WO2019060479A1 - Cleavage of methyldisilanes to methylmonosilanes - Google Patents
Cleavage of methyldisilanes to methylmonosilanes Download PDFInfo
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- WO2019060479A1 WO2019060479A1 PCT/US2018/051851 US2018051851W WO2019060479A1 WO 2019060479 A1 WO2019060479 A1 WO 2019060479A1 US 2018051851 W US2018051851 W US 2018051851W WO 2019060479 A1 WO2019060479 A1 WO 2019060479A1
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- WIPO (PCT)
- Prior art keywords
- process according
- hci
- general formula
- sih
- ether
- Prior art date
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- 238000003776 cleavage reaction Methods 0.000 title claims abstract description 70
- UIUXUFNYAYAMOE-UHFFFAOYSA-N methylsilane Chemical class [SiH3]C UIUXUFNYAYAMOE-UHFFFAOYSA-N 0.000 title claims abstract description 54
- IQCYANORSDPPDT-UHFFFAOYSA-N methyl(silyl)silane Chemical class C[SiH2][SiH3] IQCYANORSDPPDT-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 230000007017 scission Effects 0.000 title description 35
- 238000000034 method Methods 0.000 claims abstract description 96
- 230000008569 process Effects 0.000 claims abstract description 94
- 238000004519 manufacturing process Methods 0.000 claims abstract description 13
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 claims description 138
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 claims description 121
- IXCSERBJSXMMFS-UHFFFAOYSA-N hydrogen chloride Substances Cl.Cl IXCSERBJSXMMFS-UHFFFAOYSA-N 0.000 claims description 121
- 229910000041 hydrogen chloride Inorganic materials 0.000 claims description 121
- 238000006243 chemical reaction Methods 0.000 claims description 54
- 238000005660 chlorination reaction Methods 0.000 claims description 32
- -1 ether compound Chemical class 0.000 claims description 28
- 239000003960 organic solvent Substances 0.000 claims description 26
- 239000000758 substrate Substances 0.000 claims description 26
- 239000002904 solvent Substances 0.000 claims description 24
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 claims description 19
- DURPTKYDGMDSBL-UHFFFAOYSA-N 1-butoxybutane Chemical compound CCCCOCCCC DURPTKYDGMDSBL-UHFFFAOYSA-N 0.000 claims description 19
- KQHIGRPLCKIXNJ-UHFFFAOYSA-N chloro-methyl-silylsilane Chemical class C[SiH]([SiH3])Cl KQHIGRPLCKIXNJ-UHFFFAOYSA-N 0.000 claims description 18
- YGZSVWMBUCGDCV-UHFFFAOYSA-N chloro(methyl)silane Chemical compound C[SiH2]Cl YGZSVWMBUCGDCV-UHFFFAOYSA-N 0.000 claims description 17
- 238000005984 hydrogenation reaction Methods 0.000 claims description 16
- 229910008045 Si-Si Inorganic materials 0.000 claims description 15
- 229910006411 Si—Si Inorganic materials 0.000 claims description 15
- 229920006395 saturated elastomer Polymers 0.000 claims description 13
- 229910003828 SiH3 Inorganic materials 0.000 claims description 12
- 229910052987 metal hydride Inorganic materials 0.000 claims description 10
- 150000004681 metal hydrides Chemical class 0.000 claims description 10
- BGGYXMKCQZHAAZ-UHFFFAOYSA-M cyclohexyl-[(4,4-dimethylpiperazin-4-ium-1-yl)methyl]-hydroxy-(2-methoxyphenyl)silane;methyl sulfate Chemical compound COS([O-])(=O)=O.COC1=CC=CC=C1[Si](O)(C1CCCCC1)CN1CC[N+](C)(C)CC1 BGGYXMKCQZHAAZ-UHFFFAOYSA-M 0.000 claims description 7
- 150000004678 hydrides Chemical class 0.000 claims description 7
- 239000004210 ether based solvent Substances 0.000 claims description 6
- UBHZUDXTHNMNLD-UHFFFAOYSA-N dimethylsilane Chemical compound C[SiH2]C UBHZUDXTHNMNLD-UHFFFAOYSA-N 0.000 claims description 5
- 239000012279 sodium borohydride Substances 0.000 claims description 5
- 229910000033 sodium borohydride Inorganic materials 0.000 claims description 5
- JEDZLBFUGJTJGQ-UHFFFAOYSA-N [Na].COCCO[AlH]OCCOC Chemical compound [Na].COCCO[AlH]OCCOC JEDZLBFUGJTJGQ-UHFFFAOYSA-N 0.000 claims description 3
- YGHUUVGIRWMJGE-UHFFFAOYSA-N chlorodimethylsilane Chemical compound C[SiH](C)Cl YGHUUVGIRWMJGE-UHFFFAOYSA-N 0.000 claims description 3
- 239000012419 sodium bis(2-methoxyethoxy)aluminum hydride Substances 0.000 claims description 3
- DBGVGMSCBYYSLD-UHFFFAOYSA-N tributylstannane Chemical compound CCCC[SnH](CCCC)CCCC DBGVGMSCBYYSLD-UHFFFAOYSA-N 0.000 claims description 3
- LIKFHECYJZWXFJ-UHFFFAOYSA-N dimethyldichlorosilane Chemical compound C[Si](C)(Cl)Cl LIKFHECYJZWXFJ-UHFFFAOYSA-N 0.000 claims 1
- 239000000203 mixture Substances 0.000 description 52
- PZPGRFITIJYNEJ-UHFFFAOYSA-N disilane Chemical group [SiH3][SiH3] PZPGRFITIJYNEJ-UHFFFAOYSA-N 0.000 description 36
- 239000000047 product Substances 0.000 description 34
- 150000001875 compounds Chemical class 0.000 description 33
- 239000003153 chemical reaction reagent Substances 0.000 description 32
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical class [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 27
- 229960004132 diethyl ether Drugs 0.000 description 24
- 239000000243 solution Substances 0.000 description 20
- 230000015572 biosynthetic process Effects 0.000 description 16
- 230000035484 reaction time Effects 0.000 description 15
- 239000007858 starting material Substances 0.000 description 12
- 150000002170 ethers Chemical class 0.000 description 11
- 238000004821 distillation Methods 0.000 description 10
- 238000005481 NMR spectroscopy Methods 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical group N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 8
- 229940052303 ethers for general anesthesia Drugs 0.000 description 8
- 238000003786 synthesis reaction Methods 0.000 description 8
- KOPOQZFJUQMUML-UHFFFAOYSA-N chlorosilane Chemical class Cl[SiH3] KOPOQZFJUQMUML-UHFFFAOYSA-N 0.000 description 7
- 239000000523 sample Substances 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 238000009835 boiling Methods 0.000 description 6
- 125000004435 hydrogen atom Chemical group [H]* 0.000 description 6
- 239000011541 reaction mixture Substances 0.000 description 6
- 238000000926 separation method Methods 0.000 description 6
- 239000000126 substance Substances 0.000 description 6
- 239000005046 Chlorosilane Substances 0.000 description 5
- 125000001033 ether group Chemical group 0.000 description 5
- 230000002035 prolonged effect Effects 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical group [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical group [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 4
- 238000010504 bond cleavage reaction Methods 0.000 description 4
- 230000002860 competitive effect Effects 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 4
- SBZXBUIDTXKZTM-UHFFFAOYSA-N diglyme Chemical compound COCCOCCOC SBZXBUIDTXKZTM-UHFFFAOYSA-N 0.000 description 4
- FHQRQPAFALORSL-UHFFFAOYSA-N dimethylsilyl(trimethyl)silane Chemical compound C[SiH](C)[Si](C)(C)C FHQRQPAFALORSL-UHFFFAOYSA-N 0.000 description 4
- 125000000524 functional group Chemical group 0.000 description 4
- 150000008282 halocarbons Chemical class 0.000 description 4
- 229910052757 nitrogen Inorganic materials 0.000 description 4
- 229910052760 oxygen Inorganic materials 0.000 description 4
- 239000001301 oxygen Substances 0.000 description 4
- 150000004756 silanes Chemical class 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- VIPCDVWYAADTGR-UHFFFAOYSA-N trimethyl(methylsilyl)silane Chemical compound C[SiH2][Si](C)(C)C VIPCDVWYAADTGR-UHFFFAOYSA-N 0.000 description 4
- 238000005133 29Si NMR spectroscopy Methods 0.000 description 3
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- VEXZGXHMUGYJMC-UHFFFAOYSA-M Chloride anion Chemical compound [Cl-] VEXZGXHMUGYJMC-UHFFFAOYSA-M 0.000 description 3
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 3
- RDOXTESZEPMUJZ-UHFFFAOYSA-N anisole Chemical compound COC1=CC=CC=C1 RDOXTESZEPMUJZ-UHFFFAOYSA-N 0.000 description 3
- UHOVQNZJYSORNB-MZWXYZOWSA-N benzene-d6 Chemical compound [2H]C1=C([2H])C([2H])=C([2H])C([2H])=C1[2H] UHOVQNZJYSORNB-MZWXYZOWSA-N 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 238000009833 condensation Methods 0.000 description 3
- 230000005494 condensation Effects 0.000 description 3
- 238000010494 dissociation reaction Methods 0.000 description 3
- 230000005593 dissociations Effects 0.000 description 3
- 238000001704 evaporation Methods 0.000 description 3
- 239000007789 gas Substances 0.000 description 3
- 229930195733 hydrocarbon Natural products 0.000 description 3
- 150000002430 hydrocarbons Chemical class 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 229910052751 metal Inorganic materials 0.000 description 3
- 239000002184 metal Substances 0.000 description 3
- 229910052752 metalloid Inorganic materials 0.000 description 3
- 150000002738 metalloids Chemical class 0.000 description 3
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 3
- 229920001296 polysiloxane Polymers 0.000 description 3
- 239000010909 process residue Substances 0.000 description 3
- 239000003586 protic polar solvent Substances 0.000 description 3
- 239000012047 saturated solution Substances 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- PQDJYEQOELDLCP-UHFFFAOYSA-N trimethylsilane Chemical class C[SiH](C)C PQDJYEQOELDLCP-UHFFFAOYSA-N 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- BZLVMXJERCGZMT-UHFFFAOYSA-N Methyl tert-butyl ether Chemical compound COC(C)(C)C BZLVMXJERCGZMT-UHFFFAOYSA-N 0.000 description 2
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical group [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 2
- 125000000217 alkyl group Chemical group 0.000 description 2
- 125000004429 atom Chemical class 0.000 description 2
- 230000001588 bifunctional effect Effects 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000010790 dilution Methods 0.000 description 2
- 239000012895 dilution Substances 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 238000004508 fractional distillation Methods 0.000 description 2
- 238000002290 gas chromatography-mass spectrometry Methods 0.000 description 2
- 125000005842 heteroatom Chemical group 0.000 description 2
- 238000007038 hydrochlorination reaction Methods 0.000 description 2
- 229910052739 hydrogen Inorganic materials 0.000 description 2
- 230000010354 integration Effects 0.000 description 2
- 230000011987 methylation Effects 0.000 description 2
- 238000007069 methylation reaction Methods 0.000 description 2
- 239000000178 monomer Substances 0.000 description 2
- 150000002894 organic compounds Chemical class 0.000 description 2
- 238000002360 preparation method Methods 0.000 description 2
- 230000009467 reduction Effects 0.000 description 2
- 230000002829 reductive effect Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 239000002210 silicon-based material Substances 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 125000001424 substituent group Chemical group 0.000 description 2
- 229910052717 sulfur Chemical group 0.000 description 2
- 239000011593 sulfur Chemical group 0.000 description 2
- HYDWALOBQJFOMS-UHFFFAOYSA-N 3,6,9,12,15-pentaoxaheptadecane Chemical compound CCOCCOCCOCCOCCOCC HYDWALOBQJFOMS-UHFFFAOYSA-N 0.000 description 1
- 101100515517 Arabidopsis thaliana XI-I gene Proteins 0.000 description 1
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- AQZGPSLYZOOYQP-UHFFFAOYSA-N Diisoamyl ether Chemical compound CC(C)CCOCCC(C)C AQZGPSLYZOOYQP-UHFFFAOYSA-N 0.000 description 1
- 230000005526 G1 to G0 transition Effects 0.000 description 1
- 101150055528 SPAM1 gene Proteins 0.000 description 1
- BUGBHKTXTAQXES-UHFFFAOYSA-N Selenium Chemical compound [Se] BUGBHKTXTAQXES-UHFFFAOYSA-N 0.000 description 1
- 229910007258 Si2H4 Inorganic materials 0.000 description 1
- 229910003930 SiCb Inorganic materials 0.000 description 1
- 239000002250 absorbent Substances 0.000 description 1
- 230000002745 absorbent Effects 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 238000006136 alcoholysis reaction Methods 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 239000003708 ampul Substances 0.000 description 1
- 239000012491 analyte Substances 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 229910052787 antimony Inorganic materials 0.000 description 1
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910052785 arsenic Inorganic materials 0.000 description 1
- RQNWIZPPADIBDY-UHFFFAOYSA-N arsenic atom Chemical compound [As] RQNWIZPPADIBDY-UHFFFAOYSA-N 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 125000000732 arylene group Chemical group 0.000 description 1
- 229910052789 astatine Inorganic materials 0.000 description 1
- RYXHOMYVWAEKHL-UHFFFAOYSA-N astatine atom Chemical compound [At] RYXHOMYVWAEKHL-UHFFFAOYSA-N 0.000 description 1
- 238000000998 batch distillation Methods 0.000 description 1
- 239000002981 blocking agent Substances 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910052796 boron Inorganic materials 0.000 description 1
- 239000006227 byproduct Substances 0.000 description 1
- 150000001721 carbon Chemical group 0.000 description 1
- 125000002091 cationic group Chemical group 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 239000012320 chlorinating reagent Substances 0.000 description 1
- 125000001309 chloro group Chemical group Cl* 0.000 description 1
- NEHMKBQYUWJMIP-NJFSPNSNSA-N chloro(114C)methane Chemical compound [14CH3]Cl NEHMKBQYUWJMIP-NJFSPNSNSA-N 0.000 description 1
- QABCGOSYZHCPGN-UHFFFAOYSA-N chloro(dimethyl)silicon Chemical compound C[Si](C)Cl QABCGOSYZHCPGN-UHFFFAOYSA-N 0.000 description 1
- 239000002131 composite material Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000001944 continuous distillation Methods 0.000 description 1
