Mutual transformation between mono- and binuclear ruthenium complexes and their reactions with iminobis(diisopropylphosphinesulfide) ligand

Treatment of RuCl3·xH2O, PPh3 and HCHO in boiling 2-methoxyethanol led to isolation of complex [(PPh3)(CO)ClRu(μ-Cl)3Ru(CO)(PPh3)2] (1) and [RuCl2(CO)(CH3OH)(PPh3)2] (2), which could convert to each other under special conditions. 1 could turn to 2 in MeOH/Et2O solvent in the presence of excess PPh3, while 2 could transform to 1 in CH2Cl2/n-hexane solvent. Reactions of complex 1 or 2 with KN[iPr2P(S)]2 afforded complex [{RuCl(CO)(PPh3)}2(μ-Cl)(μ-η2(S),η2(S′)-N(iPr2PS)2)] (3), in which the N[P(S)iPr2]2− ligand acts as a dinucleating tetraconnective unit through both sulfur atoms between two Ru(II) atoms. Complexes 1, 2, and 3 have been characterized spectroscopically and by X-ray crystallography.