Abstract

The plasticity of the coordination chemistry of Lanthanoid ions (Ln) has allow the design of novel coordination compounds with slow relaxation of the magnetization since the first Single Ion Magnet (SIMs) was reported by Ishikawa1, who use phthalocyaninate ligand to make a “sandwich type” complex. Since, the coordination chemistry has allowed the possibility of design different types of molecular complexes with SIMs behaviour based on organic ligands.2 There is also mononuclear SIMs based on inorganic ligands, using different types of lacunary polyoxometalates (LPOM) like: [W5O18]6-, [XW11O39]7-/8- (X = PV and SiIV). However, the preparation of mononuclear hybrid organic-inorganic Ln complexes with SMM behaviour is a challenging task that remains unsuccessful. All the attempts in this direction have produced dinuclear or polynuclear systems. Moreover, the used of Ln complexes allow the possibility to obtained systems that can present interesting optical properties, since the ligand can work as an antenna, allowing the possibility of obtained fluorescents materials. The use of inorganic ligands, like LPOM, can cause a quenching of the emission properties since the existence of non-radiative transition of the LPOM.3 Herein we present the first isostructural family of mononuclear hybrid organic-inorganic lanthanoid complexes that present SIMs behavior. Specifically, the combination of phenanthroline ligand and the inorganic LPOM Keggin ligand under the appropriate conditions yield a molecular complex of formula [n-NBu4]3[LnH(PW11O39)(phen)2]·H2O (LnIII = DyIII, ErIII, GdIII, TbIII, HoIII, EuIII and NdIII.