- 230000008878 coupling Effects 0.000 description 1
- 239000007822 coupling agent Substances 0.000 description 1
- 238000010168 coupling process Methods 0.000 description 1
- 238000005859 coupling reaction Methods 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 150000004292 cyclic ethers Chemical class 0.000 description 1
- 230000001419 dependent effect Effects 0.000 description 1
- KTQYJQFGNYHXMB-UHFFFAOYSA-N dichloro(methyl)silicon Chemical compound C[Si](Cl)Cl KTQYJQFGNYHXMB-UHFFFAOYSA-N 0.000 description 1
- JZALIDSFNICAQX-UHFFFAOYSA-N dichloro-methyl-trimethylsilylsilane Chemical compound C[Si](C)(C)[Si](C)(Cl)Cl JZALIDSFNICAQX-UHFFFAOYSA-N 0.000 description 1
- UCMVNBCLTOOHMN-UHFFFAOYSA-N dimethyl(silyl)silane Chemical compound C[SiH](C)[SiH3] UCMVNBCLTOOHMN-UHFFFAOYSA-N 0.000 description 1
- KPUWHANPEXNPJT-UHFFFAOYSA-N disiloxane Chemical compound [SiH3]O[SiH3] KPUWHANPEXNPJT-UHFFFAOYSA-N 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 230000007717 exclusion Effects 0.000 description 1
- 239000012634 fragment Substances 0.000 description 1
- 239000008246 gaseous mixture Substances 0.000 description 1
- 229910052732 germanium Inorganic materials 0.000 description 1
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 238000003919 heteronuclear multiple bond coherence Methods 0.000 description 1
- 238000005570 heteronuclear single quantum coherence Methods 0.000 description 1
- NEXSMEBSBIABKL-UHFFFAOYSA-N hexamethyldisilane Chemical compound C[Si](C)(C)[Si](C)(C)C NEXSMEBSBIABKL-UHFFFAOYSA-N 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 238000007327 hydrogenolysis reaction Methods 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 238000006459 hydrosilylation reaction Methods 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000003446 ligand Substances 0.000 description 1
- 230000000670 limiting effect Effects 0.000 description 1
- 230000014759 maintenance of location Effects 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910001507 metal halide Inorganic materials 0.000 description 1
- 150000005309 metal halides Chemical class 0.000 description 1
- 229910021645 metal ion Inorganic materials 0.000 description 1
- UZKWTJUDCOPSNM-UHFFFAOYSA-N methoxybenzene Substances CCCCOC=C UZKWTJUDCOPSNM-UHFFFAOYSA-N 0.000 description 1
- QCAWEPFNJXQPAN-UHFFFAOYSA-N methoxyfenozide Chemical compound COC1=CC=CC(C(=O)NN(C(=O)C=2C=C(C)C=C(C)C=2)C(C)(C)C)=C1C QCAWEPFNJXQPAN-UHFFFAOYSA-N 0.000 description 1
- 239000005048 methyldichlorosilane Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 238000000465 moulding Methods 0.000 description 1
- 150000004010 onium ions Chemical class 0.000 description 1
- 125000001190 organyl group Chemical group 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 230000036961 partial effect Effects 0.000 description 1
- JTJMJGYZQZDUJJ-UHFFFAOYSA-N phencyclidine Chemical class C1CCCCN1C1(C=2C=CC=CC=2)CCCCC1 JTJMJGYZQZDUJJ-UHFFFAOYSA-N 0.000 description 1
- 229910052699 polonium Inorganic materials 0.000 description 1
- HZEBHPIOVYHPMT-UHFFFAOYSA-N polonium atom Chemical compound [Po] HZEBHPIOVYHPMT-UHFFFAOYSA-N 0.000 description 1
- 238000000425 proton nuclear magnetic resonance spectrum Methods 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 238000009877 rendering Methods 0.000 description 1
- 239000013557 residual solvent Substances 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 230000000717 retained effect Effects 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000000565 sealant Substances 0.000 description 1
- 229910052711 selenium Inorganic materials 0.000 description 1
- 239000011669 selenium Substances 0.000 description 1
- 238000000526 short-path distillation Methods 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 229910021332 silicide Inorganic materials 0.000 description 1
- 238000001577 simple distillation Methods 0.000 description 1
- 238000004611 spectroscopical analysis Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 125000005156 substituted alkylene group Chemical group 0.000 description 1
- 238000006467 substitution reaction Methods 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- 229910052714 tellurium Inorganic materials 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
- 150000003512 tertiary amines Chemical class 0.000 description 1
- 238000004448 titration Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
- 238000005292 vacuum distillation Methods 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
- 238000005303 weighing Methods 0.000 description 1
- 238000010626 work up procedure Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
- C07F7/02—Silicon compounds
- C07F7/08—Compounds having one or more C—Si linkages
- C07F7/0803—Compounds with Si-C or Si-Si linkages
- C07F7/0825—Preparations of compounds not comprising Si-Si or Si-cyano linkages
- C07F7/083—Syntheses without formation of a Si-C bond
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
- C07F7/02—Silicon compounds
- C07F7/08—Compounds having one or more C—Si linkages
- C07F7/12—Organo silicon halides
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
- C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
- C07F7/02—Silicon compounds
- C07F7/08—Compounds having one or more C—Si linkages
- C07F7/12—Organo silicon halides
- C07F7/121—Preparation or treatment not provided for in C07F7/14, C07F7/16 or C07F7/20
- C07F7/123—Preparation or treatment not provided for in C07F7/14, C07F7/16 or C07F7/20 by reactions involving the formation of Si-halogen linkages
Definitions
- the present invention relates to the technical field of the production of methylmonosilanes, in particular to the production of mono-, di- and trimethylmonosilanes, more specifically to a process for the production of mono-, di- and trimethylmonosilanes starting from methyldisilanes by a cleavage reaction of the silicon-silicon bond.
- Methylchlorosilanes and methylhydridosilanes are highly useful starting materials in synthetic organosilicon chemistry, and therefore constitute an industrially valuable class of compounds.
- methylsilanes bearing both chloro- and hydrido substituents constitute attractive starting materials in synthesis due to their bifunctional nature, which means they have functional groups of different reactivities.
- the chloride ligand is a better leaving group than the hydride group and allows, for instance, the controlled addition of further monomeric or oligomeric siloxane units with retention of the Si-H bond under mild conditions, thereby rendering said chlorohydridosilanes useful as blocking and coupling agents in the synthesis of defined oligo- and polysiloxanes.
- Such compounds generally find a wide range of applications, for instance for the manufacture of adhesives, sealants, mouldings, composites and resins for example in the fields of electronics, automotive, construction and many more.
- Si-H moieties present in chlorosilanes can be utilized for post-synthesis modifications and functionalisations, for instance for the introduction of organic residues to polyorganosiloxanes or for cross-linking by hydrosilylation reactions, which is desirable in various kinds of compositions containing polyorganosiloxanes.
- Synthesis of functionalized polysiloxanes starting with transformations via the Si-H bond(s) followed by hydrolysis or alcoholysis of the Si-CI bond(s) and optionally condensation for the formation of polysiloxanes is also viable.
- US 5 288 892 describes a process for separating methylchlorosilanes from high boiling residues from the methylchlorosilane synthesis.
- DD 274 227 concerns a process for the production of chlor-methyl-silanes from chlor-methyl- disilanes.
- the problem to be solved by the present invention is the provision of a process for the production of, in particular, methylchloro- and methylhydridomonosilanes from methyldisilanes by Si-Si-bond cleavage, wherein the methylhydridodisilanes can be preferably obtained by hydrogenation of methylchlorodisilanes from the Rochow Mtiller disilane residue.
- the invention in particular addresses the provision of such an improved process in which high proportions of methylhydridomonosilanes can be obtained. According to the present invention this problem is solved as described in the following .
- the present invention relates to a process for the production of methylmonosilanes starting from the corresponding methyldisilanes by cleavage of the silicon-silicon bond.
- Subject of the invention is a process for the manufacture of methylmonosilanes of the general formula (I):
- step A) optionally a step of separating the resulting methylmonosilanes of the formula (I), wherein step A) is carried out by subjecting the methylhydndodisilanes of the general formula (II) to the reaction with hydrogen chloride (HCI) in the presence of one or more aprotic organic solvents.
- HCI hydrogen chloride
- protic organic solvents are usually solvents that do not have a functional group from which hydrogen atoms can be split off as protons (dissociation) under the process conditions as opposed to the protic solvents).
- Formula (II) MenSi 2 H6-n can be depicted e.g. by a structural formula:
- R' R' wherein the R' substituents can be independently selected from methyl (Me) and hydrogen (H), with the proviso that there are 1 to 5 methyl substituents.
- cleavage is the term used to describe the process whereby disilanes are reacted to produce monomeric silanes.
- the term "cleavage reaction of the silicon-silicon bond” further indicates that according to the invention, the cleavage of the disilanes of the general formula (II) is effected by breaking the bond connecting the silicon atoms of the disilanes.
- Such cleavage processes include in particular hydrochlorination and hydrogenolysis.
- one compound of general formula (I) or a mixture of more than one compound of general formula (I) is formed. More preferably, mixtures of more than one compound of the formula (I) are formed.
- the methylmonosilanes of the general formula (I) formed in the process of the present invention include compounds selected from the group of: MeSihbCI, Me2SiH2, Me 2 SiHCI, Me 3 SiH, Me 3 SiCI, MeSiHC , Me 2 SiCI 2 and MeSiH 3 .
- the methylmonosilanes of the general formula (I) formed in the process according to the invention include compounds selected from the group of Me2SiH2, Me 2 SiHCI and MeSiH 2 CI.
- Preferred starting materials of the general formula (II) include one or more of the compounds selected from MehbSi-SihbMe, Me 2 HSi-SiH2Me, Me 2 HSi-SiHMe2, Me 3 Si-SiHMe2, Me 3 Si- SiH 2 Me, MeH 2 Si-SiH 3 , Me 2 HSi-SiH 3 and mixtures thereof.
- Particularly preferred starting materials of the general formula (II) comprise one or more of the compounds selected from MehbSi-SihbMe, Me2HSi-SiH2Me, Me2HSi-SiHMe2 and mixtures thereof.
- the present invention includes also the process wherein a substrate is reacted which comprises one or more methyldisilanes of the general formula (II), optionally in a mixture with other silanes not covered by general formula (I I) .
- the optional step of separating the resulting methylmonosilanes of the general formula (I) refers to any technical means applied to raise the content of one or several methylmonosilanes according to the general formula (I) in a product mixture, or which results in the separation of single compounds of the formula (I) from a product mixture obtained in step A) of the process according to the invention.
- step A) i.e. subjecting one or more methyldisilanes of the general formula (I I) to the cleavage reaction of the silicon- silicon bond
- step A is carried out by subjecting the methyldisilanes of the general formula (I I) to the reaction with hydrogen chloride (HCI) in the presence of an organic solvent, which is able to absorb or dissolve HCI and is able to cleave the Si-Si bond in the methyldisilanes in the presence of HCI.
- HCI hydrogen chloride
- aprotic organic solvents are usually solvents that do not have a functional group from which hydrogen atoms can be split off as protons (dissociation) under the process conditions as opposed to the protic solvents.
- An aprotic organic solvent is any organic compound which is in liquid state at room temperature (about 23°C), and which is suitable as a medium for conducting the cleavage reactions therein. Accordingly, the aprotic organic solvent is preferably inert to hydrogen chloride under reaction conditions.
- the starting materials of the general formula (I I) and the products of the general formula (I) are preferably soluble in the organic solvent or fully miscible, respectively.
- the term of "absorbing” or “absorption”, each respectively, refers to the process of one material (absorbate), in this case hydrogen chloride, being retained by another (absorbent) , in this case the ether compound.
- the term of dissolving or dissolution refers to the mixing of two phases with the formation of one new homogeneous phase, which in this case is a solution of hydrogen chloride in the ether compound.
- the aprotic organic solvent which is present when step A) is carried out, is selected from one or more ether solvents.
- ether solvent shall mean any organic compound containing an ether group -0-, in particular, of formula R 1 -O-R 2 , wherein Ri and R 2 are independently selected from a monovalent organyl group, which is bonded to oxygen via a carbon atom.
