Polythiazyl (polymericsulfurnitride), (SN)x, is an electrically conductive, gold- or bronze-colored polymer with metallic luster. It was the first conductive inorganic polymer discovered[1][2] and was also found to be a superconductor at very low temperatures (below 0.26 K).[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. It is air stable and insoluble in all solvents.[5]
^Labes, M. M.; Love, P.; Nichols, L. F. (1979). "Polysulfur Nitride - a Metallic, Superconducting Polymer". Chemical Reviews. 79 (1): 1–15. doi:10.1021/cr60317a002.