Centrosymmetric [Mn2(CO)6(μ-thpymS)2] (thpymS = tetrahydropyrimidine-2-thionato) as a synthon to mixed-metal clusters

Reaction of [Mn2(CO)9(NCMe)] with tetrahydropyrimidine-2-thione (thpymSH) at 25 °C furnishes the mono- and dinuclear complexes [Mn(CO)4(κ1:η1-SCNHC3H6NCO)] (2) and [Mn2(CO)6(μ-thpymS)2] (1), respectively. Carbon–nitrogen coupling is observed in compound 2 resulting in the formation of κ1:η1-SCNHC3H6NCO ligand while compound 1 adopts a centrosymmetric structure. Reaction of 1 with [Os3(CO)10(NCMe)2] at 80 °C affords the mixed Mn–Os cluster [MnOs3(CO)13(μ3-thpymS)] (3) which possesses a butterfly skeleton of four metal atoms whereas with Ru3(CO)12 at 110 °C gives the mixed Mn–Ru complex [MnRu3(CO)14(μ4-S)(κ1:η1-thpym)] (4). In contrast, treatment of 1 with Fe3(CO)12 at 80 °C furnishes two triiron complexes [Fe3(CO)9(μ3-S)(μ3-κ1:η1-C4H6N2)] (5) and [Fe3(CO)8(μ3-S)2(η1-C4H8N2)] (6). The former also results from the direct reaction of thpymSH with Fe3(CO)12 and reacts with H2S to afford 6. The molecular structures of all these new complexes have been determined by X-ray diffraction studies.

Several mono- and bimetallic metal carbonyl complexes are synthesized using tetrahydropyrimidine-2-thione as a ligand.Figure optionsDownload as PowerPoint slideHighlights
► Synthesis of centrosymmetric dimanganese complex [Mn2(CO)6(μ-thpymS)2].
► Carbon–nitrogen coupling.
► Synthesis of Os–Mn mixed-metal clusters containing tetrahydropyrimidine-2-thionato ligand.
► Synthesis of Ru–Mn mixed-metal clusters containing μ4-sulfido and 2-tetrahydropyrimidyl ligands.
► Synthesis of triiron cluster containing heterocyclic carbene.