Nonclassical Polysulfide Complexes: Cage and Ring Compounds [(MeCp)Ru(PPh₃)]₂S_x(x = 6, 4)

Aggregates of main-group elements are rich sources of ligands in transition-metal chemistry. Two topical classes of such ligands are polyatomic main group anions and cations. Metal polysulfide complexes may be viewed as derivatives of the simple Zintl ions S_x^2-. In principle such metalla-Zintl complexes would adopt cage and ring structures of the Gillespie type when rendered electron deficient. Previous work has shown, however, that electron deficiency in metal sulfides stabilizes terminal mono- and disulfido ligands. We now report results obtained in the course of our studies on organoruthenium sulfides that show a relationship between metallapolysulfides and polysulfur cations.