Tri-t-butylsilane has been prepared by treatment of t-butyllithium with HSiCl3 or HSiF3. Reactions of this compound with the halogens Cl2, Br2, I2, and the pentafluorides PF5 or SbF5 gave the expected tri-t-butylhalosilanes. With SO3 bis(tri-t-butylsilyl) sulfate is obtained via tri-t-butylsilanole. Reaction with dihalocarbenes obtained from phenyl(trihalomethyl)mercury compounds or the system haloform/base