- Ri and R 2 are substituted or unsubstituted linear or branched alkyl groups or aryl groups, which may have further heteroatoms such as oxygen, nitrogen, or sulfur.
- Ri and R2 can constitute together an optionally substituted alkylene or arylene group, which may have further heteroatoms such as oxygen, nitrogen, or sulfur.
- the ether compounds can be symmetrical or asymmetrical with respect to the substituents at the ether group -0-.
- the ether solvents according to the invention are selected from the group consisting of linear and cyclic ether compounds.
- a cyclic ether compound according to the invention is a compound in which one or more ether groups are included in a ring formed by a series of atoms, such as for instance 1 ,4- dioxane, which can be substituted e.g. by alkyl groups.
- the ether compound is selected from the group consisting of diethyl ether, di-n-butyl ether, dioxane, preferably diethyl ether and di-n-butyl ether.
- the ether compound is selected from 1 ,4-dioxane, diethyl ether or di-n-butyl ether.
- step A) is carried out with an ether solvent containing HCI in saturated and diluted solutions.
- saturated refers to a saturated solution of hydrogen chloride in the ether compound applied, and is defined as a solution which has the same concentration of a solute as one that is in equilibrium with undissolved solute at specified values of the temperature and pressure.
- a solution being close to the state of saturation is also comprised by the term "saturated”.
- saturated solution can be prepared by passing gaseous hydrogen chloride into the corresponding ether compound (e.g. diethyl ether, di-n-butyl ether) at about 5 to about 10°C. The ether is saturated when excess HCI gas is evaporated over the overpressure valve as fast as it is introduced into the solvent.
- Diluted solutions are prepared stopping HCI- introduction into ethers before saturation or by dilution of saturated ether/HCI solutions with the corresponding pure ether solvent.
- the HCI content of the ether solvent in the reaction step A) is > about 0.1 mol/l, more preferred > about 1.0 mol/l, even more preferred > about 3 mol/l, and most preferably the ether solvent is saturated with HCI as defined above.
- the HCI content of the ether solvent is > about 1 mol/l, even more preferred about 2 mol/l, and most preferably ⁇ about 3 mol/l, that is, in a preferred embodiment, the HCI content of the ether solvent is not "saturated".
- Et 2 0 used as solvent containing HCI as HCI/diethyl ether reagent
- di-n-butyl ether used as solvent containing HCI as HCI/di-n-butyl ether reagent
- 1 ,4-dioxane used as solvent containing HCI as HCI/1 ,4-dioxane reagent.
- step A) is carried out with diethyl ether saturated with HCI serving as the ether solvent saturated with HCI.
- the saturation of the diethyl ether with hydrogen chloride is performed as described above, by passing gaseous hydrogen chloride into diethyl ether.
- a chlorination of methylhydridomonosilanes takes place during or after the cleavage reaction.
- chlorination refers to the replacement of one, two or three, preferably one or two Si-H bonds by Si-CI bonds.
- the methylhydridomonosilanes which are chlorinated during or after the cleavage reaction are methylmonosilanes of the general formula (I), wherein y is at least 1 , preferably 2 or 3.
- methylmonochlorohydridomonosilanes which are methylmonosilanes of the general formula (I), wherein z is 1 or 2, are formed.
- MeSiH 3 is chlorinated to MeSiH 2 CI
- MeSiH 3 is dichlorinated to MeSiHC
- Me 2 SiH 2 is chlorinated to Me 2 SiHCI
- Me 3 SiH is chlorinated to Me 3 SiCI.
- step A) is conducted at a temperature of about 0 °C to about 140 °C, preferably about 20 to about 120 °C, more preferably about 60 °C to about 100 °C.
- the reaction temperature in step A) according to the invention is the temperature of the reaction mixture, i.e. the temperature measured inside the reaction vessel in which the reaction is conducted.
- the reaction vessel can be an ampoule, a sealed tube, a flask or any kind of chemical reactor, without being limited thereto.
- the step A) is conducted at a pressure of about 1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
- the indicated pressure ranges refer to the pressure measured inside the reaction vessel used when conducting reaction step A).
- the molar ratio of the hydrogen chloride to the methylhydridodisilanes of the general formula (II) is at least about 1 :1 , more preferably in the range of about 1 : 1 to about 4:1.
- n HCI added to the mixture of reaction step A
- n methylhydridodisilanes of the general formula (II)
- the weight ratio of the methylhydridodisilanes of the general formula (II) to the organic solvent is less than about 1 :2, preferably in the range of about 1 :2 to about 1 :20.
- the weight ratio is defined as m (methylhydridodisilanes of the general formula (II) ) / m (organic solvent).
- the weight ratio of the hydrogen chloride to the organic solvent is less than about 1 :5, preferably in the range of about 1 :5 to about 1 :30.
- the weight ratio is defined as m (hydrogen chloride) / m (organic solvent).
- the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSihbCI, MeSiHC , Me 3 SiCI, Me 3 SiH, MeSih , Me 2 SiCI 2 and Me 2 SiH 2 and mixtures thereof.
- the methylmonosilanes of the formula (I) are selected from the group consisting of Me 2 SiHCI, MeSiH 2 CI, MeSiHCb, Me 2 SiH 2 and MeSiH3 and mixtures thereof.
- dimethylmonosilane Me 2 SiH 2 is formed by submitting a substrate selected from the group consisting of Me 2 HSi-SiHMe 2 , Me 2 HSi-SiH 2 Me, Me 2 HSi-SiH 3 or Me 2 HSi-SiMe 3 to the cleavage reaction of the Si-Si bond.
- each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II).
- methylmonosilane MeSiH3 is formed by submitting a substrate selected from the group consisting of MeH 2 Si-SiH 2 Me, MeH 2 Si-SiHMe 2 , MeH 2 Si-SiMe 3 or MeH 2 Si-SiH 3 to the cleavage reaction of the Si-Si bond.
- each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II).
- dimethylchloromonosilane Me 2 SiHCI is formed by submitting a substrate selected from the group consisting of Me 2 HSi-SiHMe 2 , Me 2 HSi-SiH 2 Me, Me 2 HSi-SiH 3 or Me 2 HSi-SiMe 3 to the cleavage reaction of the Si-Si bond.
- a substrate selected from the group consisting of Me 2 HSi-SiHMe 2 , Me 2 HSi-SiH 2 Me, Me 2 HSi-SiH 3 or Me 2 HSi-SiMe 3
- each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II).
- methylchloromonosilane MeSiH 2 CI is formed by submitting a substrate selected from the group consisting of MehbSi-SihbMe, MeH 2 Si-SiHMe2, MehbSi-Sih or MeH 2 Si-SiMe3 to the cleavage reaction of the Si-Si bond.
- each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II).
- the step of separating the resulting methylmonosilanes of the formula (I) is carried out by distillation.
- distillation in the sense of the present invention relates to any process for separating components or substances from a liquid mixture by selective evaporation and condensation. Therein, distillation may result in practically complete separation, leading to the isolation of nearly pure components, or it may be a partial separation that increases the concentration of selected components of the mixture.
- the distillation processes which may constitute separation step B), can be simple distillation, fractional distillation, vacuum distillation, short path distillation or any other kind of distillation known to the skilled person.
- the step B) of separating the chlorosilanes of the formula (I) according to the invention can comprise one or more batch distillation steps, or can comprise a continuous distillation process.
- the methylhydridodisilanes of the general formula (II) are obtained by hydrogenation of the corresponding methylchlorodisilanes of the general formula (III)
- methylchlorodisilanes are preferably residues from the Rochow-Muller Direct Process, and preferably contain mixtures of methylchlorodisilanes of formula (III).
- the term “hydrogenation” is understood as substitution of one or more chloro substituents on the silicon atoms of the methylchlorodisilanes of the general formula (III) by one or more hydrogen atoms.
- hydrogenation refers to the transformation of one or more Si-CI bonds to one or more Si-H bonds.
- the starting material of the hydrogenation step of the general formula (I II) comprises one or more of the compounds selected from MeCI 2 Si-SiCI 2 Me, Me 2 CISi- SiC Me, Me 2 CISi-SiCIMe 2 , Me 3 Si-SiCIMe 2 , Me 3 Si-SiCI 2 Me, MeC Si-SiC , Me 2 CISi-SiCI 3 and mixtures thereof.
- Particularly preferred starting materials of the general formula (III) comprise one or more of the compounds selected from MeCI 2 Si-SiCI 2 Me, Me 2 CISi-SiCI 2 Me, Me 2 CISi-SiCIMe 2 and mixtures thereof.
- the present invention includes also the case where substrates are subjected to hydrogenation which comprise one or more methylchlorodisilanes of the general formula (III) in admixture with other silanes not covered by general formula (I II).
- hydrogenation is carried out with a hydride donor, selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH 4 , n-Bu 3 SnH, NaBH 4 , (; ' -Bu 2 AIH) 2 or sodium bis(2- methoxyethoxy)aluminumhydride, which is commercially available under the trademarks Vitride® or Red-AI®, for instance.
- a hydride donor selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH 4 , n-Bu 3 SnH, NaBH 4 , (; ' -Bu 2 AIH) 2 or sodium bis(2- methoxyethoxy)aluminumhydride, which is commercially available under the trademarks Vitride® or Red-AI®, for instance.
- a hydride donor is any compound being capable of providing hydride anions for the transformation of methylchlorodisilanes of the formula (III) to methylhydridodisilanes of the formula (II).
- metal hydride refers to any hydride donor containing at least one metal atom or metal ion.
- complex metal hydrides refers to metal salts wherein the anions contain hydrides.
- complex metal hydrides contain more than one type of metal or metalloid.
- metalloid comprises the elements boron, silicon, germanium, arsenic, antimony, tellurium, carbon, aluminum, selenium, polonium, and astatine.
- the methylchlorodisilanes of the general formula (III) which are subjected to hydrogenation are residues of the Rochow-Muller Direct Process (DPR).
- DPR Rochow-Muller Direct Process
- the primary commercial method to prepare alkylhalosilanes and arylhalosilanes is through the Rochow-Muller Direct Process (also called Direct Synthesis or Direct Reaction), in which copper-activated silicon is reacted with the corresponding organohalide, in particular methyl chloride, in a gas-solid or slurry-phase reactor. Gaseous products and unreacted organohalide, along with fine particulates, are continuously removed from the reactor.
- Hot effluent exiting from the reactor comprises a mixture of copper, metal halides, silicon, silicides, carbon, gaseous organohalide, organohalosilanes, organohalodisilanes, carbosilanes and hydrocarbons.
- this mixture is first subjected to gas-solid separation in cyclones and filters. Then the gaseous mixture and ultrafine solids are condensed in a settler or slurry tank from which the organohalide, organohalosilanes, hydrocarbons and a portion of organohalodisilanes and carbosilanes are evaporated and sent to fractional distillation to recover the organohalosilane monomers.
- DPR Direct Process Residue
- methylchlorodisilanes of the general formula (I II) which are obtained as a constituent of the side-products of the Rochow-Muller Direct Process (DPR) can be transformed in particular to methylhydridosilanes of the general formula (I) via hydrogenation to methylhydridodisilanes of the general formula (II) and subsequent cleavage of the silicon-silicon bond as described.
- DPR Rochow-Muller Direct Process
- the Direct Process Residue (DPR) utilized as starting material may comprise further silicon-based compounds which do not fall under general formula (III).
- the process according to the invention is performed under inert conditions.
- the term "performed under inert conditions" means that the process is partially or completely carried out under the exclusion of surrounding air, in particular of moisture and oxygen.
- surrounding air in particular of moisture and oxygen.
- closed reaction vessels, reduced pressure and/or inert gases, in particular nitrogen or argon, or combinations of such means may be used.
- n 1 to 6, preferably 1 to 5,
- step B) optionally a step of separating the resulting methylmonosilanes of the formula (I) , wherein step A) is carried out by subjecting the methylhydndodisilanes of the general formula (II) to the reaction with hydrogen chloride (HCI) in the presence of one or more aprotic organic solvents.
- HCI hydrogen chloride
- Aprotic organic solvents are usually solvents that do not have a functional group from which hydrogen atoms can be split off as protons (dissociation) under the process conditions as opposed to the protic solvents).
- ether compound is selected from the group consisting of diethyl ether, di-n-butyl ether, dioxane, preferably diethyl ether and din-butyl ether.
- step A) is carried out with an ether solvent unsaturated or saturated with HCI, preferably an ether solvent saturated with HCI, preferably the ether solvent is diethylether.
- step A) is carried out with diethyl ether/HCI solutions of molarities in the range of about 0.5 to about 10 mol/L, preferably 1 to 6 mol/L (the solutions may have a temperature in the range of 0 to 25 °C).
- step A) is conducted at a temperature of about 0 °C to about 140 °C, preferably about 20 to about 120
- step A) is conducted at a pressure of about 1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
- step A) wherein in the step A) the molar ratio of the hydrogen chloride to the methylhydridodisilanes of the general formula (II) is at least about 1 : 1 , more preferably in the range of about 1 : 1 to about 4: 1 .
- step A) wherein in the step A) the weight ratio of the methylhydridodisilanes of the general formula (II) to the organic solvent is less than about 1 :2, preferably in the range of about 1 :2 to about 1 :20.
- step A) wherein in the step A) the weight ratio of the hydrogen chloride to the aprotic organic solvent is less than about 1 :5, preferably in the range of about 1 :5 to about 1 :30.
