Abstract

The crystal structures of [Rb[2.2.2]crypt]2[Mn2(CO)8] ⋅ 4NH3 and [K[18]crown-6]2K2[W2(CO)8] ⋅ 14NH3 are reported, containing the first homoleptic dinuclear carbonyl metalates featuring metal−metal double bonds. [Mn2(CO)8]2− and [W2(CO)8]4− are isostructural and isoelectronic to the elusive [Fe2(CO)8]. Quantum chemical calculations and QTAIM analysis confirm the metallic bonding character, as well as differences in terminal and bridging carbonyl ligands.