Transmission of Substituent Effects through the Silicon-Silicon Bond

Article abstract of DOI:10.1021/ja00379a026

The transmission of substituent effects through the Si-Si bond was measured by monitoring 13C-1H coupling constants and 1H, 13C, and 29Si chemical shifts in substituted disilanes of the type XSi(CH3)2Si(CH3)3 (X = F, Cl, Br, CN, OC2H5, N(CH3)2, CH3) and through the NCH3 13C-1H coupling constants and basicities of the series XSi(CH3)2Si(CH3)2N(CH3)2 (X = Cl, OC2H5, N(CH3)2, CH3).Coupling constants and 1H and 13C chemical shifts correlated well with a variety of inductive parameters.Comparisons with the carbon analogues indicated that the C-C linkage transmits substituent effects about twice as effectively as the Si-Si bond.Indeed, the silicon-silicon bond in some systems behaves virtually as an insulator rather than conductor of substituent effects.This difference can be attributed to electrostatic field effects without recourse to (p-d)?, (d-d)?, or dative interactions.