- methylmonosilanes of the formula (I) are selected from the group consisting of Me 2 SiHCI, MeSiH 2 CI, MeSiHCb, Me 2 SiH 2 and MeSiH 3 .
- dimethylmonosilane Me 2 SiH 2 is formed by submitting a substrate selected from the group consisting of Me 2 HSi-SiHMe 2 , Me 2 HSi-SiH 2 Me, Me 2 HSi-SiH 3 or Me 2 HSi-SiMe 3 to the cleavage reaction of the Si-Si bond.
- methylmonosilane MeSiH 3 is formed by submitting a substrate selected from the group consisting of MeH 2 Si-SiH 2 Me, MeH 2 Si-SiHMe2, MeH 2 Si-SiMe 3 or MeH 2 Si-SiH 3 to the cleavage reaction of the Si-Si bond.
- dimethylchloromonosilane Me 2 SiHCI is formed by submitting a substrate selected from the group consisting of Me 2 HSi-SiHMe 2 , Me 2 HSi-SiH 2 Me, Me 2 HSi-SiH 3 or Me 2 HSi-SiMe 3 to the cleavage reaction of the Si-Si bond.
- methylchloromonosilane MeSiH 2 CI is formed by submitting a substrate selected from the group consisting of MeH 2 Si-SiH 2 Me, MeH 2 Si-SiHMe 2 , MeH 2 Si-SiH 3 or MeH 2 Si-SiMe 3 to the cleavage reaction of the Si-Si bond.
- n is as defined above.
- compositions comprising at least one methylmonosilane of the general formula (I) as defined above, as obtainable by the process according to any of the previous embodiments.
- conventional hydrogenating reagents such as complex metal hydrides (LiAIH 4 , NaBH 4 , ((/-Bu 2 AIH)2 etc.) or mixtures thereof in ethers as solvents (e.g. diethyl ether, di-n-butyl ether, diglyme, 1 ,4-dioxan
- the complex reaction mixtures were analyzed by NMR- spectroscopy.
- the molar ratios of products formed were determined by integration of relevant NMR signals, which are assigned to specific products within the mixture.
- the amount of products formed can be estimated by the molar ratios as measured by NMR spectroscopy and the amount of starting material applied (0.1 ml), assuming a density of 1 g/cm 3 of the starting materials.
- the molarity of the HCI/ether reagent was determined by weighing the solutions: The obtained concentrations for saturated solutions were about 6 mol/l for HCI in di-n-butyl ether and about 5 mol/l for HCI in diethyl ether, and about 8-14 mol/l in 1 ,4-dioxane, depending on the amount of HCI introduced. The molarities of the HCI/ether solutions weighed were additionally confirmed by titration of HCI against sodium hydroxide (NaOH).
- di-n-butyl ether decelerates cleavage and chlorination reaction compared to diethyl ether ( ⁇ 5 mol/l HCI each):
- diethyl ether ⁇ 5 mol/l HCI each
- cleavage/chlorination reactions have to be performed under strictly comparable conditions (HCI concentration and reaction temperature control)! Reaction times are given in the tables for complete consumption of disilanes and/or hydrogen chloride.
- the stationary phase (Machery-Nagel PERMABOND Silane) had a length of 50 m with an inner diameter of 0.32 mm. 1 ⁇ of analyte solution was injected, 1/25 thereof was transferred onto the column with a flow rate of 1 .7 mL/min carried by Helium gas. The temperature of the column was first kept at 50 °C for 10 minutes. Temperature was then elevated at a rate of 20 °C/min up to 250 °C and held at that temperature for another 40 minutes. After exiting the column, substances were ionized with 70 eV and cationic fragments were measured within a range of 34 - 600 m/z (mass per charge). Product mixtures were diluted with benzene prior to the measurement. The characteristic 29 Si-NMR chemical shifts and coupling constants J ⁇ 29 Si- 1 H ⁇ for compounds I to XXII are listed in Table 1.
- LiAIH 4 (10% molar excess) was placed in a three neck flask and ether was added as solvent. Diethyl ether was used for high boiling methylhydridodisilanes of the general formula (II) and di-n-butyl ether, 1 ,4-dioxane or diglyme for low boiling disilanes of the general formula (II) to facilitate product separation by distillation at normal or reduced pressure. After cooling the ether/LiAIH 4 suspension to temperatures between -40 and 0 °C the methylchlorodisilane of the general formula (III) or a mixture comprising more than one methylchlorodisilane of the general formula (III) were added dropwise and slowly by a dropping funnel.
- 0.1 ml of a methylhydridodisilane of the general formula (II) or a mixture comprising more than one methylhydridodisilanes of the general formula (II) were dissolved in 0.1 ml C 6 D 6 and placed in an NMR tube. After cooling to -196 °C (liquid nitrogen), 0.4 ml to 0.6 ml HCI/ether reagent were added, cooled (-196 °C), evacuated in vacuo and sealed. The cleavage reactions were performed in sealed NMR tubes to prevent evaporation of low boiling products and to control the cleavage reaction proceeding at different temperatures. After warming the sample to r.t. it was measured by NMR-spectroscopy and then reacted at different temperatures to control and quantify product formation (e.g. by integration of the intensity of relevant 29 Si-NMR signals within the product mixture).
- Disilane V is nearly completely cleaved at 80 °C forming monosilanes IX and X. Obviously the cleavage product Me 2 SiH 2 (VIII) is mostly chlorinated to give chlorosilane IX.
- Methylhydridodisilane III (0.08 ml, containing 3 ⁇ diglyme) was separately reacted with the HCI/Et20 reagent ( ⁇ 5 molar, 0.5 ml) and the HCI/1 ,4-dioxane reagent (12 molar, 0.4 ml) for 18 h at 60 °C.
- Tetramethyldisilane III was completely cleaved with HCI/Et 2 0 in the presence of a small amount of diglyme in the solution.
- HCI/1 ,4-dioxane both cleaves and substitutes the SiH- SiH-moiety.
- double chlorination to give MeSiHCh requires high HCI concentrations as well as high reaction temperatures.
- the highest rate of disilane cleavage was obtained at 100 °C/5 d with a 2.5M HCI/n-Bu 2 0 solution to give 54% of MeSiH 2 CI and MeSiHCb (16.7%), while MeSiHs was detected in 7%. This is obviously due to the competitive Si-H - Si-CI chlorination of the monosilanes formed by predominant disilane cleavage.
- Disilane cleavage started at 40 ' C, the chloride of HCI binding to the Me 2 SiH-moiety, while the hydrogen atom binds to the Me 3 Si-unit.
- the molar ratio Me 2 SiHCI/Me 3 SiH is nearly 1/1 ( ⁇ 42% each), cleavage was completed to give monosilanes quantitatively.
- disilane cleavage with 2.5M HCI//7-BU2O is quantitative within 4 days at 100 C to give the expected monosilanes. While the molar ratio is about 1/1 after 1 and 2 days, longer reaction times initiate chlorination of Me 3 SiH - Me 3 SiCI with excess HCI in the sample.
- entries a) and b) As can be seen from entries a) and b) , increasing reaction temperatures supported disilane chlorination, the molar amount of monosilanes decreased from 74% to 36.5% with increasing T from 80 °C to 140 °C having the same HCI concentrations. Comparison of entries a) and c) show that an increase of the HCI concentration from 2.5M to 5.5M in 1 ,4-dioxane diminishes the amount of monosilanes from 74% to 61 %, formed at 80 °C.
- Example 18 A mixture of the highly methylated disilanes CIMe 2 Si-SiMe 2 CI (50%) , Me 3 Si-SiMe 2 CI (25%) and Me3Si-SiMe3 (25%) were mixed and reacted in n-Bu 2 0 with LiH to give per hydrogenated methyldisilanes listed in Table 19.
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Abstract
The invention relates to a process for the manufacture of methylmonosilanes comprising the step of subjecting one or more methyldisilanes to the cleavage reaction of the silicon-silicon bond, and optionally a step of separating the resulting methylmonosilanes.
Description
Cleavage of Methyldisilanes to Methylmonosilanes TECHNICAL FIELD
The present invention relates to the technical field of the production of methylmonosilanes, in particular to the production of mono-, di- and trimethylmonosilanes, more specifically to a process for the production of mono-, di- and trimethylmonosilanes starting from methyldisilanes by a cleavage reaction of the silicon-silicon bond. BACKGROUND OF THE INVENTION
Methylchlorosilanes and methylhydridosilanes are highly useful starting materials in synthetic organosilicon chemistry, and therefore constitute an industrially valuable class of compounds. I n particular, methylsilanes bearing both chloro- and hydrido substituents constitute attractive starting materials in synthesis due to their bifunctional nature, which means they have functional groups of different reactivities. The chloride ligand is a better leaving group than the hydride group and allows, for instance, the controlled addition of further monomeric or oligomeric siloxane units with retention of the Si-H bond under mild conditions, thereby rendering said chlorohydridosilanes useful as blocking and coupling agents in the synthesis of defined oligo- and polysiloxanes.
Such compounds generally find a wide range of applications, for instance for the manufacture of adhesives, sealants, mouldings, composites and resins for example in the fields of electronics, automotive, construction and many more.
The Si-H moieties present in chlorosilanes can be utilized for post-synthesis modifications and functionalisations, for instance for the introduction of organic residues to polyorganosiloxanes or for cross-linking by hydrosilylation reactions, which is desirable in various kinds of compositions containing polyorganosiloxanes.
Synthesis of functionalized polysiloxanes starting with transformations via the Si-H bond(s) followed by hydrolysis or alcoholysis of the Si-CI bond(s) and optionally condensation for the formation of polysiloxanes is also viable.
Although there is a high demand for such bifunctional silanes having both Si-H and Si-CI bonds, there is no practical, economically reasonable and sustainable industrial process for the synthesis of such building blocks disclosed yet.
The production of methylsilanes by Si-Si-bond cleavage of disilanes has been reported by Lewis and Neely in WO 2013/101618 A1 (US 8,697,901 B2) and WO 2013/101619 A1 (US 8,637,695 B2) . In these publications, the hydrochlorinative cleavage of the disilanes of the Direct Process Residue (DPR) requires the presence of heterocyclic amines or group 15 quarternary onium compounds serving as catalysts. The scope of starting materials in above- cited publications is restricted to perchlorinated methyl disilanes.
In EP 0574912 B1 (B. Pachaly, A. Schinabeck; 1993) a process for the preparation of methylchlorosilanes from the high-boiling residue from the Direct Process by Si-Si-bond cleavage with hydrogen chloride and a catalyst which remains in the reaction mixture, usually a tertiary amine, is described.
In US 4,291 , 167, Allain and Maniscalco disclose a process for the reduction of tetramethyldichlorodisilane (CIMe2Si-SiMe2CI) to tetramethyldisilane (HMe2Si-SiMe2H) with mixtures of NaH and NaBH4 in tetraethylene glycol diethyl ether.
US 5 288 892 describes a process for separating methylchlorosilanes from high boiling residues from the methylchlorosilane synthesis.
DD 274 227 concerns a process for the production of chlor-methyl-silanes from chlor-methyl- disilanes.
PROBLEM TO BE SOLVED
The problem to be solved by the present invention is the provision of a process for the production of, in particular, methylchloro- and methylhydridomonosilanes from methyldisilanes by Si-Si-bond cleavage, wherein the methylhydridodisilanes can be preferably obtained by hydrogenation of methylchlorodisilanes from the Rochow Mtiller disilane residue. Further, it is the object of present invention to provide a process with improved product yields, product purity, product selectivity of the conversion, convenience of the work-up procedure, ease of handling of the reagents and cost efficiency of the process. The invention in particular addresses the provision of such an improved process in which high proportions of methylhydridomonosilanes can be obtained. According to the present invention this problem is solved as described in the following .
DETAILED DESCRIPTION OF THE INVENTION
The present invention relates to a process for the production of methylmonosilanes starting from the corresponding methyldisilanes by cleavage of the silicon-silicon bond.
Subject of the invention is a process for the manufacture of methylmonosilanes of the general formula (I):
MexSiHyClz (I), wherein
x = 1 to 3,
y = O to 3,
z = O to 2 and
x + y + z = 4,
comprising:
A) the step of subjecting one or more methylhydndodisilanes of the general formula (II) MenSi2H6-n (II)
wherein n = 1 to 6, preferably n = 1 to 5,
to the cleavage reaction of the silicon-silicon bond, and
B) optionally a step of separating the resulting methylmonosilanes of the formula (I), wherein step A) is carried out by subjecting the methylhydndodisilanes of the general formula (II) to the reaction with hydrogen chloride (HCI) in the presence of one or more aprotic organic solvents.
(Aprotic organic solvents are usually solvents that do not have a functional group from which hydrogen atoms can be split off as protons (dissociation) under the process conditions as opposed to the protic solvents). Formula (II) MenSi2H6-n can be depicted e.g. by a structural formula:
R' R'
\ /
R'— Si— Si— R'
/ \
R' R' wherein the R' substituents can be independently selected from methyl (Me) and hydrogen (H), with the proviso that there are 1 to 5 methyl substituents. Therein, "cleavage" is the term used to describe the process whereby disilanes are reacted to produce monomeric silanes. The term "cleavage reaction of the silicon-silicon bond" further indicates that according to the invention, the cleavage of the disilanes of the general
formula (II) is effected by breaking the bond connecting the silicon atoms of the disilanes. Such cleavage processes include in particular hydrochlorination and hydrogenolysis.
