Reactivity of [Ru4(μ-H)4(CO)12] with bidentate ligands containing at least one N-heterocyclic carbene moiety

► Reactions of [Ru4(μ-H)4(CO)12] with ditopic ligands. ► Thioether-, phosphine-, NHC- and pyridine-functionalized ditopic NHC ligands. ► CO-substitution reactions in [Ru4(μ-H)4(CO)12]. ► Detection of ionic reaction intermediates.