Improved syntheses for the trisilanes (PhH2Si)2SiHPh, (PhH2Si)2SiH2 an
d (Ph2HSi)2SiPh2 are reported. The preparation of (Ph2HSi)2SiH2 and Ph
2HSiSiH2SiH2Ph is described for the first time. When octaphenyltrisila
ne, 2-chloro-1,1,1,3,3,3-hexaphenyltrisilane or 1,1,1,3,3,3-hexaphenyl
trisilane react with liquid hydrogen chloride or triflic acid (CF3SO3H
), trisilanes (PhCl2Si)2SiClPh, (PhCl2Si)2SiHCl, (Ph2TfSi)2SiPh2 (Tf =
CF3SO3), (Ph2TfSi)2SiH2 and Ph2TfSiSiH2SiPhTf, are formed which are e
asily reduced to the title compounds using LiAlH4.