HEXACHLORODISILANE Property

Melting point:

<0°C

Boiling point:

144-145.5 °C (lit.)

Density 

1.562 g/mL at 25 °C (lit.)

vapor pressure 

2.8hPa at 25℃

refractive index 

n20/D 1.475(lit.)

Flash point:

78°C

storage temp. 

below 5° C

solubility 

sol CHCl3, CH2Cl2, benzene, THF; reacts violently, producing toxic fumes, with H2O, alcohols.

form 

liquid

Specific Gravity

1.562

color 

Colorless to Almost colorless

Hydrolytic Sensitivity

8: reacts rapidly with moisture, water, protic solvents

Stability:

Stable, but reacts violently with water. Moisture sensitive. May be shock sensitive. Incompatible with water, moisture, acids, strong bases, oxidizing agents, alcohols.

CAS DataBase Reference

13465-77-5(CAS DataBase Reference)

EPA Substance Registry System

Disilane, hexachloro- (13465-77-5)

Safety

Hazard Codes 

C

Risk Statements 

14-34

Safety Statements 

26-36/37/39-45

RIDADR 

UN 2987 8/PG 2

WGK Germany 

3

F 

3-10-21

TSCA 

Yes

HazardClass 

8

PackingGroup 

II

HS Code 

28121049

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H314Causes severe skin burns and eye damage

Precautionary statements

P280Wear protective gloves/protective clothing/eye protection/face protection.

P303+P361+P353IF ON SKIN (or hair): Remove/Take off Immediately all contaminated clothing. Rinse SKIN with water/shower.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P363Wash contaminated clothing before reuse.

P405Store locked up.

HEXACHLORODISILANE Chemical Properties,Usage,Production

Chemical Properties

Hexachlorodisilane is a colourless liquid, it is highly sensitive to moisture, and when exposed to air or water, it readily reacts, making it essential to handle the compound in a controlled, moisture-free environment.

Physical properties

bp 144–145.5 °C; d 1.562 g/cm3.

Uses

Hexachlorodisilane can be used in deoxygenation and desulfurization of phosphine oxides, phosphine sulfides, and amine oxides; reducing agent for nitro groups and sulfur diimides.

Preparation

Hexachlorodisilane is prepared in the chlorination of silicides such as e.g. calcium silicide. Idealized syntheses are as follows: CaSi2 + 4 Cl2 → Si2Cl6 + CaCl2

Reactions

Hexachlorodisilane is a versatile chemical reagent that can be used in the following chemical reactions^[1-2]:
(1) When hexachlorodisilane is heated with a catalytic amount of triphenylphosphine or triphenylarsine, it decomposes according to the equation nSi2Cl6 = nSiCl4 + (SiCl2)n. It does not react with trifluoromethylphosphine. Hexabromodisilane is also decomposed by trimethylamine.
(2) Hexachlorodisilane reacts with hydrogen chloride in the presence of pyridine, and the reaction formula is:
Si2Cl6 + 2HCl = 2SiCl4 + H2.
(3) Excess hydrogen bromide and hexachlorodisilane produce a mixture of hydrogen chloride and hydrogen bromide.
(4) Hexachlorodisilane reacts with methyl chloride in the presence of triphenylphosphine to produce a mixture of methyltrichlorosilane and silicon tetrachloride. When hexachlorodisilane and methyl bromide are heated together in the presence of triphenylphosphine, a mixture of methyl chloride and bromine is produced.
(5) Hexachlorodisiloxane reacts with sulfur trioxide to produce silicon dioxide, sulfur dioxide and hexachlorodisiloxane.

General Description

Hexachlorodisilane (HCDS) is a chlorosilane used as a precursor for producing disilanes. It is a dioxidizer that is used in the production of silicon films and silicon nitride based films.

Flammability and Explosibility

Non flammable

Toxics Screening Level

The ITSL for hexachlorodisilane has been changed from 0.04 μg/m3 to 0.1 μg/m3 based on annual averaging time.

References

[1] H.J. EMELéUS; Muhammad T. Reaction of hexachlorodisilane with bases and alkyl halides[J]. Journal of Inorganic and Nuclear Chemistry, 1967. DOI:10.1016/0022-1902(67)80468-8.
[2] B. S. SURESH  D. P. Preparation of Hexafluorodisilane and Reactions of Hexafluorodisilane and Hexachlorodisilane with Sulfur Trioxide[J]. ACS Applied Electronic Materials, 1985. DOI:10.1246/BCSJ.58.1867.