The homoleptic low-spin complex [Fe(L)(3)](2+), where L is the bisbidentate ligand 1,10-phenanthroline-5,6-dione, coordinates Na+ ions via exo-oriented dione groups defining a three-dimensional cationic network {[Fe(L)(3)](4)Na-3}(11+)}(n) with Pt3O4 topology. The large volume generated by the network is filled with 11 perchlorate ions, 7 "NaClO4" ionic pairs, and 9 H2O molecules. Singular [Na+](4) units, in which the Na+ ions are practically uncoordinated, are formed.