The reactions of the NHC-functionalized phosphines 1-[{2-(diphenylphosphino)­phenyl}­methyl]-3-methylimidazol-2-ylidene (Ph2PC6H4CH2ImMe) and 1-[{2-(dicyclohexylphosphino)­phenyl}­methyl]-3-methylimidazol-2-ylidene (Cy2PC6H4CH2ImMe) and the NHC-functionalized thioether 1-{(2-methylsulfide)­ethyl}-3-methylimidazol-2-ylidene (MeSCH2CH2ImMe) with [Ru3(CO)12] have been studied. Both NHC-phosphines react with equimolar amounts of [Ru3(CO)12], in THF at room temperature, to give the edge-bridged disubstituted products [Ru3(μ-κ2 P,C NHC-R2PC6H4CH2ImMe)­(CO)10], R = Ph (1), Cy (2), which selectively undergo a double C–H bond activation of their CH2 group upon gentle warming (R = Ph) or at room temperature (R = Cy) to give the dihydrido derivatives [Ru3(μ-H)2(μ3-κ3 P,C,C NHC-R2PC6H4CImMe)­(CO)8], R = Ph (3) and Cy (4), respectively. These products contain novel face-capping ligands that arise from the oxidative addition of both C–H bonds of the corresponding NHC-phosphine ligand CH2 group. This double-metalation process is facilitated by the rigidity of the C6H4CH2 linker of these ligands. The treatment of [Ru3(CO)12] with 3 equivalents of Ph2PC6H4CH2ImMe leads to the mononuclear ruthenium(0) complex [Ru­(κ2 P,C NHC-Ph2PC6H4CH2ImMe)­(CO)3] (5). No trinuclear derivatives were obtained from reactions of [Ru3(CO)12] with MeSCH2CH2ImMe, the tetranuclear derivative [Ru4(μ-κ2 S,C NHC-MeSCH2CH2ImMe)­(μ-CO)2(CO)10] (6) being the only product that could be isolated. Compound 6 contains a butterfly arrangement of the metal atoms with the wing tips bridged by the ligand sulfur atom, while the NHC fragment is attached to one wing tip.

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Two structurally related tetranuclear complexes, [Ru4(μ4‐κ2C,S‐IMe–CS)(μ4‐S)(μ‐CO)2(CO)9] (1) and [Ru4(μ4‐κ2C,N‐TMe–CNPh)(μ4‐S)(μ‐CO)(CO)10] (2), have been isolated from reactions of [Ru3(CO)12] with 1 equiv. of the betaines IMe–CS2 (IMe = 1,3‐dimethylimidazol‐2‐ylidene) and TMe–C(S)NPh (TMe = 3‐methylthiazol‐2‐ylidene), respectively. Both products contain μ4‐S ligands that arise from the unprecedented cleavage of the thiocarbonyl C–S bonds of the corresponding betaines. A hexanuclear derivative, [Ru6{μ3‐κ4C2,N,S‐S(CH)2N(Me)CCNPh}2(μ4‐S)2(CO)14] (3), has also been obtained from the reaction involving TMe–C(S)NPh. This product arises not only from the cleavage of the betaine thiocarbonyl C–S bond, but also from the additional activation of the C–S bond within the thiazole ring.

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