Amidinate-Stabilized Group 9 Metal-Silicon(I) Dimer and -Silylene Complexes.

The coordination chemistry of the amidinate-stabilized silicon(I) dimer toward group 9 metal complexes is described. The reaction of [LSi:]2 (1, L = PhC(NtBu)2) with [Ir(cod)Cl]2 (cod = 1,5-cyclooctadiene) in toluene at ambient temperature afforded the base-stabilized silicon(I) dimer-iridium complex [LSi{Ir(cod)-μ-Cl-Ir(cod)}SiL][(cod)IrCl2] (2). In contrast, the reaction of 1 with [Rh(cod)Cl]2 in toluene at ambient temperature afforded a mixture of the amidinate-stabilized silicon(I) dimer-rhodium complex [LSi{Rh(cod)-μ-Cl-Rh(cod)}SiL] (3) and the dimeric amidinate-stabilized rhodosilylene [(LSi)μ-{Rh(μ-Cl)2Rh(cod)}]2 (4). Moreover, the latter reacted with PPh3 to afford a mixture of the Wilkinson's catalyst [(PPh3)3RhCl] and the dimeric rhodosilylene complex [(LSi)μ-{RhCl(PPh3)}]2 (5), which underwent a rearrangement to form the rhodosilylene-phosphidorhodium dimer (LSi)μ-{RhCl(PPh3)}μ-{RhCl(LSiPh)} (6). Compounds 2-6 were characterized by NMR spectroscopy and X-ray crystallography. In addition, DFT calculations of compound 4 were performed to understand its electronic structure.