Synthesis and NMR investigation of selenobutyl substituted silanes and oligosilanes

The reaction of BuSeLi, made from BuLi and elemental selenium, with chloros ilanes MexPhySiCl4-x-y led to selenobutyl substituted derivatives. In the c ases of polychlorosilanes formation of the completely substituted products MexPhySi(SeBu)(4-x-y) are favoured. Higher yields of partially substituted products could be obtained by reaction of chlorosilanes with BuSeH/NEt3. Be sides monosilanes the reactions of several methylchlorodi-, tri- and isotet rasilanes with BuSeLi and BuSeH/NEt3 were also investigated. In SiClMe(SiCl Me2)(2) the chlorine substituent at the middle silicon atom is substituted by BuSeH/NEt3 at first selectively. All products were characterized by H-1, C-13, Si-29 and Se-77 NMR and trends of chemical shifts and coupling const ants ((1)J(SiSi), (1)J(SiSe), (2)J(SiSe)) with the substitution pattern wer e investigated.