It will be understood that any numerical range recited herein includes all sub-ranges within that range and any combination of the various endpoints of such ranges or sub-ranges, be it described in the examples or anywhere else in the specification.
It will also be understood herein that any of the components of the invention herein as they are described by any specific genus or species detailed in the examples section of the specification, can be used in one embodiment to define an alternative respective definition of any endpoint of a range elsewhere described in the specification with regard to that component, and can thus, in one non-limiting embodiment, be used to supplant such a range endpoint, elsewhere described. It will be further understood that any compound, material or substance which is expressly or implicitly disclosed in the specification and/or recited in a claim as belonging to a group of structurally, compositionally and/or functionally related compounds, materials or substances includes individual representatives of the group and all combinations thereof.
In the process of the present invention one compound of general formula (I) or a mixture of more than one compound of general formula (I) is formed. More preferably, mixtures of more than one compound of the formula (I) are formed.
Preferably, the methylmonosilanes of the general formula (I) formed in the process of the present invention include compounds selected from the group of: MeSihbCI, Me2SiH2, Me2SiHCI, Me3SiH, Me3SiCI, MeSiHC , Me2SiCI2 and MeSiH3.
Even more preferably, the methylmonosilanes of the general formula (I) formed in the process according to the invention include compounds selected from the group of Me2SiH2, Me2SiHCI and MeSiH2CI.
The one or more methyldisilanes subjected to the cleavage reaction of the silicon-silicon bond are represented by the general formula (II), wherein n = 1 to 5, preferably n = 2 to 5. Preferred starting materials of the general formula (II) include one or more of the compounds selected from MehbSi-SihbMe, Me2HSi-SiH2Me, Me2HSi-SiHMe2, Me3Si-SiHMe2, Me3Si- SiH2Me, MeH2Si-SiH3, Me2HSi-SiH3 and mixtures thereof.
Particularly preferred starting materials of the general formula (II) comprise one or more of the compounds selected from MehbSi-SihbMe, Me2HSi-SiH2Me, Me2HSi-SiHMe2 and mixtures thereof.
The present invention includes also the process wherein a substrate is reacted which comprises one or more methyldisilanes of the general formula (II), optionally in a mixture with other silanes not covered by general formula (I I) . The optional step of separating the resulting methylmonosilanes of the general formula (I) refers to any technical means applied to raise the content of one or several methylmonosilanes according to the general formula (I) in a product mixture, or which results in the separation of single compounds of the formula (I) from a product mixture obtained in step A) of the process according to the invention.
In a preferred embodiment of the process according to the invention, step A), i.e. subjecting one or more methyldisilanes of the general formula (I I) to the cleavage reaction of the silicon- silicon bond, is carried out by subjecting the methyldisilanes of the general formula (I I) to the reaction with hydrogen chloride (HCI) in the presence of an organic solvent, which is able to absorb or dissolve HCI and is able to cleave the Si-Si bond in the methyldisilanes in the presence of HCI.
In the sense of present invention, aprotic organic solvents are usually solvents that do not have a functional group from which hydrogen atoms can be split off as protons (dissociation) under the process conditions as opposed to the protic solvents. An aprotic organic solvent is any organic compound which is in liquid state at room temperature (about 23°C), and which is suitable as a medium for conducting the cleavage reactions therein. Accordingly, the aprotic organic solvent is preferably inert to hydrogen chloride under reaction conditions. Furthermore, the starting materials of the general formula (I I) and the products of the general formula (I) are preferably soluble in the organic solvent or fully miscible, respectively.
Furthermore, the term of "absorbing" or "absorption", each respectively, refers to the process of one material (absorbate), in this case hydrogen chloride, being retained by another (absorbent) , in this case the ether compound. The term of dissolving or dissolution, respectively, refers to the mixing of two phases with the formation of one new homogeneous phase, which in this case is a solution of hydrogen chloride in the ether compound.
In a further preferred embodiment of the process according to the invention, the aprotic organic solvent, which is present when step A) is carried out, is selected from one or more ether solvents.
In the present invention, the term "ether solvent" shall mean any organic compound containing an ether group -0-, in particular, of formula R1-O-R2, wherein Ri and R2 are independently selected from a monovalent organyl group, which is bonded to oxygen via a
carbon atom. Preferably, Ri and R2 are substituted or unsubstituted linear or branched alkyl groups or aryl groups, which may have further heteroatoms such as oxygen, nitrogen, or sulfur. In the case of cyclic ether compounds, Ri and R2 can constitute together an optionally substituted alkylene or arylene group, which may have further heteroatoms such as oxygen, nitrogen, or sulfur.
The ether compounds can be symmetrical or asymmetrical with respect to the substituents at the ether group -0-. In a further preferred embodiment, the ether solvents according to the invention are selected from the group consisting of linear and cyclic ether compounds.
Herein, a linear ether compound is a compound containing an ether group R1OR2 as defined above, in which there is no connection between the Ri and R2 group except the oxygen atom of the ether group, as for example in the symmetrical ethers Et20, n-Bu20, Ph20 or diisoamyl ether (/-Penty O), in which Ri = R2, or in unsymmetrical ethers as t-BuOMe (methyl f-butyl ether, MTBE) or PhOMe (methyl phenyl ether, anisol).
A cyclic ether compound according to the invention is a compound in which one or more ether groups are included in a ring formed by a series of atoms, such as for instance 1 ,4- dioxane, which can be substituted e.g. by alkyl groups.
In a preferred embodiment, the ether compound is selected from the group consisting of diethyl ether, di-n-butyl ether, dioxane, preferably diethyl ether and di-n-butyl ether.
In a further preferred embodiment, the ether compound is selected from 1 ,4-dioxane, diethyl ether or di-n-butyl ether.
In another preferred embodiment of the process according to the invention, step A) is carried out with an ether solvent containing HCI in saturated and diluted solutions.
In the sense of the present invention, the term "saturated" refers to a saturated solution of hydrogen chloride in the ether compound applied, and is defined as a solution which has the same concentration of a solute as one that is in equilibrium with undissolved solute at specified values of the temperature and pressure. In the sense of present invention, a solution being close to the state of saturation is also comprised by the term "saturated". Such saturated solution can be prepared by passing gaseous hydrogen chloride into the corresponding ether compound (e.g. diethyl ether, di-n-butyl ether) at about 5 to about 10°C. The ether is saturated when excess HCI gas is evaporated over the overpressure valve as
fast as it is introduced into the solvent. Diluted solutions are prepared stopping HCI- introduction into ethers before saturation or by dilution of saturated ether/HCI solutions with the corresponding pure ether solvent. Preferably, the HCI content of the ether solvent in the reaction step A) is > about 0.1 mol/l, more preferred > about 1.0 mol/l, even more preferred > about 3 mol/l, and most preferably the ether solvent is saturated with HCI as defined above.
Further preferably the HCI content of the ether solvent is > about 1 mol/l, even more preferred about 2 mol/l, and most preferably < about 3 mol/l, that is, in a preferred embodiment, the HCI content of the ether solvent is not "saturated".
In the context of this invention, it is also referred to Et20 used as solvent containing HCI as HCI/diethyl ether reagent, it is referred to di-n-butyl ether used as solvent containing HCI as HCI/di-n-butyl ether reagent, and it is referred to 1 ,4-dioxane used as solvent containing HCI as HCI/1 ,4-dioxane reagent.
Generally, increasing the HCI concentrations in ethers facilitates disilane chlorination SiH - SiCI which competes with disilane cleavage, while decreasing of the HCI concentrations facilitates disilane cleavage into SiH/SiCI substituted monosilanes, although longer reaction times are required. Furthermore, decreasing the reaction temperature facilitates disilane chlorination, while disilane cleavage reactions are preferred at elevated temperatures. The higher the degree of methylation at the backbone, the more disilane cleavage is favored, the higher the degree of hydrogenation, the higher the rate of chlorination, e.g. Me2Si2H4 is chlorinated to a greater extent than Me4Si2H2 under comparable conditions. As soon as a hydrogen substituent is replaced by chloride, subsequent disilane cleavage is inhibited. In case of the HCI/1 ,4-dioxane reagent chlorinated disilanes that are formed competitively to monosilanes from disilane cleavage, do not form siloxanes upon heating the samples. Reason for that is obviously the high stability of the cyclic ether against cleavage with HCI under moderate conditions.
In another preferred embodiment of the invention, step A) is carried out with diethyl ether saturated with HCI serving as the ether solvent saturated with HCI. Preferably, the saturation of the diethyl ether with hydrogen chloride is performed as described above, by passing gaseous hydrogen chloride into diethyl ether.
In a preferred embodiment of the process according to the invention, during or after the cleavage reaction also a chlorination of methylhydridomonosilanes takes place.
Herein, the term "chlorination" refers to the replacement of one, two or three, preferably one or two Si-H bonds by Si-CI bonds. The methylhydridomonosilanes which are chlorinated during or after the cleavage reaction are methylmonosilanes of the general formula (I), wherein y is at least 1 , preferably 2 or 3.
By the chlorination as described above, methylmonochlorohydridomonosilanes which are methylmonosilanes of the general formula (I), wherein z is 1 or 2, are formed.
Preferably, MeSiH3 is chlorinated to MeSiH2CI, MeSiH3 is dichlorinated to MeSiHC , Me2SiH2 is chlorinated to Me2SiHCI and Me3SiH is chlorinated to Me3SiCI. In a further preferred embodiment according to the invention, step A) is conducted at a temperature of about 0 °C to about 140 °C, preferably about 20 to about 120 °C, more preferably about 60 °C to about 100 °C.
Herein, the reaction temperature in step A) according to the invention is the temperature of the reaction mixture, i.e. the temperature measured inside the reaction vessel in which the reaction is conducted.
Preferably, the reaction vessel can be an ampoule, a sealed tube, a flask or any kind of chemical reactor, without being limited thereto.
The cleavage of methylhydridodisilanes of the general formula (II) into methylchlorohydridomonosilanes and methylhydridomonosilanes, each of the general formula (I), already occurs at room temperature in Et20 in the presence of HCI. The chlorination reaction involving Si-H to Si-CI exchange in methylhydridomonosilanes to give methylmonochlorohydridomonosilanes and hydrogen gas formation also takes place. Increasing the reaction temperatures to about 50 - about 80 °C accelerates both reactions.
In another preferred embodiment of the process according to the invention, the step A) is conducted at a pressure of about 1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
The indicated pressure ranges refer to the pressure measured inside the reaction vessel used when conducting reaction step A).
In a preferred embodiment of the process according to the invention, in the step A) the molar ratio of the hydrogen chloride to the methylhydridodisilanes of the general formula (II) is at least about 1 :1 , more preferably in the range of about 1 : 1 to about 4:1.
Herein, the molar ratio is defined as n (HCI added to the mixture of reaction step A) / n (methylhydridodisilanes of the general formula (II) ).
For the determination of this ratio, all compounds being methylhydridodisilanes of the general formula (II) submitted to the reaction step (A) are considered, regardless if they are submitted in an isolated or pure form, or if they are part of a mixture comprising other compounds, in particular disilanes and carbodisilanes, which do not fall under the general formula (II).
In a further preferred embodiment of the process according to the invention, in the step A) the weight ratio of the methylhydridodisilanes of the general formula (II) to the organic solvent is less than about 1 :2, preferably in the range of about 1 :2 to about 1 :20.
Herein, the weight ratio is defined as m (methylhydridodisilanes of the general formula (II) ) / m (organic solvent).
For the determination of this ratio, all compounds being methyldisilanes of the general formula (II) submitted to the reaction step (A) are considered, regardless if they are submitted as a part of a mixture comprising other compounds, in particular disilanes and carbodisilanes, which do not fall under the general formula (II). Furthermore, the mass of any organic solvent according to above definition of the term "organic solvent" present in the reaction mixture submitted to reaction step (A) is considered in the determination of the weight ratio.
In another preferred embodiment of the process according to the invention, in the step A) the weight ratio of the hydrogen chloride to the organic solvent is less than about 1 :5, preferably in the range of about 1 :5 to about 1 :30.
Herein, the weight ratio is defined as m (hydrogen chloride) / m (organic solvent). For the determination of this ratio, the mass of any organic solvent according to above definition of the term "organic solvent" present in the reaction mixture submitted to reaction step (A) is considered.
In a further preferred embodiment of the process according to the invention, the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSihbCI, MeSiHC , Me3SiCI, Me3SiH, MeSih , Me2SiCI2 and Me2SiH2 and mixtures thereof.
In a particularly preferred embodiment of the process according to the invention, the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiH2CI, MeSiHCb, Me2SiH2 and MeSiH3 and mixtures thereof.
In a preferred embodiment of the process according to the invention, dimethylmonosilane Me2SiH2 is formed by submitting a substrate selected from the group consisting of Me2HSi-SiHMe2, Me2HSi-SiH2Me, Me2HSi-SiH3 or Me2HSi-SiMe3 to the cleavage reaction of the Si-Si bond.
Therein, each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II). In a further preferred embodiment of the process according to the invention, methylmonosilane MeSiH3 is formed by submitting a substrate selected from the group consisting of MeH2Si-SiH2Me, MeH2Si-SiHMe2, MeH2Si-SiMe3 or MeH2Si-SiH3 to the cleavage reaction of the Si-Si bond.
