 to 2a+1; and c=1 to 2a+1. Preferably, c=2 or 3. Exemplary halosilanes include SiH.sub.2Br.sub.2, SiH.sub.2I.sub.2, SiHBr.sub.3, SiHI.sub.3, Si.sub.2H.sub.4I.sub.2, Si.sub.2H.sub.4Br.sub.2, Si.sub.2H.sub.3I.sub.3, and Si.sub.2H.sub.3Br.sub.3. SiH.sub.2I.sub.2, SiHBr.sub.3, SiHI.sub.3 are commercially available. SiH.sub.2Br.sub.2 may be synthesized as disclosed by Sato et al. in JP62070219. The synthesis of the Si.sub.2H.sub.bX.sub.c is disclosed by Hassler et al. in J Organometallic Chemistry (1993) 460(2), pp. 149-153. One of ordinary skill in the art will recognize that the Si.sub.3H.sub.bX.sub.c and Si.sub.4H.sub.bX.sub.c reactants may also be produced by modification of Hassler's methods. Alternatively, the halosilane reactant may be synthesized by reacting Si.sub.aH.sub.2a+2 with X.sub.2, BX.sub.3, HX with an AlX.sub.3 catalyst.
(26) As the halosilanes may degrade with time to dihalosilanes and trihalosilanes, care should be taken to ensure that the halosilane reactant has a purity ranging from approximately 90% mol/mol to approximately 100% mol/mol. Preferably, the halosilane has a purity ranging from approximately 95% mol/mol to approximately 100% mol/mol, and more preferably from approximately 98% mol/mol to approximately 100% mol/mol. Halosilane reactants having a dihalosilane content of approximately 10% mol/mol to approximately 90% mol/mol lead to low yields of amino(halo)silane due to formation of monohalosilyl disilylamine and polysilazanes. Therefore, the dihalosilane content in any halosilane reactant may range from approximately 0% mol/mol to approximately 10% mol/mol, preferably from approximately 0% mol/mol to approximately 5% mol/mol, and more preferably from approximately 0% mol/mol to approximately 1% mol/mol.
(27) The aminosilane has the formula Si.sub.dH.sub.e(NR.sup.1R.sup.2).sub.f, wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group; d=1-4, e+f=2d+2; e=1 to 2d+1; and f=1 to 2d+1. Preferably, f=2 or 3. Exemplary aminosilanes include bis(diisopropylamino)silane [SiH.sub.2(N(iPr).sub.2).sub.2] or bis(dibutylamino)silane [SiH.sub.2(NiBu.sub.2).sub.2]. These aminosilanes are commercially available or may be synthesized by (1) reacting RLi with R.sup.1R.sup.2NH to form LiNR.sup.1R.sup.2 and mixing c equivalents of LiNR.sup.1R.sup.2 with Si.sub.aH.sub.bX.sub.c to produce Si.sub.aH.sub.b(NR.sup.1R.sup.2).sub.c or (2) reacting 2c equivalents of HNR.sup.1R.sup.2 with Si.sub.aH.sub.bX.sub.c to produce Si.sub.aH.sub.b(NR.sup.1R.sup.2).sub.c. The Si.sub.aH.sub.b(NR.sup.1R.sup.2).sub.c is purified to remove any traces of Li, H.sub.2NR.sub.2.sup.+ or I or Br salts, which may catalyze the decomposition of the Si.sub.aH.sub.b(NR.sup.1R.sup.2).sub.c. Preferably, the aminosilane has a purity ranging from approximately 95% mol/mol to approximately 100% mol/mol, and more preferably from approximately 98% mol/mol to approximately 100% mol/mol. The Li, H.sub.2NR.sub.2.sup.+ or I or Br salts content may range from approximately 0% mol/mol to approximately 10% mol/mol, preferably from approximately 0% mol/mol to approximately 5% mol/mol, and more preferably from approximately 0% mol/mol to approximately 1% mol/mol.
