Process and device for the production of polyhedral boranes

Patent metadata

Field	Value
Publication number	US-9598352-B2
Application number	US-201214357684-A
Country	US
Kind code	B2
Filing date	Nov 16, 2012
Priority date	Nov 18, 2011
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

The present invention provides methods and devices for producing polyhedral boron compounds. The process is generally an anhydrous, one-pot process that comprises a pyrolytic reaction of a tetraborohydride with a quaternary amine salt to form the polyhedral borane. In another aspect of the present invention, polyhedral boranes are produced, without isolation of the Lewis base-borane complex.

First claim

What is claimed is:

1. A process for the production of a polyhedral borane in an amount greater than one kilogram, wherein the process comprises a solid-phase, anhydrous, one-pot reaction of a tetraborohydride and a quaternary amine salt under anhydrous pyrolytic reaction conditions without solvent, resulting in the formation of the polyhedral borane.

2. The process of claim 1 , wherein the tetraborohydride is chosen from sodium borohydride, potassium borohydride, and lithium borohydride.

3. The process of claim 1 , wherein the quaternary amine salt of Formula (I), wherein L 1-4 are independently chosen from hydrogen, hydrocarbyl, and substituted hydrocarbyl, and X − is chosen from F − , Cl − , Br − , I − , and OH −

4. The process of claim 1 , wherein the quaternary amine salt is tetraethyl ammonium chloride.

5. The process of claim 1 , wherein the pyrolytic conditions comprise a temperature of at least 180° C., and a pressure of at least 0.5 atmospheres.

6. The process of claim 1 , wherein the reaction time is at least 5 hours.

7. The process of claim 1 , wherein the polyhedral borane is a borane anion.

8. The process of claim 7 , wherein the borane anion is B 10 H 10 2− or B 12 H 12 2− .

9. The process of claim 1 , wherein the reaction occurs in the presence of a catalyst.

10. The process of claim 9 , wherein the catalyst is a Lewis acid in a ratio of about 0.1 to about 5 mol% of the tetraborohydride.

11. The process of claim 1 , wherein the tetraborohydride and the quaternary amine salt are present in a ratio between 1:1.3 to 1:1.5.

12. The process of claim 1 , wherein B 10 H 10 2− is selectively produced in a yield of at least about 40%.

13. The process of claim 1 , wherein B 12 H 12 2− is selectively produced in a yield of at least about 50%.

14. The process of claim 1 , wherein the pyrolytic reaction occurs in a milling reactor.

15. A process for the selective formation of B 12 H 12 2− over B 10 H 10 2− in an amount greater than one kilogram, the process comprising (a) combining a borohydride with a quaternary amine salt to form an anhydrous reaction mixture; and (b) subjecting the anhydrous reaction mixture to solid-phase, anhydrous pyrolytic reaction conditions without solvent, comprising at least a temperature of 180° C. for at least 12 hours such that the majority of the borohydride is converted to B 12 H 12 2− .

16. The process of claim 15 , further comprising the steps of:
(a) quenching the pyrolytic reaction with a quench reagent, and
(b) purifying the resultant reaction mixture to isolate one or more polyhedral boranes.

17. The process of claim 16 , wherein the quench reagent is selected from weak acids and bases.

18. The process of claim 17 , wherein the quench reagent is acetic acid.

19. The process of claim 16 , wherein purification is accomplished by washing the reaction mixture with an alcohol chosen from methanol, ethanol, propanol, allyl alcohol, and butanol.

20. The process of claim 19 , wherein the alcohol is methanol.

Assignees

• Univ Missouri

Inventors

• Lee Mark Wayne
• Hawthorne Marion Frederick

Classifications

• C07C211/63 Primary

  having quaternised nitrogen atoms bound to acyclic carbon atoms · CPC title

• C01B35/026 Primary

  Higher boron hydrides, i.e. containing at least three boron atoms · CPC title