Darstellung und eigenschaften von heterocyclischen silanen des typs Si4X MIT X = B,N, O

Five-membered heterocycles Si₄Ph₈X with X = BNMe₂, NMe, NEt and O were prepared and characterised with ¹H NMR, UV, far IR and Raman spectra. The problem of electron delocalisation in these ring systems containing an electron excess (N) or an electron deficit (B), respectively, is discussed. These measurements suggest that there is no delocalisation.