The mononuclear complex [Yb(H3L1,1,4)]•2MeOH (1•2MeOH), with a new heptadentate N4O3 ligand, was isolated and structurally characterised. The opto magnetic properties of 1•2MeOH were investigated, showing that this complex is a...

A new HL Schiff base ligand with three defined compartments, namely, two internal NNO and one external O, was designed to allocate metal ions of different size. This ligand allows isolating heterodinuclear [ZnLn(HL)(NO)(OAc)(D)](NO) (Ln = Tb, D = HO, ZnTb; Ln = Dy, D = CHOH, ZnDy; and Ln = Er, D = CHOH, ZnEr) complexes, where one of the NNO pockets allocates a zinc(II) ion, while the other one is empty, or heterotrinuclear [ZnLn(L)(NO)(OAc)(HO)] (Ln = Dy, ZnDy and Ln = Er, ZnEr) compounds, where each NNO compartment accommodates Zn. All these compounds crystallize with different solvates, and their structures were unequivocally determined by single-crystal X-ray diffraction studies. Complexes ZnDy, ZnDy, and ZnEr behave as single-molecule magnets in the presence of an external dc field of 1000 Oe, with U values of 41.05, 47.69, and 20.81 K, respectively, while ZnTb and ZnEr do not.

Mononuclear complexes of stoichiometry [Ln(HL)(HO)(NO)](NO) (Ln = Tb, 1; Dy, 2, Er, 3), which crystallise with different solvates, and the heterotrinuclear compound [ZnDy(L)(NO)(OH)] (4) can be obtained with the same HL compartmental ligand. The single X-ray crystal structure of the mononuclear complexes shows a LnO core with a muffin-like disposition while the geometry of the DyO core in 4 seems to be closer to spherical capped square antiprism. The analysis of the magnetic properties of all the complexes demonstrates that the mononuclear lanthanide compounds do not show slow relaxation of the magnetization, even when the samples are diluted with a diamagnetic matrix and subjected to a dc applied field of 1000 Oe. Nevertheless, the heterotrinuclear dysprosium complex 4·3HO is a field-induced single ion magnet, with an estimated U barrier of 59 K. The luminescence characterisation of all the metal complexes in methanol solution at 298 K also shows a notable increase in the fluorescence emission of the heterotrinuclear complex with respect to the mononuclear ones, in such a way that 4 can be defined as a fluorescent single ion magnet.