(28) The halosilane or aminosilane may be mixed with a solvent, particularly if either is a solid. The ratio of solvent to halosilane or aminosilane is chosen from the range of approximately 3 mL to approximately 20 mL of the solvent per approximately 1 g of the halosilane or aminosilane, preferably approximately 6 mL to approximately 8 mL of the solvent per approximately 1 g of the halosilane or aminosilane. One of ordinary skill in the art will recognize that a neat, non-solvent process may still be performed if only one of the halosilane or aminosilane is a solid.
(29) The solvent may be selected from arenes, alkanes, alkenes, cycloalkanes or alkyne-based compounds. The selected solvent is not reactive with any of the reactants or products. Furthermore, the solvent must be a liquid at the reaction temperature. Therefore, the selected solvent remains a liquid at temperatures ranging between 100 C. and the boiling point of the solvent. Finally, the solvent must be dry in order to prevent the formation of oxygenated species, such as disiloxanes. The solvent may contain between approximately 0 ppmv and approximately 100 ppmv moisture, and preferably between approximately 0 ppmv and approximately 10 ppmv moisture.
(30) Exemplary solvents include hexane, toluene, heptane, ethylbenzene, or one or more of the xylenes. The xylenes are 1,2-dimethylbenzene, 1,3-dimethylbenzene, and 1-4-dimethylbenzene. Preferably, the solvents are hexane or toluene because they do not freeze at 78 C. Other solvents having properties similar to hexane and toluene are also preferable in the disclosed methods.
(31) The following is a list of exemplary aminohalosilane reaction products produced by the disclosed synthesis methods.
(32) When X=Br, w=1, x=2, y=1, and z=1, the exemplary reaction is SiH.sub.2Br.sub.2+SiH.sub.2(NR.sup.1R.sup.2).sub.2.fwdarw.
(33) ##STR00001##
wherein R.sup.1 and R.sup.2 is selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(34) Exemplary aminohalosilanes having the formula SiH.sub.2Br(NR.sup.1R.sup.2) include:
(35) ##STR00002##
(36) When X=Br, w=1, x=1, y=2, and z=1, the exemplary reaction is 2 SiHBr.sub.3+SiH(NR.sup.1R.sup.2).sub.3.fwdarw.
(37) ##STR00003##
wherein R.sup.1 and R.sup.2 is selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero groups. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(38) Exemplary aminohalosilanes having the formula SiHBr.sub.2(NR.sup.1R.sup.2) include:
(39) ##STR00004##
(40) When X=Br, w=1, x=1, y=1, and z=2, the exemplary reaction is SiHBr.sub.3+2 SiH(NR.sup.1R.sup.2).sub.3.fwdarw.
(41) ##STR00005##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(42) Exemplary aminohalosilanes having the formula SiHBr(NR.sup.1R.sup.2).sub.2 include:
(43) ##STR00006##
(44) When X=Br, w=1, x=0, y=3, and z=1, the exemplary reaction is 3 SiBr.sub.4+Si(NR.sup.1R.sup.2).sub.4.fwdarw.
(45) ##STR00007##
wherein R.sup.1 and R.sup.2 is selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(46) Exemplary aminohalosilanes having the formula SiBr.sub.3(NR.sup.1R.sup.2) include:
(47) ##STR00008##
(48) When X=Br, w=1, x=0, y=2, and z=2, the exemplary reaction is SiBr.sub.4+Si(NR.sup.1R.sup.2).sub.4.fwdarw.
(49) ##STR00009##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(50) Exemplary aminohalosilanes having the formula SiBr.sub.2(NR.sup.1R.sup.2).sub.2 include:
(51) ##STR00010##
(52) When X=Br, w=1, x=0, y=1, and z=3, the exemplary reaction is SiH.sub.2Br.sub.2+Si(NR.sup.1R.sup.2).sub.4.fwdarw.
(53) ##STR00011##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. One of ordinary skill in the art will recognize that SiH.sub.2Br(NR.sup.1R.sup.2) will also be formed.
(54) Exemplary aminohalosilanes having the formula SiBr(NR.sup.1R.sup.2).sub.3 include:
(55) ##STR00012##
(56) When X=I, w=1, x=2, y=1, and z=1, the exemplary reaction is SiH.sub.2I.sub.2+SiH.sub.2(NR.sup.1R.sup.2).sub.2.fwdarw.
