The properties of the carbon sulfide C6S8 (1) as well as its dioxo analogue C6S6O2 (2) have been studied in the fully oxidized and fully reduced forms, i.e., 1(0), 1,(2-) 2(0), 2(2-). A crystallographic study shows that compound 2 is a tricyclic species with a twisted 1,2-dithiin (unsaturated C4S2 ring) core. Reduction of 1 with 2 equiv of LiBHEt3 gave C6S82-(1(2-)), which was isolated as its PP4+ salt. A crystallographic study of this salt shows that reduction has resulted in cleavage of the S-S bond and that, in the solid state, the dihedral angle between the two rings is 180 degrees. Both 1(2-) and 2(2-) undergo two sequential and reversible 1e(-) oxidations near 0 V (vs Ag/AgCl), thus establishing that 1(0) and 2(0) are good oxidants relative to other disulfides. Treatment of (PPh4)(2)[C6S8] with [Ni(H2O)(6)]Cl-2 afforded the dark red (PPh4)(2)[Ni(C6S8)(2)] (3). The analogous Pt complex (4) was also prepared. Crystallographic analysis of 3 shows that the nickel center is square planar, comprising two seven-membered NiS2C4 rings. The paramagnetism observed for solutions of 3 are attributed to the formation of a tetrahedral isomer.