Therein, each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II).
In another preferred embodiment of the process according to the invention, dimethylchloromonosilane Me2SiHCI is formed by submitting a substrate selected from the group consisting of Me2HSi-SiHMe2, Me2HSi-SiH2Me, Me2HSi-SiH3 or Me2HSi-SiMe3 to the cleavage reaction of the Si-Si bond.
Therein, each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II). In a further preferred embodiment of the process according to the invention, methylchloromonosilane MeSiH2CI is formed by submitting a substrate selected from the group consisting of MehbSi-SihbMe, MeH2Si-SiHMe2, MehbSi-Sih or MeH2Si-SiMe3 to the cleavage reaction of the Si-Si bond.
Therein, each of the above-stated substrates may be submitted to the reaction conditions as single substrate, in a mixture with other compounds of the above-stated compounds, or in a mixture with other substrates of the general formula (II).
In another preferred embodiment of the process according to the invention, the step of separating the resulting methylmonosilanes of the formula (I) is carried out by distillation. The term "distillation" in the sense of the present invention relates to any process for separating components or substances from a liquid mixture by selective evaporation and condensation. Therein, distillation may result in practically complete separation, leading to the isolation of nearly pure components, or it may be a partial separation that increases the concentration of selected components of the mixture.
The distillation processes, which may constitute separation step B), can be simple distillation, fractional distillation, vacuum distillation, short path distillation or any other kind of distillation known to the skilled person. The step B) of separating the chlorosilanes of the formula (I) according to the invention can comprise one or more batch distillation steps, or can comprise a continuous distillation process.
In a further preferred embodiment of the process according to the invention, the methylhydridodisilanes of the general formula (II) are obtained by hydrogenation of the corresponding methylchlorodisilanes of the general formula (III)
MenSi2CI6-n (IN),
wherein n is as defined above. Such methylchlorodisilanes are preferably residues from the Rochow-Muller Direct Process, and preferably contain mixtures of methylchlorodisilanes of formula (III).
In the present invention, the term "hydrogenation" is understood as substitution of one or more chloro substituents on the silicon atoms of the methylchlorodisilanes of the general formula (III) by one or more hydrogen atoms. Thus, the term "hydrogenation" refers to the transformation of one or more Si-CI bonds to one or more Si-H bonds.
Preferably, the starting material of the hydrogenation step of the general formula (I II) comprises one or more of the compounds selected from MeCI2Si-SiCI2Me, Me2CISi- SiC Me, Me2CISi-SiCIMe2, Me3Si-SiCIMe2, Me3Si-SiCI2Me, MeC Si-SiC , Me2CISi-SiCI3 and mixtures thereof.
Particularly preferred starting materials of the general formula (III) comprise one or more of the compounds selected from MeCI2Si-SiCI2Me, Me2CISi-SiCI2Me, Me2CISi-SiCIMe2 and mixtures thereof.
The present invention includes also the case where substrates are subjected to hydrogenation which comprise one or more methylchlorodisilanes of the general formula (III) in admixture with other silanes not covered by general formula (I II).
In a further preferred embodiment of the invention, hydrogenation is carried out with a hydride donor, selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH4, n-Bu3SnH, NaBH4, (;'-Bu2AIH)2 or sodium bis(2- methoxyethoxy)aluminumhydride, which is commercially available under the trademarks Vitride® or Red-AI®, for instance.
In the sense of present invention, a hydride donor is any compound being capable of providing hydride anions for the transformation of methylchlorodisilanes of the formula (III) to methylhydridodisilanes of the formula (II).
In the sense of present invention, the term metal hydride refers to any hydride donor containing at least one metal atom or metal ion.
The term "complex metal hydrides" according to the invention refers to metal salts wherein the anions contain hydrides. Typically, complex metal hydrides contain more than one type of metal or metalloid. As there is neither a standard definition of a metalloid nor complete agreement on the elements appropriately classified as such, in the sense of present invention the term "metalloid" comprises the elements boron, silicon, germanium, arsenic, antimony, tellurium, carbon, aluminum, selenium, polonium, and astatine.
In another preferred embodiment, the methylchlorodisilanes of the general formula (III) which are subjected to hydrogenation are residues of the Rochow-Muller Direct Process (DPR).
The primary commercial method to prepare alkylhalosilanes and arylhalosilanes is through the Rochow-Muller Direct Process (also called Direct Synthesis or Direct Reaction), in which copper-activated silicon is reacted with the corresponding organohalide, in particular methyl chloride, in a gas-solid or slurry-phase reactor. Gaseous products and unreacted organohalide, along with fine particulates, are continuously removed from the reactor. Hot effluent exiting from the reactor comprises a mixture of copper, metal halides, silicon, silicides, carbon, gaseous organohalide, organohalosilanes, organohalodisilanes, carbosilanes and hydrocarbons. Typically, this mixture is first subjected to gas-solid separation in cyclones and filters. Then the gaseous mixture and ultrafine solids are condensed in a settler or slurry tank from which the organohalide, organohalosilanes, hydrocarbons and a portion of organohalodisilanes and carbosilanes are evaporated and sent to fractional distillation to recover the organohalosilane monomers. The solids accumulated in the settler along with the less volatile silicon-containing compounds are purged periodically and sent to waste disposal or to secondary treatment. Organohalodisilanes and carbosilanes left in the post-distillation residues are also fed to hydrochlorination. Organohalodisilanes, organohalopolysilanes and carbosilanes, related siloxanes and hydrocarbons, either in the post-distillation residues or in the slurry purged from the reactor, boil above orgaohalosilane monomers. Collectively they are referred to as Direct Process Residue (DPR). The terms higher boilers, high-boiling residue and disilane fraction are also used interchangeably with DPR.
By the process according to the invention, methylchlorodisilanes of the general formula (I II) which are obtained as a constituent of the side-products of the Rochow-Muller Direct Process (DPR) can be transformed in particular to methylhydridosilanes of the general formula (I) via hydrogenation to methylhydridodisilanes of the general formula (II) and subsequent cleavage of the silicon-silicon bond as described.
According to the invention, the Direct Process Residue (DPR) utilized as starting material may comprise further silicon-based compounds which do not fall under general formula (III). In a further preferred embodiment, the process according to the invention is performed under inert conditions.
In the sense of present invention, the term "performed under inert conditions" means that the process is partially or completely carried out under the exclusion of surrounding air, in particular of moisture and oxygen. In order to exclude ambient air from the reaction mixture and the reaction products, closed reaction vessels, reduced pressure and/or inert gases, in particular nitrogen or argon, or combinations of such means may be used.
Preferred embodiments of the invention:
In the following the preferred embodiments of the invention are shown:
1 . Process for the manufacture of methylmonosilanes of the general formula (I):
MexSiHyClz (I),
wherein
x = 1 to 3,
y = 0 to 3,
z = 0 to 2 and
x + y + z = 4,
comprising :
A) the step of subjecting one or more methyldisilanes of the general formula (I I)
MenSi2H6i.-n (II)
wherein n = 1 to 6, preferably 1 to 5,
to the cleavage reaction of the silicon-silicon bond, and
B) optionally a step of separating the resulting methylmonosilanes of the formula (I) , wherein step A) is carried out by subjecting the methylhydndodisilanes of the general formula (II) to the reaction with hydrogen chloride (HCI) in the presence of one or more aprotic organic solvents.
(Aprotic organic solvents are usually solvents that do not have a functional group from which hydrogen atoms can be split off as protons (dissociation) under the process conditions as opposed to the protic solvents).
2. The process according to embodiment 1 , wherein said aprotic organic solvent(s) is/are able to absorb or dissolve HCI and is/are able to cleave Si-Si bonds in the presence of HCI.
3. The process according to embodiments 1 or 2, wherein said aprotic organic solvent is selected from one or more ether solvents.
4. The process according to embodiment 3, wherein said ether solvents are selected from the group consisting of linear and cyclic ether compounds.
5. The process according to embodiment 4, wherein the ether compound is selected from the group consisting of diethyl ether, di-n-butyl ether, dioxane, preferably diethyl ether and din-butyl ether.
6. The process according to any of the previous embodiments, wherein the ether compound is selected from 1 ,4-dioxane, diethyl ether or di-n-butyl ether.
7. The process according to any of the previous embodiments, wherein step A) is carried out with an ether solvent unsaturated or saturated with HCI, preferably an ether solvent saturated with HCI, preferably the ether solvent is diethylether.
8. The process according to the previous embodiments, wherein step A) is carried out with diethyl ether/HCI solutions of molarities in the range of about 0.5 to about 10 mol/L, preferably 1 to 6 mol/L (the solutions may have a temperature in the range of 0 to 25 °C).
9. The process according to any of the previous embodiments, wherein during or after the cleavage reaction also a chlorination of methylhydridomonosilanes takes place.
10. The process according to any of the previous embodiments, wherein the step A) is conducted at a temperature of about 0 °C to about 140 °C, preferably about 20 to about 120
°C, more preferably about 60 °C to about 100 °C.
1 1 . The process according to any of the previous embodiments, wherein the step A) is conducted at a pressure of about 1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
12. The process according to any of the previous embodiments, wherein in the step A) the molar ratio of the hydrogen chloride to the methylhydridodisilanes of the general formula (II) is at least about 1 : 1 , more preferably in the range of about 1 : 1 to about 4: 1 .
13. The process according to any of the previous embodiments, wherein in the step A) the weight ratio of the methylhydridodisilanes of the general formula (II) to the organic solvent is less than about 1 :2, preferably in the range of about 1 :2 to about 1 :20.
14. The process according to any of the previous embodiments, wherein in the step A) the weight ratio of the hydrogen chloride to the aprotic organic solvent is less than about 1 :5, preferably in the range of about 1 :5 to about 1 :30.
15. The process according to any of the previous embodiments, wherein the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI,
MeSiH2CI, MeSiHC , Me3SiCI, Me3SiH, MeSiH3, Me2SiCb and Me2SiH2.
16. The process according to any of the previous embodiments, wherein the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiH2CI, MeSiHCb, Me2SiH2 and MeSiH3.
17. The process according to any of the previous embodiments, wherein dimethylmonosilane Me2SiH2 is formed by submitting a substrate selected from the group consisting of Me2HSi-SiHMe2, Me2HSi-SiH2Me, Me2HSi-SiH3 or Me2HSi-SiMe3 to the cleavage reaction of the Si-Si bond.
18. The process according to any of the embodiments 1 to 16, wherein methylmonosilane MeSiH3 is formed by submitting a substrate selected from the group consisting of
MeH2Si-SiH2Me, MeH2Si-SiHMe2, MeH2Si-SiMe3 or MeH2Si-SiH3 to the cleavage reaction of the Si-Si bond.
19. The process according to any of the embodiments 1 to 16, wherein dimethylchloromonosilane Me2SiHCI is formed by submitting a substrate selected from the group consisting of Me2HSi-SiHMe2, Me2HSi-SiH2Me, Me2HSi-SiH3 or Me2HSi-SiMe3 to the cleavage reaction of the Si-Si bond.
20. The process according to any of the embodiments 1 to 16, wherein methylchloromonosilane MeSiH2CI is formed by submitting a substrate selected from the group consisting of MeH2Si-SiH2Me, MeH2Si-SiHMe2, MeH2Si-SiH3 or MeH2Si-SiMe3 to the cleavage reaction of the Si-Si bond.
21 . The process according to any of the previous embodiments, wherein the step of separating the resulting methylmonosilanes of the formula (I) is carried out by distillation.
22. The process according to any of the previous embodiments, wherein the methylhydridodisilanes of the general formula (I I) are obtained by hydrogenation of the corresponding methylchlorodisilanes of the general formula (II I)
MenSi2CI6-n (IN) ,
wherein n is as defined above.
23. The process according to the previous embodiments, wherein the hydrogenation is carried out with one or more hydride donors, selected from the group of metal hydrides, preferably complex metal hydrides such as LiAIH4, n-Bu3SnH, NaBH4, (/'-Bu2AIH)2 or sodium bis(2-methoxyethoxy)aluminumhydride.
24. The process according to any of the previous embodiments, wherein the methylchlorodisilanes of the general formula (I I I) are residues of the Rochow-Muller Direct Process (DPR) .
25. The process according to any of the previous embodiments, wherein the process is performed under inert conditions.
26. Methylmonosilanes of the general formula (I) as defined above, as obtainable by the process according to any of the previous embodiments.
27. Compositions comprising at least one methylmonosilane of the general formula (I) as defined above, as obtainable by the process according to any of the previous embodiments.
EXAMPLES
The present invention is further illustrated by the following examples, without being limited thereto. General
To obtain the starting materials of the general formula (II), the methylchlorodisilanes of the general formula (III) MenSi2Cl6-n (n=1 -5) were converted into their corresponding methylhydridodisilanes MenSi2H6-n (n=1 -5) by hydrogenation with conventional hydrogenating reagents, such as complex metal hydrides (LiAIH4, NaBH4, ((/-Bu2AIH)2 etc.) or mixtures thereof in ethers as solvents (e.g. diethyl ether, di-n-butyl ether, diglyme, 1 ,4-dioxane or mixtures thereof).
The methylhydridodisilanes of the general formula (II) were cleaved into the corresponding monosilanes of the general formula (I) by reaction with a HCI/ether solution (2-5 molar (= mol/l) in Et20, 1 -6 molar in n-Bu20). The complex reaction mixtures were analyzed by NMR- spectroscopy. The molar ratios of products formed were determined by integration of relevant NMR signals, which are assigned to specific products within the mixture.
