| Title:  Tribromosilane CAS Registry Number:  7789-57-3 Additional Names:  Tribromomonosilane;  silicobromoform Molecular Formula:  Br3HSi Molecular Weight:  268.81 Percent Composition:  Br 89.18%, H 0.37%, Si 10.45% Line Formula:  SiHBr3 Literature 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. Melting point:  mp -73.5° Boiling point:  bp760 111.8° Density:  d417 2.7  |