Dinuclear Metal Complexes of a New Hybrid Phosphine-Phosphonodithioate Ligand

Abstract Reaction of Ph2PCH2OH and {RP(S)(μ-S)}2 (R = p-C6H4OMe, Lawesson's reagent), in toluene, gave the new hybrid PIII/PV ligand Ph2PCH2OP(S)(R)SH 1 in high yield. Unfortunately, attempts to crystallise 1 gave, instead, suitable X-ray quality crystals of the Zwitterion Ph2P+(CH2OH)CH2OP(S)(R)S− 1`, presumably arising from the presence of some residual formaldehyde. Three homodinuclear complexes [Ru2(η6-p-CH3C6H4iPr)2{μ-Ph2PCH2OP(S)(R)S}Cl3] (2) and [M2(η5-C5(CH3)5)2{μ-Ph2PCH2OP(S)(R)S}Cl3] [M = Rh, 3; M = Ir, 4 (R = p-C6H4OCH3)] were obtained upon reaction of a 1:1 molar ratio of 1 and either [(η6-p-CH3C6H4iPr)RuCl(μ-Cl)]2 or [M(μ-Cl)(Cl)(η5-C5(CH3)5)2]2 (M = Rh and Ir), respectively. The mononuclear IrIII complex Ir(η5-C5(CH3)5)(Ph2PCH2OH)Cl2 5 was prepared for comparative spectroscopic and crystallographic purposes with 4. All compounds were characterised by a combination of multinuclear NMR and FT−IR spectroscopy and elemental analysis. In addition, the first example of a phosphine-dithiophosphonate ligand 1` along with two homodinuclear complexes 2•CHCl3 and 4 were determined by single crystal X-ray diffraction. Compound 5 displays an intramolecular O(1)−H(1)•••Cl(2) hydrogen bond to a terminal IrIII bound chloride ligand.