Role of the Templating Heteroatom on Both Structural and Magnetic Properties of POM-Based SIM Lanthanoid Complexes

The plasticity of the coordination chemistry of Lanthanoid ions (LnIII) has allow the design of novel coordination compounds with slow relaxation of the magnetization since the first Single Ion Magnet (SIMs) was reported by Ishikawa, who used the phthalocyaninate ligand to make a “sandwich type” complex. The coordination chemistry has allowed the possibility to design different types of molecular complexes with SIMs behaviour based on organic ligands. There is also SIMs based on inorganic ligands, using different types of lacunary polyoxometalates (LPOM) like, [XW11O39]n−. The combination of both types of ligands can produce hybrid inorganic-organic LnIII complexes with SIM behaviour. This is an attractive approach since these hybrid materials could benefit from the combination of the ease of functionalization of the organic ligands with the robustness of the inorganic moieties. There are reports that a hybrid mononuclear DyIII complex could improve the relaxation dynamics when it is compared to the inorganic analogues. Thus, in this review we present a study and comparison on the improvement that inorganic and organic ligands can cause to the geometry of the metal centres of fully inorganic and hybrid (mononuclear and dinuclear) lanthanoid complexes (for DyIII, ErIII and YbIII). Moreover, we will discuss which of these changes can modify the magnetic properties of the Lanthanoid Complexes.