Process for producing isomer enriched higher silanes

Patent metadata

Field	Value
Publication number	US-11401166-B2
Application number	US-201916409326-A
Country	US
Kind code	B2
Filing date	May 10, 2019
Priority date	Oct 11, 2018
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

Methods of selectively synthesizing n-tetrasilane are disclosed. N-tetrasilane is prepared by catalysis of silane (SiH4), disilane (Si2H6), trisilane (Si3H8), or mixtures thereof. More particularly, the disclosed synthesis methods tune and optimize the n-tetrasilane:i-tetrasilane isomer ratio. The isomer ratio may be optimized by selection of process parameters, such as temperature and the relative amount of starting compounds, as well as selection of proper catalyst. The disclosed synthesis methods allow facile preparation of n-tetrasilane.

First claim

What is claimed is:

1. A method of selectively synthesizing n-tetrasilane, the method comprising:
producing a silane mixture having a n-Si 4 H 10 :i-Si 4 H 10 ratio ranging from approximately 5:1 to approximately 15:1 by reacting a Si n H (2n+2) reactant, wherein n=1-3, with a heterogeneous catalyst selected from a Group I, II or III element from the Periodic Table or oxides, alkyls, hydrides, silanides, or silyl amides thereof, and wherein the only catalyst used in the reaction is the heterogeneous catalyst selected from a Group I, II or III element from the Periodic Table or oxides, alkyls, hydrides, silanides, or silyl amides thereof.

2. The method of claim 1 , wherein the Si n H (2n+2) reactant is Si 3 H 8 .

3. The method of claim 2 , wherein the Si n H (2n+2) reactant is liquid Si 3 H 8 .

4. The method of claim 1 , wherein the Si n H (2n+2) reactant is a mixture of Si 2 H 6 and Si 3 H 8 .

5. The method of claim 1 , wherein the heterogeneous catalyst is selected from the group consisting of LiAlH 4 , LiAlH n R 4−n , NaAlH n R 4−n , KAlH n R 4−n , RbAlH n R 4−n , CsAlH n R 4−n , and combinations thereof, wherein n=1, 2,or 3 and each R is independently C m H 2m+1 with m=1-10 or an aliphatic group having an oxygen or nitrogen atom.

6. The method of claim 5 , wherein the heterogeneous catalyst is sodium bis(2-methoxyethoxy)aluminum hydride.

7. The method of claim 6 , wherein the ratio of n-Si 4 H 10 :i-Si 4 H 10 ranges from approximately 8:1 to approximately 15:1.

8. The method of claim 1 , wherein the heterogeneous catalyst is a Group I metal and Group I metal oxide.

9. The method of claim 1 , wherein the heterogeneous catalyst is a metal silylamide catalyst.

10. The method of claim 9 , wherein the metal silylamide catalyst is sodium bis(trimethylsilyl)am ide.

11. The method of claim 9 , wherein the metal silylamide catalyst is potassium bis(trimethylsilyl)amide.

12. The method of claim 11 , wherein the ratio of n-Si 4 H 10 :i-Si 4 H 10 ranges from approximately 8:1 to approximately 15:1.

13. The method of claim 1 , wherein the heterogeneous catalyst is a metal silanide catalyst.

14. The method of claim 13 , wherein the metal silanide catalysti is KSiPh 3 .

15. The method of claim 1 , further comprising isolating the n-Si 4 H 10 :i-Si 4 H 10 mixture from a Si a H (2a+2) mixture, wherein a=1-6.

16. The method of claim 1 , further comprising fractionally distilling the n-Si 4 H 10 :i-Si 4 H 10 silane mixture to produce a Si-containing film forming composition comprising approximately 95% w/w to approximately 100% w/w n-Si 4 H 10 .

17. A method of selectively synthesizing n-tetrasilane, the method comprising:
producing a n-Si 4 H 10 :i-Si 4 H 10 silane mixture having a ratio ranging from approximately 5:1 to approximately 12:1 by catalyzing liquid Si 3 H 8 using a catalyst selected from the group consisting of sodium, sodium oxide, sodium bis(2-methoxyethoxy)aluminum hydride, potassium bis(trimethylsilyl)amide (KN(SiMe 3 ) 2 ), lithium aluminum hydride (LiAlH 4 ), potassium triphenyl silicon (KSiPh 3 ), potassium hydride (KH), and mixtures thereof, wherein the only catalyst used in the reaction is selected from the group consisting of sodium, sodium oxide, sodium bis(2-methoxyethoxy)aluminum hydride, potassium bis(trimethylsilyl)amide (KN(SiMe 3 ) 2 ), lithium aluminum hydride (LiAlH 4 ), potassium triphenyl silicon (KSiPh 3 ), potassium hydride (KH), and mixtures thereof.

18. The method of claim 16 , further comprising isolating the n-Si 4 H 10 :i-Si 4 H 10 mixture from a Si a H (2a+2) mixture, wherein a=1-6.

19. The method of claim 17 , further comprising fractionally distilling the n-Si 4 H 10 :i-Si 4 H 10 silane mixture to produce a Si-containing film forming composition comprising approximately 95% w/w to approximately 100% w/w n-Si 4 H 10 .

Assignees

• Air Liquide
• Lair Liaquide Sa Pour Letude Et Lexploitation Des Procedes Georges Claude

Inventors

• Nikiforov Grigory
• Itov Gennadiy

Classifications

• B01J31/2213

  At least two complexing oxygen atoms present in an at least bidentate or bridging ligand · CPC title

• C01P2006/80

  Compositional purity · CPC title

• B01D3/009

  in combination with chemical reactions · CPC title

• C01B33/04 Primary

  Hydrides of silicon · CPC title

• B01J31/0275

  also containing elements or functional groups covered by B01J31/0201 - B01J31/0269 · CPC title