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

The first structurally described cobalt(I) 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 σ-donor ligand SiCl2(IPr) through coordination with Co2(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 1H NMR and IR spectroscopy, single-crystal X-ray structural analysis, and density functional theoretical calculations.