Inorganic polysulfides Sn2- and radical anions Sn•-

Inorganic polysulfide anions S-n(2.-) and the related radical anions S-n(-) play an important role in the redox reactions of elemental sulfur and therefore also in the geobiochemical sulfur cycle. This chapter describes the preparation of the solid polysulfides with up to eight sulfur atoms and univalent cations, as well as their solid state structures, vibrational spectra and their behavior in aqueous and non-aqueous solutions. in addition, the highly colored and reactive radical anions S-n(.-) with n = 2, 3, and 6 are discussed, some of which exist in equilibrium with the corresponding diamagnetic dianions.