Halogeno(pentafluorophenyl)silanes (C6F5)nSiX4-n(X=F, Cl, Br;n=2,3) and halogno(methyl)pentafluorophenylsilanes C6F5SiMenX3-n(X=F, Cl, Br; n=1,2) were prepared in good yields from the corresponding phenylsilanes (C6F5)n SiPh4-n and C6F5SiMenPh3-n by reactions with the electrophiles aHf, HCl - AlCl3, Br2 - AlBr3 or AlX3 (X=Cl, Br) - halogenated hydrocarbons. Additionally, reactions of (C6F5)2SiMe2 with selected electrophiles are studied and new synthetic routes to C6F5SiF3 are described. The relative leaving ability of organyl groups bonded to silicon and the role of the electrophilic reagent are discussed