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