Composition comprising neopentasilane and method of preparing same

1. A composition comprising:

at least 93% (w/w) of neopentasilane;

not greater than 5% (w/w) of other silanes; and

not greater than 2% (w/w) of hydrocarbons.

2. The composition according to claim 1 , wherein the composition comprises at least 97% (w/w) by neopentasilane.

3. The composition according to claim 1 , wherein the composition comprises not greater than 3% (w/w) by other silanes.

4. The composition according to claim 1 , wherein the composition comprises not greater than 1% (w/w) by hydrocarbons.

5. A method of preparing a composition comprising neopentasilane, the method comprising:

(i) treating a hexahalodisilane having the formula X 3 SiSiX 3 , wherein X is —Cl or —Br, with a tertiary amine catalyst to produce a first mixture comprising a tetrakis(trihalosilyl)-silane and a silicon tetrahalide;

(ii) separating the tetrakis(trihalosilyl)silane and the silicon tetrahalide;

(iii) treating the separated tetrakis(trihalosilyl)silane with diisobutylaluminum hydride to produce a second mixture comprising neopentasilane; and

(iv) distilling the second mixture to remove the neopentasilane.

6. The method according to claim 5 , wherein the hexahalodisilane is hexachlorodisilane.

7. The method according to claim 5 , wherein the tertiary amine catalyst is 1,4-diazabicyclo[2.2.2]octane.

8. The method according to claim 5 , wherein the concentration of the tertiary amine catalyst is from 0.01 to 1% (w/w), based on the weight of the hexahalodisilane.

9. The method according to claim 5 , wherein step (iii) and step (iv) are carried out in sequential order.

10. The method according to claim 5 , wherein step (iii) and step (iv) are carried out simultaneously.

11. The method of claim 5 , wherein the mole ratio of the diisobutylaluminum hydride to the tetrakis(trihalosilyl)silane is from 12 to 14.