Three ruthenocene derivatives:: (η5-4,7-dimethylindenyl)(η5-penta-methylcyclopentadienyl)ruthenium(II), [n5-[2](4,7)indeno[2]paracyclophanyl]-(η5-pentamethylcyclopentadienyl)-ruthenium(II) and bis[η5-[2](4,7)-indeno[2]paracyclophanyl]-ruthenium(II)

In the title compounds, [Ru(C10H15)(C11H11)], (III), [Ru-(C10H15)(C19H17)], (IV), and [Ru(C19H17)2], (V), respectively, the coordinating ring systems are planar and parallel, with the Ru atoms lying at perpendicular distances of Ru-Cp* 1.790 (1) Å and Ru-indenyl 1.836 (1) Å in (III), Ru-Cp* 1.791 (1) Å and Ru-indenyl 1.837 (1) Å in (IV), and Ru-indenyl 1.812 (1) Å and 1.809 (1) Å in (V) (Cp* is pentamethylcyclopentadienyl). The ring conformations are eclipsed for (III), staggered for (IV) and intermediate for (V). All three compounds show short intermolecular contacts from C-H groups to some ring centroids; these could be regarded as C-H⋯π hydrogen bonds. The molecules of each compound are thus connected via the 21 screw axis to form layers parallel to the xy plane.