(57) ##STR00013##
wherein R.sup.1 and R.sup.2 is selected from C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(58) Exemplary aminohalosilanes having the formula SiH.sub.2I(NR.sup.1R.sup.2) include:
(59) ##STR00014##
(60) When X=I, w=1, x=1, y=2, and z=1, the exemplary reaction is 2 SiHI.sub.3+SiH(NR.sup.1R.sup.2).sub.3.fwdarw.
(61) ##STR00015##
wherein R.sup.1 and R.sup.2 is selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(62) Exemplary aminohalosilanes having the formula SiHI.sub.2(NR.sup.1R.sup.2) include:
(63) ##STR00016##
(64) When X=1, w=1, x=1, y=1, and z=2, the exemplary reaction is SiHI.sub.3+2 SiH(NR.sup.1R.sup.2).sub.3.fwdarw.
(65) ##STR00017##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product
(66) Exemplary aminohalosilanes having the formula SiHI(NR.sup.1R.sup.2).sub.2 include:
(67) ##STR00018##
(68) When X=1, w=1, x=0, y=3, and z=1, the exemplary reaction is 3 SiI.sub.4+Si(NR.sup.1R.sup.2).sub.4.fwdarw.
(69) ##STR00019##
wherein R.sup.1 and R.sup.2 is selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. Preferably, as shown in Comparative Example 1, at least one of R.sup.1 or R.sup.2 is C.sub.2-C.sub.10. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(70) Exemplary aminohalosilanes having the formula SiI.sub.3(NR.sup.1R.sup.2) include:
(71) ##STR00020##
(72) When X=I, w=1, x=0, y=2, and z=2, the exemplary reaction is SiI.sub.4+Si(NR.sup.1R.sup.2).sub.4.fwdarw.
(73) ##STR00021##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(74) Exemplary aminohalosilanes having the formula SiI.sub.2(NR.sup.1R.sup.2).sub.2 include:
(75) ##STR00022##
(76) When X=I, w=1, x=0, y=1, and z=3, the exemplary reaction is SiH.sub.2I.sub.2+Si(NR.sup.1R.sup.2).sub.4.fwdarw.
(77) ##STR00023##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. One of ordinary skill in the art will recognize that SiH.sub.2Br(NR.sup.1R.sup.2) will also be formed.
(78) Exemplary aminohalosilanes having the formula SiI(NR.sup.1R.sup.2).sub.3 include:
(79) ##STR00024## ##STR00025##
(80) When X=I, w=2, x=4, y=1, and z=1, the exemplary reaction is Si.sub.2H.sub.4I.sub.2+Si.sub.2H.sub.4(NR.sup.1R.sup.2).sub.2.fwdarw.
(81) ##STR00026##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product. Alternatively, as shown in the examples that follow, the halosilane may be SiH.sub.2I.sub.2, but multiple reaction products are formed.
(82) Exemplary aminohalodisilanes having the formula Si.sub.2H.sub.4I(NR.sup.1R.sup.2) include:
(83) ##STR00027##
(84) When X=Br, w=2, x=4, y=1, and z=1, the exemplary reaction is Si.sub.2H.sub.4Br.sub.2+Si.sub.2H.sub.4(NR.sup.1R.sup.2).sub.2.fwdarw.
(85) ##STR00028##
wherein each R.sup.1 and R.sup.2 is independently selected from a C.sub.1-C.sub.10 alkyl, aryl, or hetero group. When stoichiometric quantities of the reactants are used, the process produces one reaction product.
(86) Exemplary aminohalodisilanes having the formula Si.sub.2H.sub.4Br(NR.sup.1R.sup.2) include:
(87) ##STR00029##
(88) Exemplary aminohalosilane reaction products may be selected from SiH.sub.2Br(N(Et).sub.2), SiH.sub.2Br(N(iPr).sub.2), SiH.sub.2Br(N(iBu).sub.2), SiBr(NMe.sub.2).sub.3, SiH.sub.2I(N(Et).sub.2), SiH.sub.2I(N(iPr).sub.2), SiH.sub.2I(N(iBu).sub.2) or SiI(NMe.sub.2).sub.3.