The amount of products formed can be estimated by the molar ratios as measured by NMR spectroscopy and the amount of starting material applied (0.1 ml), assuming a density of 1 g/cm3 of the starting materials.
Preparation of HCI/ether solutions
Gaseous hydrogen chloride was slowly passed into the corresponding ether (diethyl ether, di-n-butyl ether, 1 ,4-dioxane) at about 5 to about 10°C. The ether was saturated when excess HCI gas was evaporating over the overpressure valve as fast as it was introduced into the solvent. Diluted solutions were prepared stopping HCI introduction into the ethers before saturation or by dilution of saturated ether/HCI solutions with the corresponding pure ether solvent. The molarity was 2-5 molar in Et20, and 1 -6 molar for HCI in in n-Bu20. The molarity of the HCI/ether reagent was determined by weighing the solutions: The obtained concentrations for saturated solutions were about 6 mol/l for HCI in di-n-butyl ether and about 5 mol/l for HCI in diethyl ether, and about 8-14 mol/l in 1 ,4-dioxane, depending on the amount of HCI introduced. The molarities of the HCI/ether solutions weighed were additionally confirmed by titration of HCI against sodium hydroxide (NaOH).
General observations
The cleavage of methylhydridodisilanes into methylchlorohydridomonosilanes and methylhydridomonosilanes already starts at room temperature, and is accelerated at elevated temperatures and with increasing HCI concentrations in the ether solvents. In addition Si-H - Si-CI exchange in methylhydridomonosilanes to give methylmonochlorohydridomonosilanes and hydrogen gas was detected. Increasing the reaction temperatures from about 50 to about 80 °C accelerates both reactions. This is convincingly documented in the following tables. It should be noted that most cleavage and Si-CI - Si-H reduction experiments of disilane mixtures were performed with the HCI/diethyl ether reagent under optimum conditions for disilane cleavage (e.g. concentration of HCI ca. 2-3.5 mol/l; disilane chlorination (< 1 %) is omitted in the Tables), while pure disilanes were exemplarily reacted with the HCI/n-Bu20 reagent under concentration and temperature dependent reaction conditions. These experiments clearly demonstrate the strong influence of HCI concentrations in ethers and on reaction temperatures on the competitive formation of monosilanes and chlorinated disilanes. Generally, di-n-butyl ether decelerates cleavage and chlorination reaction compared to diethyl ether (~ 5 mol/l HCI each): For a comparison of product formation in different ethers as solvents for HCI it should be noted that cleavage/chlorination reactions have to be performed under strictly comparable conditions (HCI concentration and reaction temperature control)! Reaction times are given in the tables for complete consumption of disilanes and/or hydrogen chloride.
Identification of compounds
Products were analyzed by 1H, 29Si, 1H-29Si-HSQC and 1H-29Si-HMBC NMR spectroscopy. The spectra were recorded on a Bruker AV-500 spectrometer equipped with a Prodigy BBO 500 S1 probe. 1H NMR spectra were calibrated to the residual solvent proton resonance ([D6]benzene 5H = 7.16 ppm). Product identification was additionally supported by GC-MS analyses and verified identification of the main products. GC-MS analyses were measured with a Thermo Scientific Trace GC Ultra coupled with an ITQ 900MS mass spectrometer. The stationary phase (Machery-Nagel PERMABOND Silane) had a length of 50 m with an inner diameter of 0.32 mm. 1 μΙ of analyte solution was injected, 1/25 thereof was transferred onto the column with a flow rate of 1 .7 mL/min carried by Helium gas. The temperature of the column was first kept at 50 °C for 10 minutes. Temperature was then elevated at a rate of 20 °C/min up to 250 °C and held at that temperature for another 40 minutes. After exiting the column, substances were ionized with 70 eV and cationic fragments were measured within a range of 34 - 600 m/z (mass per charge). Product mixtures were diluted with benzene prior to the measurement.
The characteristic 29Si-NMR chemical shifts and coupling constants J{29Si-1H} for compounds I to XXII are listed in Table 1.
Table 1
Example 1 :
(General procedure) Synthesis of methylhydridodisilanes from methylchlorodisilanes by the use of LiAlhU as hydroqenatinq reagent
LiAIH4 (10% molar excess) was placed in a three neck flask and ether was added as solvent. Diethyl ether was used for high boiling methylhydridodisilanes of the general formula (II) and di-n-butyl ether, 1 ,4-dioxane or diglyme for low boiling disilanes of the general formula (II) to facilitate product separation by distillation at normal or reduced pressure. After cooling the ether/LiAIH4 suspension to temperatures between -40 and 0 °C the methylchlorodisilane of the general formula (III) or a mixture comprising more than one methylchlorodisilane of the general formula (III) were added dropwise and slowly by a dropping funnel. After completion the resulting mixture was stirred for an additional hour at low temperature and then slowly warmed to r.t. and stirred for additional 12 hours to complete hydrogenation. The resulting
methylhydridodisilanes of the general formula (II) were separated by condensation/distillation in vacuo and characterized NMR spectroscopically.
HCI/ether-cleavaqe of methylhydridodisilanes into the corresponding methylchlorohvdrido- and methylhydridomonosilanes
0.1 ml of a methylhydridodisilane of the general formula (II) or a mixture comprising more than one methylhydridodisilanes of the general formula (II) were dissolved in 0.1 ml C6D6 and placed in an NMR tube. After cooling to -196 °C (liquid nitrogen), 0.4 ml to 0.6 ml HCI/ether reagent were added, cooled (-196 °C), evacuated in vacuo and sealed. The cleavage reactions were performed in sealed NMR tubes to prevent evaporation of low boiling products and to control the cleavage reaction proceeding at different temperatures. After warming the sample to r.t. it was measured by NMR-spectroscopy and then reacted at different temperatures to control and quantify product formation (e.g. by integration of the intensity of relevant 29Si-NMR signals within the product mixture).
Example 2:
A sample of methylhydridodisilanes I to III (0.1 ml) and V was reacted with the HCI/diethyl ether reagent (<5 molar, 0.4 ml) for 130 hours at 50 °C. As detected by NMR-spectroscopy 89% of the disilane MeH2Si-SiH2Me were already cleaved after 18 hours. About 50% of the resulting methylsilane (MeSiH3) were already converted into monochlorinated MeSiH2CI. After 130 hours nearly all disilanes were cleaved and methylsilane was transferred into methylchlorosilane in high yield (84%). In the same way Me2SiH2 (VIII) was slowly converted into Me2Si(H)CI. Table 2 shows molar educt/product ratios at 50 °C with increasing reaction times. With increasing reaction times MeSiH3 was slightly dichlorinated to give methyldichlorosilane XIV in small amounts.
Table 2
A mixture of the disilanes I to III (0.1 ml) was reacted with the HCI/di-n-butyl ether reagent (4.8 molar, 0.6 ml). As can be seen from Table 3 the resulting monosilanes are comparable to those formed with the HCI/diethyl ether reagent, but the reaction temperatures are higher, obviously the HCI/di-n-butyl ether reagent is less reactive than HCI/diethyl ether:
The molar ratio of products formed at 80 °C (17.5 h) and at 100 °C (97 h) is listed in Table 3 and demonstrates that the disilanes were converted into methylmonochlorohydrido- VII and methylhydridomonosilanes VI and VIII, that subsequently reacted to methylchlorohydridomonosilanes by chlorination with hydrogen chloride. Prolonged reaction times at higher temperatures finally lead to double chlorination of methylsilane VI to increasingly give MeSiHC XIV.
Table 3
Example 4:
A sample of methylhydridodisilanes II to V (0.1 ml), mainly consisting of disilane III (81 %), was reacted with the HCI/diethyl ether reagent (<5 molar, 0.4 ml) for 17 hours and then 105 hours at 50 °C. As detected by NMR spectroscopy all disilanes were completely cleaved into the corresponding monosilanes already after 17 hours. Comparing the molar product ratios demonstrates that after 105 hours reaction time dimethylsilane (Me2SiH2) was in part chlorinated into Me2Si(H)CI (50% vs. 62%). The HCI/ether reagent is both a Si-Si-bond cleavage and a Si-H - Si-CI chlorinating reagent. The products formed and their molar ratio in the product mixture are listed in Table 4.
Table 4
Example 5:
The cleavage reaction of the same disilane mixture of disilanes II to V (0.1 ml) as in example 4 with HCI/ether was performed in di-n-butyl ether (4.8 molar, 0.6 ml). As can be seen from Table 5 the resulting monosilanes are comparable to those formed with the HCI/diethyl ether reagent, but the reaction temperatures are higher (17 ½ hours at 80 °C and additional 97 hours at 100 °C). Prolonged reaction times at higher temperatures lead to mono and double chlorination of Me2SiH2 (VIII) to give preferably monochlorinated Me2SiHCI (IX) and in small amounts Me2SiC (XV). The products formed and their molar ratios in the product mixture are listed in Table 5.
Table 5
Example 6:
A mixture consisting of methylhydridodisilanes I, II, IV and V and of monosilane VIII (5%) (0.1 ml) was reacted with the HCI/Et20 reagent (<5 molar, 0.4 ml) at 50 °C for 88 hours. Table 6 shows that all disilanes were cleaved into methylmonochlorohydridosilanes and methylhydridomonosilanes, whereby chlorination of methylhydridomonosilanes VI and VIII into the monochlorosilanes VII and IX becomes more and more significant with prolonged reaction times (Table 6).
Table 6
Example 7:
A mixture of the methylhydndodisilanes I to I I I and V and the monosilanes VI and VI I I (0.1 ml) was reacted with the HCI/Et20 reagent (<5 molar, 0.4 ml) at 50 °C for 105 hours. Table 7 shows that all disilanes were already reacted into monosilanes after 17 hours giving mainly the chlorosilanes VI I and IX. The methylsilanes VI and VI I I were increasingly chlorinated by HCI/Et20 with increasing reaction time, finally giving compounds VI I in 38% and IX in 39% yield. With longer reaction times, the latter will be formed nearly quantitatively while VI I was already quantitatively formed from VI after 105 hours at 50 °C.
Table 7
Example 8:
A mixture of the methylhydndodisilanes I , I I I and V and the monosilane VI I I (0.1 ml) was reacted with the HCI/Et20 reagent (<5 molar, 0.4 ml) at 50 °C for 89 h. Table 8 shows that disilane cleavage is nearly quantitative giving mainly dimethylchlorosilane (IX, 64%). With prolonged reaction times, the yield of this compound is further increased by chlorination of dimethylsilane (VI I I) .
Table 8
Example 9:
A complex sample of methylhydridodisilanes and the monosilanes listed in Tables 6, 7 and 8, consisting of a 1 :1 :1-mixture (0.05 ml each) of the mixtures from Examples 6, 7 and 8 was reacted with the HCI/Et20 reagent (<5 molar, 0.6 ml) at 50 °C for 41 hours. Then the reaction temperature was increased to 80 °C for additional 15 hours and then raised to 100 °C for 97 hours. In Table 9 products formed upon increased reaction temperatures and times are listed. All the disilanes, except highly methylated disilane V, were already transferred into monosilanes after 41 hours at 50 °C. At 100 °C even disilane V was completely transformed. Finally, the complete mixture gives the methylchlorosilanes VII and IX nearly quantitatively (44% vs. 46%). Together with the formation of trimethylsilanes X and XI the complete disilane mixture is transferred into valuable monosilanes quantitatively.
Notably, with prolonged reaction time the methylsilanes VI and VIII are increasingly chlorinated into VII and IX at 80 °C. At 100 °C this transfer is quantitative with simultaneous formation of disiloxane Me2HSi-0-SiHMe2 (XIII) and chlorosilane XI.
Example 10:
From examples 1 to 9 it is evident that HCI/Et20-cleavage of methylhydridodisilanes becomes more and more difficult with increasing degree of methylation at the disilane backbone using comparable HCI concentrations and reaction temperatures. For demonstration, pentamethyldisilane, Me3Si-SiMe2H (V) (0.1 ml) was reacted with the cleavage reagent (<5 molar, 0.4 ml) at different temperatures (50 and 80 °C). The products formed are listed in Table 10.
Table 10
Disilane V is nearly completely cleaved at 80 °C forming monosilanes IX and X. Obviously the cleavage product Me2SiH2 (VIII) is mostly chlorinated to give chlorosilane IX.
Example 11
Methylhydridodisilane III (0.08 ml, containing 3 μΙ diglyme) was separately reacted with the HCI/Et20 reagent (<5 molar, 0.5 ml) and the HCI/1 ,4-dioxane reagent (12 molar, 0.4 ml) for 18 h at 60 °C.
Table 11
Tetramethyldisilane III was completely cleaved with HCI/Et20 in the presence of a small amount of diglyme in the solution. HCI/1 ,4-dioxane both cleaves and substitutes the SiH- SiH-moiety.
Example 12
Cleavage reactions of dimethyldisilane I with the HCI//J-BU2O reagent with different molar HCI-concentrations and at different reaction temperatures.
HO/nBuZO
Reactions: MeHrSi-SiHrMe— ♦ MeSiHs + MeSiH2CI
BQ/nBuZO BO/nBu20
MeSiHs— * MeSiH2CI— » MeSiHCb
The experimental results obtained are listed in Table 12.
