Inorganic polysulfides: quantum chemistry study and biological implications

Abstract The storage and exchange of sulfane sulfur in inorganic polysulfides (HSnH, HSn- and Sn2-) are essential processes in cell signaling. We performed a benchmark study, in which wB97XD is most accurate among the investigated density functionals. Using wB97XD and a continuum model to account for the solvation effects of water, we studied polysulfides with n up to 30. Our computations suggest that long-chain polysulfides can serve as reservoirs of sulfane sulfur. Among the HSn- species, HS2- is the most nucleophilic, and is the most easily oxidized. For n > 4, the dianionic form of polysulfide is predominant.