Polythiazyl (polymeric sulfur nitride), (SN)x, is an electrically conductive, gold- or bronze-colored polymer with metallic luster.

[3][4] It is a fibrous solid, described as "lustrous golden on the faces and dark blue-black", depending on the orientation of the sample.

Burt, who obtained it by heating tetrasulfur tetranitride in vacuum over silver wool.

Along the fibres or SN chains, the bond is electrically conductive, perpendicular to it acts as an insulator.

[2][1][18] The reaction begins when silver abstracts sulfur from S4N4 to produce a Ag2S catalyst; the resulting gaseous S2N2 is then isolated through sublimation onto a cold surface: When warmed to room temperature, the additional heat induces spontaneous polymerization: Due to its electrical conductivity, polythiazyl is used in LEDs, transistors, battery cathodes, and solar cells.