Table 12
Comparing entries a) to d), e) to h) and i) to I) clearly proves that disilane cleavage is favored with comparable HCI concentrations with increasing reaction temperatures.
In the same way chlorination of hydridomonosilanes to give chlorinated products is supported, MeSiHs reacting faster do yield MeSiH2CI, double chlorination to give MeSiHCh requires high HCI concentrations as well as high reaction temperatures. Noteworthy, the highest rate of disilane cleavage was obtained at 100 °C/5 d with a 2.5M HCI/n-Bu20 solution to give 54% of MeSiH2CI and MeSiHCb (16.7%), while MeSiHs was detected in 7%. This is
obviously due to the competitive Si-H - Si-CI chlorination of the monosilanes formed by predominant disilane cleavage.
Example 13:
Cleavage reactions of tetramethyldisilane III with the HCI/n-Bu20 reagent with different molar HCI-concentrations and at different reaction temperatures.
BO/nBu20
Reactions: Me2HSi-SiHMe2 » Me2SiHCI + Me2SiH2
lCI niu20
Me2SiH2— » Me2SiHCI
The experimental results obtained are listed in Table 13 and show comparable trends as obtained for disilane I (Table 12).
Table 13
Increasing reaction temperatures with low HCI-concentrations (entries a-d) yield the monosilanes Me2SiHCI and Me2SiH2 quantitatively (d) with an increasing rate of monosilane
chlorination of Me2SiH2 to give Me2SiHCI. Chlorination of the disilane I I I occurs with high HCI concentrations at low temperatures (e.g. 41 % , entry i), increasing the temperature to 100 °C gives Me2SiHCI in 94% within one day, including nearly quantitative chlorination of Me2SiH2 first formed by disilane cleavage.
Example 14:
Cleavage reactions of pentamethyldisilane V with the HCI/n-Bu20 reagent with different molar HCI-concentrations and at different reaction temperatures.
BCl/aBuZD
Reactions: Me3Si-SiHMe2 Me2SiHCI + Me3SiH + Me2SiH2 + Me3SiCI
lCI/niu20
Me2SiH2 Me2SiHCI
BO/nBuZO
Me3SiH MesSiCI
The cleavage of pentamethyldisilane V with the HCI/n-Bu20 reagent was exemplarily performed with a 2.5M HCI-concentration. The experimental findings are listed in Table 14.
Table 14
At lower reaction temperatures (r.t.) only chlorination to give disilane XI I was detected.
Disilane cleavage started at 40 ' C, the chloride of HCI binding to the Me2SiH-moiety, while
the hydrogen atom binds to the Me3Si-unit. At 100 C the molar ratio Me2SiHCI/Me3SiH is nearly 1/1 (~ 42% each), cleavage was completed to give monosilanes quantitatively.
Example 15:
Cleavage reaction of hexamethyldisilane with the HCI/n-Bu20 reagent.
ΗΏ/nBuZO
Reactions: Me3Si-SiMe3 > Me3SiH + Me3SiCI
BO/ni ZO
Me3SiH » Me3SiCI
As can be concluded from Table 15, disilane cleavage with 2.5M HCI//7-BU2O is quantitative within 4 days at 100 C to give the expected monosilanes. While the molar ratio is about 1/1 after 1 and 2 days, longer reaction times initiate chlorination of Me3SiH - Me3SiCI with excess HCI in the sample.
Table 15
Example 16:
Cleavage reactions of different disilanes with the HCI/1 ,4-dioxane reagent with different HCI-concentrations at different reaction temperatures.
The disilanes listed in Table 16 were reacted with 2.5M and 5.5M solutions of HCI in 1 ,4- dioxane at 80-140 C. The products obtained from disilane cleavage and competitive chlorination reactions are listed in Table 16.
Table 16
As can be seen from entries a) and b) , increasing reaction temperatures supported disilane chlorination, the molar amount of monosilanes decreased from 74% to 36.5% with increasing T from 80 °C to 140 °C having the same HCI concentrations. Comparison of entries a) and c) show that an increase of the HCI concentration from 2.5M to 5.5M in 1 ,4-dioxane diminishes the amount of monosilanes from 74% to 61 %, formed at 80 °C. Reacting tetramethyldisilane I I I with a 2.5M HCI/1 ,4-dioxane solution at 80 °C and 140 °C gives excellent yields of Me2SiHCI by simultaneous cleavage of I I I and chlorination of Me2SiH2 with excess HCI. Notably, higher reaction temperatures shorten the reaction times. Higher HCI concentrations favor disilane chlorination (entry g). Pentamethyldisilane (V) is nearly quantitatively cleaved at 100 °C within 1 day to give the expected products.
Example 17:
A sample of methyldisilanes I, I I , I I I , IV and V (0.1 ml) (molar composition see Table 17) was reacted with the HCI/n-Bu20 reagent (2.5M) at increasing reaction temperatures and with different reaction times. Products formed upon disilane cleavage/chlorination with subsequent monosilane chlorination are depicted in Table 18.
Table 17
Table 18
Optimum conditions for the formation of monosilanes were identified at T=80 °C for 10 days: Me2SiHCI (31 %) , Me2SiH2 (13%), MeSiHCI2 (8%), MeSiH2CI (39%) formed predominantly, while chlorinated disilanes formed in about 5% . Interestingly, the molar amount of Me2SiHCI (>39%) increased while that of MeSiH2CI was decreased increasing the reaction temperature to 100 °C, but the competitive disilane chlorination was increased giving 10% of chlorinated derivatives.
While the above description contains many specifics, these specifics should not be construed as limitations on the scope of the invention, but merely as exemplifications of preferred embodiments thereof. Those skilled in the art may envision many other possible variations that are within the scope and spirit of the invention as defined by the claims appended hereto.
Example 18: A mixture of the highly methylated disilanes CIMe2Si-SiMe2CI (50%) , Me3Si-SiMe2CI (25%) and Me3Si-SiMe3 (25%) were mixed and reacted in n-Bu20 with LiH to give per hydrogenated methyldisilanes listed in Table 19.
The per hydrogenated disilanes were then reacted with a 2.5M n-Bu20/HCI solution at 100°C for 3 days to give quantitative cleavage of the highly methylated disilanes to form the most valuable monosilanes Me2SiHCI, Me3SiH, and Me3SiCI. Molar amounts of products formed are listed in Table 20. No oligomeric structures were detected 29Si-NMR spectroscopically.
Claims
1 Process for the manufacture of methylmonosilanes of the general formula (I): MexSiHyClz (I),
wherein
x = 1 to 3,
y = 0 to 3,
z = 0 to 2 and
x + y + z = 4,
comprising:
A) the step of subjecting one or more methyldisilanes of the general formula (II) MenSi2H6-n (II) wherein n = 1 to 6, preferably 1 to 5,
to the cleavage reaction of the silicon-silicon bond, and
B) optionally a step of separating the resulting methylmonosilanes of the formula (I), wherein step A) is carried out by subjecting the methylhydndodisilanes of the general formula (II) to the reaction with hydrogen chloride (HCI) in the presence of one or more aprotic organic solvents.
2. The process according to claim 1 , wherein said aprotic organic solvent(s) is/are able to absorb or dissolve HCI and is/are able to cleave Si-Si bonds in the presence of HCI.
3. The process according to claims 1 or 2, wherein said aprotic organic solvent is selected from one or more ether solvents.
4. The process according to claim 3, wherein the ether compound is selected from the group consisting of diethyl ether, di-n-butyl ether, dioxane, preferably diethyl ether and di-n- butyl ether.
5. The process according to any of the previous claims, wherein step A) is carried out with an ether solvent unsaturated or saturated with HCI, preferably saturated with HCI.
6. The process according to any of the previous claims, wherein during or after the cleavage reaction also a chlorination of methylhydridomonosilanes takes place.
7. The process according to any of the previous claims, wherein the step A) is conducted at a temperature of about 0 °C to about 140 °C, preferably about 20 to about 120 °C, more preferably about 60 °C to about 100 °C.
8. The process according to any of the previous claims, wherein the step A) is conducted at a pressure of about 1 bar to about 30 bar, preferably about 1 bar to about 20 bar, most preferably about 1 bar to about 10 bar.
9. The process according to any of the previous claims, wherein in the step A) the molar ratio of the hydrogen chloride to the methylhydridodisilanes of the general formula (II) is at least about 1 : 1 , more preferably in the range of about 1 : 1 to about 4: 1 .
10. The process according to any of the previous claims, wherein in the step A) the weight ratio of the hydrogen chloride to the aprotic organic solvent is less than about 1 :5, preferably in the range of about 1 :5 to about 1 :30.
1 1 . The process according to any of the previous claims, wherein the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiH2CI, MeSiHC , MesSiCI, Me3SiH, MeSihh, Me2SiCl2 and Me2SiH2, preferably the methylmonosilanes of the formula (I) are selected from the group consisting of Me2SiHCI, MeSiH2CI, MeSiHC , Me2SiH2 and MeSiH3.
12. The process according to any of the previous claims, wherein dimethylmonosilane Me2SiH2 is formed by submitting a substrate selected from the group consisting of Me2HSi-SiHMe2, Me2HSi-SiH2Me, Me2HSi-SiH3 or Me2HSi-SiMe3 to the cleavage reaction of the Si-Si bond, or wherein methylmonosilane MeSiH3 is formed by submitting a substrate selected from the group consisting of MehbSi-SihbMe, MeH2Si-SiHMe2, MeH2Si-SiMe3 or Meh Si-Sihh to the cleavage reaction of the Si-Si bond, or wherein dimethylchloromonosilane Me2SiHCI is formed by submitting a substrate selected from the group consisting of Me2HSi-SiHMe2, Me2HSi-SiH2Me, Me2HSi-SiH3 or Me2HSi-SiMe3 to the cleavage reaction of the Si-Si bond, or wherein methylchloromonosilane MeSihbCI is formed by submitting a substrate selected from the group consisting of MehbSi-SihbMe, MeH2Si- SiHMe2, MeH2Si-SiH3 or MeH2Si-SiMe3 to the cleavage reaction of the Si-Si bond.
13. The process according to any of the previous claims, wherein the methylhydridodisilanes of the general formula (II) are obtained by hydrogenation of the corresponding methylchlorodisilanes of the general formula (II I)
MenSi2CI6-n (IN),
wherein n is as defined above.
14. The process according to the previous claim, wherein the hydrogenation is carried out with one or more hydride donors, selected from the group of metal hydrides, preferably
complex metal hydrides such as LiAIH4, n-Bu3SnH, NaBH4, ('-Bu2AIH)2 or sodium bis(2- methoxyethoxy)aluminum hydride.
15. The process according to any of the previous claims, wherein the methylchlorodisilanes of the general formula (III) are residues of the Rochow-Muller Direct Process (DPR).
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4291167A (en) | 1980-07-28 | 1981-09-22 | Nalco Chemical Company | Preparation of tetramethyldisilane from 1,2-tetramethyldichlorodisilane |
DD274227A1 (en) | 1988-07-19 | 1989-12-13 | Univ Rostock | PROCESS FOR PREPARING CHLORO-METHYL-SILANES FROM CHLORINE-METHYL-DISILANES |
US5288892A (en) | 1992-06-19 | 1994-02-22 | Wacker-Chemie Gmbh | Separation of methylchlorosilanes from high boiling residues of methylchlorosilane synthesis |
WO2013101618A1 (en) | 2011-12-30 | 2013-07-04 | Momentive Performance Materials Inc. | Synthesis of organohalosilane monomers via enhanced cleavage of direct process residue |
WO2013101619A1 (en) | 2011-12-30 | 2013-07-04 | Momentive Performance Materials Inc. | Synthesis of organohalosilane monomers from conventionally uncleavable direct process residue |
-
2018
- 2018-09-20 WO PCT/US2018/051851 patent/WO2019060479A1/en active Application Filing
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4291167A (en) | 1980-07-28 | 1981-09-22 | Nalco Chemical Company | Preparation of tetramethyldisilane from 1,2-tetramethyldichlorodisilane |
DD274227A1 (en) | 1988-07-19 | 1989-12-13 | Univ Rostock | PROCESS FOR PREPARING CHLORO-METHYL-SILANES FROM CHLORINE-METHYL-DISILANES |
US5288892A (en) | 1992-06-19 | 1994-02-22 | Wacker-Chemie Gmbh | Separation of methylchlorosilanes from high boiling residues of methylchlorosilane synthesis |
EP0574912B1 (en) | 1992-06-19 | 1999-01-07 | Wacker-Chemie GmbH | Process for the preparation of methylchlorosilanes from the high-boiling residue obtained through this direct process |
WO2013101618A1 (en) | 2011-12-30 | 2013-07-04 | Momentive Performance Materials Inc. | Synthesis of organohalosilane monomers via enhanced cleavage of direct process residue |
WO2013101619A1 (en) | 2011-12-30 | 2013-07-04 | Momentive Performance Materials Inc. | Synthesis of organohalosilane monomers from conventionally uncleavable direct process residue |
US8637695B2 (en) | 2011-12-30 | 2014-01-28 | Momentive Performance Materials Inc. | Synthesis of organohalosilane monomers from conventionally uncleavable Direct Process Residue |
US8697901B2 (en) | 2011-12-30 | 2014-04-15 | Momentive Performance Materials Inc. | Synthesis of organohalosilane monomers via enhanced cleavage of direct process residue |
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