Dinuclear ruthenium complexes containing tripodal dithiophosphonate ligands

Treatment of [(η6-p-cymene)RuCl(μ-Cl)]2 with Lawesson’s reagent [ArP(S)(μ-S)]2 (Ar = p-C6H4OMe) in the presence of ammonium hydroxide afforded the dinuclear complex [(η6-p-cymene)Ru{μ-η1(S),η2(S,S′)-ArP(O)S2}]2 (1) in which the tripodal [ArP(O)S2]2− ligands bind to the ruthenium atom in both bridging and chelating modes with two non-coordinating PO groups. Interaction of [RuHCl(CO)(PPh3)3] with [ArP(S)(μ-S)]2 and bis(diphenylphosphino)methane (dppm) in the presence of ammonium hydroxide gave the dinuclear complex [Ru(CO){μ3-η1(O),η2(S,S′)-ArP(O)S2}(dppm)]2 (2) in which the tripodal [ArPOS2]2− ligands bind the two Ru atoms via both sulfur and oxygen atoms. Treatment of [Ru(PPh3)3Cl2] with [ArP(S)(μ-S)]2 at reflux in the presence of ammonium hydroxide led to the formation of the dinuclear mixed valence complex [Ru2Cl2(μ-S){μ3-η1(O),η1(S),-η2(S,S′)-ArP(O)S2}(PPh3)3] (3), which contains a [RuII(PPh3)2Cl]+ and [RuIV(PPh3)Cl]3+ moieties by the tripodal [ArPOS2]2− ligand in a μ3-η1(O),η1(S),η2(S,S′) coordination mode and the μ-S2− anion. The crystal structures of 1, 2, and 3·CH2Cl2 along with their spectroscopic and electrochemical properties are reported.