alpha-K4RI14Os (R = La, Pr): a novel iodine-rich structure with a layered network of electron-poor clusters. An incipient delocalized system with metal-like conductivity

Research was conducted to examine a novel network design which provides what appears to be an ideal connectivity for intercluster electron delocalization. The syntheses of alpha-K4R6I14Os (R = La, Pr), with their unusual cluster connectivities and all the delocalization implications thereof, clearly show how the introduction of alkali metals can lead to the formation of more open and less bridged structures. The 2D band calculations clearly shows the increased dispersion and delocalization that can be derived in the 2D-planar net of iodine-bridged clusters, which was the first unexpected feature of the new cluster structure.