Toroidal versus centripetal arrangement of the magnetic moment in a Dy4 tetrahedron

Magnetic investigation and ab initio calculations reveal toroidal arrangement of the magnetic moment rather than centripetal anisotropies in a tetrahedral Dy4 complex.

A cyanometallate- and carbonate-bridged dysprosium chain complex with a pentadentate macrocyclic ligand: synthesis, structure, and magnetism

A novel one-dimensional polymeric cyanometallate- and carbonate-bridged dysprosium(iii) chain with a pentadentate macrocyclic ligand exhibits field-induced multiple-relaxation processes.

Salen-type mononuclear dysprosium complex displays significant performance of single-molecule magnet

Three salen-type mononuclear lanthanide complexes with general formula [Ln(5-NO2salcy)(NO3)(CH3OH)2] (Ln = Dy (1), Ho (2) and Er (3)) have been designed and synthesized by reactions of N,N'-bis(5-nitrosalicylaldehyde)ethane-1,2-cyclohexanediamine (5-NO2salcyH2) with various...

Macrocycle based dinuclear dysprosium(III) single molecule magnets with local D5h coordination geometry

Targeted approaches for manipulating the coordination geometry of lanthanide ions are a promising way to synthesize high-performance single-molecule magnets (SMMs), but most of the successful examples reported to date focus on mononuclear complexes. Herein, we describe a strategy to assemble dinuclear SMMs with Dy^III ions in approximate D_5h coordination geometry based on pyrazolate-based macrocyclic ligands with two binding sites. A Dy4 complex with a rhomb-like arrangement of four Dy^III as well as two dinuclear complexes having axial chlorido ligands (Dy2·Cl and Dy2*·Cl) were obtained; in the latter case, substituting Cl^- by SCN^- gave Dy2·SCN. Magneto-structural studies revealed that the μ-OH bridges with short Dy-O bonds dominate the magnetic anisotropy of the Dy^III ions in centrosymmetric Dy4 to give a vortex type diamagnetic ground state. Dynamic magnetic studies of Dy4 identified two relaxation processes under zero field, one of which is suppressed after applying a dc field. For complexes Dy2·Cl and Dy2*·Cl, the Dy^III ions feature almost perfect D_5h environment, but both complexes only behave as field-induced SMMs (U_eff = 19 and 25 K) due to the weak axial Cl^- donors. In Dy2·SCN additional MeOH coordination leads to a distorted D_2d geometry of the Dy^III ions, yet SMMs properties at zero field are observed due to the relatively strong axial ligand field provided by SCN^- (U_eff = 43 K). Further elaboration of preorganizing macrocyclic ligands appears to be a promising strategy for imposing a desired coordination geometry with parallel orientation of the anisotropy axes of proximate Dy^III ions in a targeted approach.

Tuning the ligand field in seven-coordinate Dy(iii) complexes to perturb single-ion magnet behavior

Two mononuclear seven-coordinate Dy(iii) complexes with different strengths of ligand fields exhibit different slow magnetic relaxations.