Synthesis and reactivity of the ruthenium(II) dithiocarbonate complex [Ru(kappa2-S2C=O)(dppm)2] (dppm = bis(diphenylphosphino)methane)

Reaction of cis-RuCl2(dppm)2] (dppm = bis(diphenylphosphino)methane) with CS2 and NaOH yields the first ruthenium dithiocarbonate complex, Ru(kappa2-S2C=O)(dppm)2]. Protonation with tetrafluoroboric acid affords the xanthate complex Ru(kappa2-S2COH)(dppm)2]BF4 in a reversible manner, suggesting that this may be an intermediate in dithiocarbonate formation. Ru(kappa2-S2C=O)(dppm)2] reacts with methyl iodide or Me3O]BF4 to give Ru(kappa2-S2COMe)(dppm)2]+, also obtained from the reaction of cis-RuCl2dppm)2] with CS2 and NaOMe. Two modifications of Ru(kappa2-S(2)C=O)(dppm)2] were examined crystallographically and the structure of Ru(kappa2-S2COMe)(dppm)2]BF4 and a new modification of cis-RuCl2(dppm)2] are also reported.