A straightforward and generalizable synthetic methodology for the synthesis of ruthenium(II) complexes with thioether ligands from either Ru(III) or Ru(0) precursors.

The reaction of Ru(3)(CO)(12) in chloroform with thioether ligands after 25 min of irradiation leads to the formation of mononuclear ruthenium(II) complexes of the general formula fac-[Ru(CO)(3)Cl(2)(S)] (S = thioether) if monodentate ligands are introduced. In the case of chelating bidentate thioethers a complex of the formula all-cis-[Ru(CO)(2)Cl(2)(S[intersection]S)] is produced. If irradiation time is prolonged to 2.5 h mononuclear complexes of the composition trans-[RuCl(2)(S)(4)] or trans-[RuCl(2)(S[intersection]S)(2)] are observed. The use of tetrahydrothiophene (THT) in the latter case produces a dinuclear ruthenium(ii) complex of the formula [Ru(2)(CO)(2)Cl(4)(THT)(2)(mu-THT)(2)] which is the first structurally characterized neutral ruthenium complex with a bridging thioether ligand. Regardless of the used ligand complexes trans-[RuCl(2)(S)(4)] or trans-[RuCl(2)(S[intersection]S)(2)] are formed from the reaction of RuCl(3).3H(2)O with the corresponding thioether in the presence of NEt(3) and formaldehyde in excellent yields. Six new ruthenium complexes are characterized by X-ray diffraction.