9615. Tribromosilane

Nomenclature

CAS number: 7789-57-3
Tribromomonosilane; silicobromoform.
Br3HSi; mol wt 268.81.
Br 89.18%, H 0.37%, Si 10.45%.
SiHBr3.

Description and references

Prepd by passing hydrogen bromide over heated silicon or a silicide such as copper silicide: Schumb, Young, Inorg. Synth. 1, 38 (1939); Schenk in Handbook of Preparative Inorganic Chemistry vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd ed., 1963) pp 692-694.

Properties

Mobile liquid. Spontaneously flammable when the contact surface with air is large. d417 2.7. mp 73.5°. bp760 111.8°. The vapor pressure at 0° is given as 8.8 mm Hg. Dipole moment 0.79. Hydrolyzed by water with the formation of silicoformic anhydride, H2Si2O3 and HBr. Sol in chlorinated hydrocarbons.