EXAMPLES
(89) The following non-limiting examples are provided to further illustrate embodiments of the invention. However, the examples are not intended to be all inclusive and are not intended to limit the scope of the inventions described herein.
Example 1
Synthesis of diethylamino(iodo)silane SiH2I(NEt2)
(90) Synthesis Route: SiH.sub.2(NEt.sub.2).sub.2+SiH.sub.2I.sub.2.fwdarw.2SiH.sub.2I(NEt.sub.2) (Neat Reaction).
(91) Under an atmosphere of pure N.sub.2, a flask is charged with diiodosilane (SiH.sub.2I.sub.2) (41.2 g, 0.145 mol) and cooled to 0 C. Bis(diethylamino)silane (SiH.sub.2(NEt.sub.2).sub.2) (25.4 g, 0.146 mol) is chilled to 0 C. and then added at a rate of 0.5 mL/minute to the reaction flask. Fuming is observed during the course of the addition. The reaction is subsequently allowed to warm to room temperature and stirred for 4 hours to obtain a cloudy, pale yellow liquid.
(92) The crude product is then distilled over a short path column (30-32 C., 1.2 mTorr) to yield a colorless, air sensitive, free flowing liquid (57.3 g, 85% yield). The product was analyzed by GCMS which shows >99% purity. The structure of the product is confirmed by .sup.1H, .sup.13C & .sup.29Si NMR.
(93) Distilled SiH.sub.2I(NEt.sub.2) TGA is shown in
(94) The properties of SiH.sub.2I(NEt.sub.2) are as follows.
(95) Distilled SiH.sub.2I(NEt.sub.2) Vapor pressure=10 Torr @ 27 C.
(96) Isolated Yield=57.3 g (86% unoptimized).
(97) MP=<70 C.
(98) TGA residue (oc)=<1%.
(99) Thermal Test (8 hrs @ 80 C.) shows <1% decomposition.
(100) Purity (GCMS & .sup.1H NMR) >99%.
Example 2
Synthesis of diisopropylamino(iodo)silane SiH2I(NiPr2)
(101) Synthesis Route: SiH.sub.2I.sub.2+SiH.sub.2(NiPr.sub.2).sub.2.fwdarw.2SiH.sub.2I(NiPr.sub.2) (Neat Reaction)
(102) Under an atmosphere of pure N.sub.2, a flask is charged with diiodosilane (28.5 g, 0.100 mol). At 24 C., bis(diisopropylamino)silane (23.4 g, 0.101 mol) is added at a rate of 1 mL/minute and stirred for 4 hours to obtain a cloudy, pale yellow liquid.
(103) The crude product is then distilled over a short path column (25-30 C., 80-120 mTorr) to yield a colorless, air sensitive, free flowing liquid (43.2 g, 84% yield). The product was analyzed by GCMS which shows >99% purity. Structure confirmed by .sup.1H, .sup.13C & .sup.29Si NMR.
(104) Distilled SiH.sub.2I(N(iPr).sub.2) TGA is shown in
(105) The properties of SiH.sub.2I(N(iPr).sub.2) are as follows.
(106) Distilled SiH.sub.2I(N(iPr).sub.2) Vapor pressure @ 41 C. is 10 Torr.
(107) Isolated Yield is 43.2 g (84%).
(108) MP is 8 C.
(109) Appearance: colorless liquid.
(110) Purity (GCMS & .sup.1H NMR) shows >99% purity product SiH.sub.2I(N(iPr).sub.2).
(111) .sup.1H & .sup.29Si NMR confirms GCMS, shows single product SiH.sub.2I(N(iPr).sub.2).
(112) .sup.13C NMR shows expected peaks for clean product SiH.sub.2I(N(iPr).sub.2).
(113) Density @ 24 C. is 1.35 g/mL.
(114) Viscosity @ 24 C. is 1.42 cSt.
