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.