Tetrasulfur Tetranitride - Polythiazyl

Polythiazyl

Passing gaseous S₄N₄ over silver metal yields the low temperature superconductor polythiazyl or polysulfurnitride (transition temperature (0.26±0.03) K), often simply called "(SN)_x". In the conversion, the silver first becomes sulfided, and the resulting Ag₂S catalyzes the conversion of the S₄N₄ into the four-membered ring S₂N₂, which readily polymerizes.

S₄N₄ + 8 Ag → 4 Ag₂S + 2 N₂

S₄N₄ → (SN)_x