Example 3
Synthesis of dibutylamino(iodo)silane SiH2I(N(iBu)2)
(115) Synthesis Route: SiH.sub.2I.sub.2+SiH.sub.2(N(iBu).sub.2).sub.2.fwdarw.2SiH.sub.2I(N(iBu).sub.2) (Neat Reaction)
(116) Under an atmosphere of pure N.sub.2, a flask is charged with diiodosilane (15.6 g, 0.055 mol) and cooled to 0 C. Bis(dibutylamino)silane (15.8 g, 0.055 mol) is chilled to 0 C. and then added at a rate of 1 mL/minute to the reaction flask. Fuming is observed initially. The reaction is subsequently allowed to warm to room temperature and stirred for 6 hours to obtain a cloudy, pale yellow liquid.
(117) The crude product is then distilled over a short path column (33-37 C., 50-70 mTorr) to yield a colorless, air sensitive, free flowing liquid (27.6 g, 88% yield). The product was analyzed by GCMS which shows >99% purity. Structure confirmed by .sup.1H, .sup.13C & .sup.29Si NMR.
(118) Distilled SiH.sub.2I(N(iBu).sub.2) TGA is shown in
(119) The properties of SiH.sub.2I(N(iBu).sub.2) are as follows.
(120) Distilled SiH.sub.2I(N(iBu).sub.2) Vapor Pressure=1 Torr @ 29 C.
(121) Isolated Yield=27.6 g (88%) [distillation conditions: 33-37 C. @ 50-70 mTorr].
(122) MP=<70 C.
(123) TGA residue (oc) <1%.
(124) Appearance is colorless liquid.
(125) Thermal Test (8 hrs @ 80 C.) <1% decomposition.
(126) .sup.1H & .sup.29Si NMR confirms GCMS shows single product SiH.sub.2I(N(iBu).sub.2).
(127) .sup.13C NMR confirms GCMS shows single product SiH.sub.2I(N(iBu).sub.2).
(128) Purity (GCMS & .sup.1H NMR) >99%.
(129) Density=1.28 g/mL @ 24 C.
(130) Viscosity=1.79 cSt @ 24 C.
Example 4
Synthesis of bis(dimethylamino)iodosilane SiHI(NMe2)2
(131) Synthesis Route: SiHI.sub.3+SiH(NMe.sub.2).sub.3.fwdarw.2SiHI(NMe.sub.2).sub.2 (Neat Reaction)
(132) A flask containing tris(dimethylamino)silane (15.9 g, 0.099 mol) under an atmosphere of dry N.sub.2 is chilled to 0 C. and triiodosilane (20.4 g, 0.049 mol) is added at a rate of 1 mL/minute. Some fuming is observed initially. The reaction is subsequently allowed to warm to room temperature and stirred for 16 hours to obtain a slightly cloudy, pale yellow liquid. The product is distilled over a short path column (30-35 C., 80-110 mTorr) to yield a colorless, air sensitive, free flowing liquid (23.3 g, 65% yield). The product identified as bis(dimethylamino)iodosilane was analyzed by GCMS which shows >95% purity. Structure and purity were confirmed by .sup.1H & .sup.13C NMR.
(133) The TGA analysis of SiHI(NMe.sub.2).sub.2 is shown in
Example 5
Synthesis of (diisopropylamino)bromodisilane [SiH2Br(NiPr2)]
(134) Synthesis Route: SiBr.sub.4+SiH.sub.2(NiPr.sub.2).sub.2.fwdarw.SiH.sub.2Br(NiPr.sub.2)+SiBr.sub.3(NiPr.sub.2) (in CHCl.sub.3)
(135) A flask equipped with a reflux condenser and containing a chloroform (100 mL) solution of bis(diisopropylamino)silane (27.4 g, 0.119 mol) under an atmosphere of dry N.sub.2 is chilled to 0 C. and tetrabromosilane (41.8 g, 0.120 mol) is added at a rate of 1 mL/minute. The reaction is subsequently allowed to warm to room temperature and then heated with stirring for 9 hours to obtain a cloudy, colorless suspension. A sample of the reaction mixture is dissolved completely into dichloromethane (1 mL) and analyzed by GCMS which shows greater than 99% conversion to the products (diisopropylamino)bromosilane and (diisopropylamino)tribromosilane with less than 1% remaining of the starting reagent tetrabromosilane and less than 0.1% remaining of bis(diisopropylamino)silane.
