Study of the insertion products of manganese in the silicon-hydrogen bond. Nature of the bond and proton exchange in the H-Mn-Si-H system

Article abstract of DOI:10.1021/ic00131a066

NMR studies (²⁹Si, ¹³C, and ¹H) on silicon manganese hydrides slow the possibility of a bond interaction between silicon and hydrogen. Evidence is given for a slow intramolecular equilibrium (on the NMR time scale) between the silicon manganese hydride and the deinserted complex (silicon hydride and manganese moiety). In the latter, however, both moieties are associated and a strong ligand is needed to displace the silicon hydride. Chemical reactions show that protonation of the anion [(η⁵-CH₃C₅H₄)Mn(CO) ₂SiPh₃]^- leads only to the lateral hydride independent of its mode of generation. When the anion is alkylated, only the diagonal isomer is formed, showing that sterically crowded complexes prefer this geometry; thus the short distance observed between silicon and hydrogen does not seen to arise solely from steric hindrance.