2857-97-8

Clear yellow liquid

bp 79°C; d 1.188 g cm?3; n20 D 1.4240; fp 32°C.

although many methods are reported, only a few are provided here: chlorotrimethylsilane undergoes halogen exchange with either magnesium bromide in Et2O or sodium bromide in MeCN, which allows in situ reagent formation (eq 1); alternatively, hexamethyldisilane reacts with bromine in benzene solution or neat, to afford only TMS-Br with no byproducts (eq 2).4 TMS-Br may also be generated by reaction of hexamethyldisiloxane and aluminum bromide (eq 3).However, it should be noted that the reactivity of in situ generated reagent appears to depend upon the method of preparation.

Purify it by repeated fractional distillation and store it in sealed ampoules in the dark. [McCusker & Reilly J Am Chem Soc 75 1583 1953.] Also fractionate it through a 15-plate column (0.8 x 32cm packed with 1/16in single turn helices of Pt-Ir wire). [Gilliam et al. J Am Chem Soc 68 1161 1946, Pray et al. J Am Chem Soc 70 433 1948, Beilstein 4 IV 4008.]