PREPARATION AND SPECTROSCOPIC CHARACTERIZATION OF BRANCHED FUNCTIONAL HEXASILANE STRUCTURES

When 2-chloro-1,1,1,3,3,3-hexaphenyltrisilane is treated with an excess of HCl in a stainless steel autoclave, two phenyl groups per silicon atom are substituted by Cl yielding 1,1,2,3,3-pentachloro-1,3-diphenyltrisilane. All phenyl groups are replaced upon treatment with HCl/AlCl3 in benzene solution. Coupling of the resulting trisilanes with ((t)Bu)2Hg leads to branched hexasilanes (XCl2Si)2SiClSiCl(SiCl2X), (X = Ph, H), which are converted to the corresponding silicon hydrides by LiAlH4. From the reaction of 1,4-diphenyl-2,3-bis(phenylsilyl)tetrasilane with HCl or HBr the tetrahalohexasilanes (ClH2Si)2SiHSiH(SiH2Cl)2 and (BrH2Si)2SiHSiH(SiH2Br)2 can be obtained.