Example 6
Synthesis of mono(diisopropylamino)iododisilane [H2ISiSiH2(NiPr2)]
(136) Synthesis Route: SiH.sub.2I.sub.2+(NiPr.sub.2)H.sub.2SiSiH.sub.2(NiPr.sub.2).fwdarw.SiH.sub.2I(NiPr.sub.2)+H.sub.2ISiSiH.sub.2(N.sup.iPr.sub.2)(in C.sub.5H.sub.12)
(137) Under an atmosphere of dry N.sub.2, anhydrous pentane (20.0 mL, 0.174 mol) was added to a flask containing diiodosilane (2.1 g, 7.34 mmol) and equipped with a condenser. 1,2-bis(diisopropylamino)disilane (1.9 g, 7.34 mmol) is added and the mixture heated with stirring to form a yellow solution at room temperature for 2 hours. An aliquot was taken for analysis by GCMS. The composition of the silicon containing products is observed as follows: SiI(N.sup.iPr.sub.2)H.sub.2 (70.3%), H.sub.2ISiSiH.sub.2(N.sup.iPr.sub.2), (29.7%).
(138)
Comparative Example 1
Synthesis of bis(dimethylamino)diiodosilane [SiI2(NMe2)2]
(139) Synthesis Route: SiI.sub.4+Si(NMe.sub.2).sub.4.fwdarw.Si(NMe.sub.2).sub.4, SiI(NMe.sub.2).sub.3, SiI.sub.2(NMe.sub.2).sub.2, SiI.sub.3(NMe.sub.2) and SiI.sub.4 (in Toluene)
(140) Under an atmosphere of dry N.sub.2, anhydrous toluene (30.0 mL, 0.284 mol) was added to a flask containing silicon tetraiodide (25.2 g, 0.047 mol) and equipped with a condenser. Tetrakis(dimethylamino)silane (10.4 g, 0.051 mol) is added followed by triethylamine (1.0 mL, 0.007 mol) and the mixture heated with stirring to form a yellow solution at 90 C. for 6 hours. The reaction is cooled to 23 C. and an aliquot taken for analysis by GCMS. The composition of the silicon containing products is observed as follows: Si(NMe.sub.2).sub.4 (60.1%), SiI(NMe.sub.2).sub.3, (2.2%), SiI.sub.2(NMe.sub.2).sub.2 (3.1%), SiI.sub.3(NMe.sub.2) (3.7%) and SiI.sub.4 (30.9%). In other words, the reaction between SiI.sub.4 and Si(NR.sub.2).sub.4 is not as fruitful as the reaction between SiCl.sub.4 and Si(NR.sub.2).sub.4 reported by Passarelli et al., demonstrating that the halides do not always behave similarly. Dalt. Trans., 2003, at 417.
Comparative Example 2
Synthesis of (tert-butylamino)iodosilane [SiH2I(NHtBu)]
(141) Synthesis Route: SiH.sub.2I.sub.2+SiH.sub.2(NHtBu).sub.2SiH.sub.2I(NHtBu) (Neat)
(142) Under an atmosphere of dry N.sub.2 at 23 C., bis(tert-butylamino)silane (1.72 g, 9.86 mmol) is added dropwise to a flask containing diodosilane (2.80 g, 9.86 mmol). Some fuming and the formation of colorless solids are observed. A sample of the product mixture is dissolved in dichloromethane (0.5 mL, 7.83 mmol) and analyzed by GCMS. The observed products do not include the target compound (tert-butylamino)iodosilane. Instead, the products included SiI(NHtBu).sub.3 and a cyclic [SiH.sub.2N(tBu)-].sub.3. Applicants believe that the H atom on the amino group may lead to undesired polymerized products.
(143) It will be understood that many additional changes in the details, materials, steps, and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims. Thus, the present invention is not intended to be limited to the specific embodiments in the examples given above and/or the attached drawings.