Lewis-Base-Stabilized Dichlorosilylene: A Two-Electron σ-Donor Ligand

The first structurally described cobalt(l) Lewis-base-stabilized silylene complex [Co(CO)(3){SiCl2(IPr)}(2)](+)[CoCl3(THF)](-) [1; IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene] was prepared by applying the two-electron sigma-donor ligand SiCl2(IPr) through coordination with Co-2(CO)(8). The bonding situation between ligand SiCl2-(IPr) and the cobalt(I) metal center in [Co(CO)(3){SiCl2(IPr)}(2)](+) of 1 was investigated by H-1 NMR and IR spectroscopy, single-crystal X-ray structural analysis, and density functional theoretical calculations.