Multicenter electron-sharing σ bonding in the AgFe(CO)4– complex

Heterodinuclear silver tetracarbonyl–iron anion was generated in the gas phase and studied by a joint photoelectron velocity map imaging spectroscopy and quantum chemical calculations. The AgFe(CO)4– anion is characterized to be an 18-electron complex with the silver atom as covalently ligand bonded to the anionic tetracarbonyl–iron, an isolobal analogue of methyl radical. The bonding analyses by using a range of state-of-the-art quantum chemistry methods reveal a peculiar decentralized bonding situation where the silver atom is covalently bonded to both the iron center and the vicinal carbon atoms in the form of electron-sharing σ bond.