Formation of one dimensional linear chains by Ir-Ir bonds in cis-dicarbonyldichloroiridate (I)

► Electronic properties of K[IrCl2(CO)2]H2O related to supramolecular structure. ► Formation of one dimensional linear chains of Ir-Ir with at least 12 Ir atoms. ► The Ir-Ir distance is 2.82 ± 0.01 Å, short enough to assume a metal-metal bond. ► Monomers placed parallel in helical arrangement making 360° turn after 8 units.