High-nuclear heterometallic clusters of 3d/4f metals have received substantial recent interest due to their potential in the design of new magnetic materials used in quantum computing and molecular spintronics. Among them, the combination of high-spin Fe3+ ions with anisotropic Ln3+ ions led to the single molecule magnet behavior exhibited by some of the mixed polynuclear Fe-Ln clusters. Developing our previous work on the design and synthesis of Fe(III) carboxylate nanoclusters [1], we introduced into the reaction of trinuclear Fe(III) pivalates with azide and polyalcohol ligands lanthanide cations, e.g. Dy3+, Er3+, Ho3+ and Ce3+, to receive two types of Fe/4f heterometallic compounds as shown in Figure 1: the hexanuclear cluster [Fe4Ln2(piv)6(N3)4(Htea)4]∙n(solvent) (I) and the octanuclear cluster [Fe4Ce4O4(piv)4(N3)4 (tea)4(EtOH)] (II) (where Hpiv = pivalic acid; H3tea = triethanolamine, solvent = EtOH, CH2Cl2, Ln = Dy3+, Er3+, and Ho3+). Type I represents clusters with a wheel-shaped {Fe4Ln2} 18+ metallic core consisting of two pair of Fe(III) centers separated by Ln(III) ions all of which lie in the same plane, whereas type II has a condensed {Fe4Ce4} 24+ metallic core. In II, four Ce(III) atoms form a central tetrahedron (Ce···Ce, 3.718 and 3.750 Å) and are surrounded by four Fe(III) centers that are organized in a larger tetrahedron (Fe···Fe, 5.370 and 6.201 Å).figureFigure 1. {Fe4Ln2} (I, left) and {Fe4Ce4} (II, right) metallic cores in Fe-Ln clusters. Fe coordination environments are highlighted as dark grey polyhedra, Ln atoms, grey spheres.