DFT study on C-C bond cleavage of nitriles by a silyl(silylene)iron complex

The unsaturated disilanyl iron (II) complex Cp∗Fe(CO)SiMe2SiMes2Me is regard as a key intermediate in the reactions of the C-C bond cleavage of nitriles. The C-C bond cleavage of nitriles occurs after 1,2- and 1,3-group migration reactions in the organosilicon moieties. This reaction mechanism of the cleavage of C-C bond of nitriles by the Silyl(silylene) iron complex was investigated in detail with Gaussian98 package at the Becke3LYP (B3LYP) level of the density functional theory. The effective core potentials of Hay and Wadt with a double-basis set (LanL2DZ) were used to describe Fe, Si atoms, and the standard 6-31 G basis set was used for H, C, N, and O atoms. Polarization functions were also added for Si (ζd = 0.262), C (ζd = 0.8) and those atoms directly involved in bond-forming and bond-breaking processes. The C-C bond rupture of nitriles by the Silyl(silylene) ruthenium complex was also studied and we found that the induction effect of Silyl(silylene) iron complex should be better.