AbstractCrystals of [Pt2(n‐pentylCS2)4I] show a transition from semiconductor to metallic with the increase of the temperature (conductivity is 0.3–1.4 S · cm−1 at room temperature) and a second metallic–metallic transition at 330 K, inferred by electrical conductivity measurements. X‐ray diffraction studies carried out at different temperatures (100, 298, and 350 K) confirm the presence of three different phases. The valence‐ordering of these phases is analyzed using structural, magnetic, and electrical data. Density functional theory calculations allow a further analysis of the band structure derived for each phase. Nanostructures adsorbed on an insulating surface show electrical conductivity. These results suggest that MMX‐polymer‐based nanowires could be suitable for device applications.