Coordination cages based on organometallic half-sandwich complexes are of interest, because they can display unique structures and host properties. This communication describes the synthesis and structure of a cylindrical nanostructure containing six (p-cymene)Ru-II fragments. The complex was obtained by reaction of [(p-cymene)RuCl2](2) with a novel C-3-symmetrical ligand containing a triarylamine core and three dihydroxypyridine groups in its periphery. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)