Activations of all Bonds to Silicon (Si-H, Si-C) in a Silane with Extrusion of [CoSiCo] Silicide Cores

摘要

The [BP3iPr]Co(I) synthon Na-(THF)(6){[BP3iPr]CoI} (1, [BP3iPr] = kappa(3)-PhB((CH2PPr2)-Pr-i)(3)(-)) reacts with PhSiH3 or SiH4 to form unusual {[BP2iPr](SiH2R)CoH2}=Si={H2Co[BP3iPr]} species (R = Ph, 2a; R = H, 2b; [BP2iPr] = kappa(2)-PhB((CH2PPr2)-Pr-i)(2)) that result from activation of all Si-H and Si-C bonds in the starting silanes. Solution-spectroscopic data (multinuclear NMR, IR) for 2a,b, and the solid-state structure of 2a, indicate substantial Co=Si=Co multiple bonding and minimal interaction of the core Si atom with nearby hydride ligands. In the presence of 4-dimethylaminopyridine (DMAP), 1 reacts with PhSiH3 to give [BP3iPr](H)(2)CoSiHPh(DMAP) (3). Complexes 2a,b eliminate RSiH3 upon thermolysis in the presence of DMAP to generate {[BP2iPr]Co(NC5H3NMe2)}=Si={H2Co[BP3iPr]} (4).